Engineering Design
a) Building Engineering Design Management necessitates an integrated approach to formulate an overall philosophy, able to achieve an intellectual product covering & incorporating a wide range of performance & serviceability requirements that shall completely meet intended functions of the proposed building adequately satisfying architectural, structural & allied services requirements. The target achievement of this fast track EPC project shall be kept in consideration by all discipline designers to release the necessary documents on planned line.
To accomplish this part of the package to the best possible standards, AJES shall invite certain (possibly 3) reputed & leading architectural engineering Firms as Engineering Services sub contractor. Based on the merits of each offer as well as applying the competency criteria, a preliminary selection shall be made. After obtaining Bechtel approval respecting this Firm, a formal appointment shall be made by executing an engineering services agreement.
Engineering Services Sub Contractor hereinafter called ‘Firm’
b) The scope of the Firm shall include but not be limited to carrying out the following engineering services’ operations for all buildings included within Process Buildings Package
Undertaking additional surveys, intrusive surveys and investigations as may be necessary for the engineering designs. Soil Investigations as required accomplishing the design
(Topographic survey shall be performed by AJES)
Production of all architectural, structural & allied services schematic designs
Perform all studies, design calculations etc.
Secure all governmental and local Authority permits and approvals if so necessary Compilation of any outstanding data deemed necessary for the completion of the detailed engineering design
Compilation of any outstanding data deemed necessary for the completion of the detailed engineering design
Production of all architectural & structural detailed designs for Bechtel approval according to contract & sub contract requirement.
Act as AJES Design & Engineering representative for the relevant Buildings contract scope
Civil & Architectural scope from its inception to completion as & when required
c) Building services : conceptual drawings only for plumbing & sanitary, small power & lighting, HVAC, Fire Fighting & Fire & Gas Detection/Loss prevention, Structured Cabling System
Liaison, co-ordinate & lead AJES services subcontractors’ design & engineering efforts
(AJES services subcontractors shall be responsible for the detailed designs and engineering for their relevant scope based on the conceptual drawings and other basic documents issued by Firm) to obtain necessarily approvals from Bechtel
Firm shall issue its whole drawings / documents production schedule immediately after the award & commence its design work keeping in line to the programme
Represent AJES at Bechtel offices / officials at UK, Abu Dhabi and / or Habshan as AJES’s Design & Engineering representative during the course of the contract from its inception to completion as & when required
Engineering coordination with the Firm shall be conducted from AJES head office. All field interfaces shall be conducted from site offices in collaboration with AJES field engineers
All other remaining functional descriptions shall be conducted by AJES personnel both in the head office as well as on site office depending on function wise technical nature
All engineering design products shall be managed conforming international standards included on the contract documents for the technicalities as well as document controls.
Firm shall comply with the agreed documentation system & conduct its operation in all respects accordingly. All the design documents shall be given appropriate numbering reference to meet traceability requirement. AJES operates its own system of centralized document control, which shall be used fully complying in accordance to Bechtel & Client Company Procedures by reformation, if so required
Firm shall produce & issue the scheduled documents at various stages of works for reviewing, approval & AFC etc efficiently keeping in line with the project construction plan on various phases. Any delay on this account shall not be acceptable to AJES management
Immediately, after the issue of the control documents to the site team, field/design engineers shall conduct over review of design & construction ability & consequently relevant design engineer raise technical queries to remedy any discrepancies among these documents if so discovered, which should immediately be resolved by the Firm & duly informed to Bechtel. All such documents shall be processed through the documentation system facilitating most convenient trace ability for consultancy & reference
Consequent upon the resolution of discrepancies, the effected design drawings shall be revised & reissued for construction duly incorporated with the solutions & circulated through documents control regularly to all concerned personnel.
Buildings services schematic drawings shall be issued to sub contractors for further development of shop & working drawings for Bechtel approval & issued to the concerned parties after getting duly approved for construction
Necessary structural shop drawings shall be produced by AJES own engineering personnel in head as well as on site offices, which shall also be processed into document control system for Bechtel & issued to the concerned parties after getting duly approved for construction
Preparation of requisitions for enquiry and award, technically evaluate bids and review of vendor / lower tier subcontractor documentation shall be done by purchase manager in collaboration with project manager. All these procedures have been incorporated on the company procurement procedures document.
d) Detailed Engineering Design:
Preparation, issue and control of calculations, specifications, drawings, material requisitions and bills of material. Extent of computer application for these activities. At the very first stage of the commencement of the detailed designs, Firm shall formulate positioning of all framing members vertically & horizontally befitting coordinates as well as level controls, meeting the architectural requirement maintaining the basic design principles that the whole structural skeleton behaves as an integral unit with its centre of gravity passing through or within the permissible vicinity of the resultant of all the applied forces considered avoiding any eccentricity and that settlement of the soil is within permissible limits. After considering all direct & indirect imposed loadings according to the relevant codes, design model shall be generated using Firm software. Loadings shall include, direct loads such as dead load, live load, seismic shear (though not applicable in Abu Dhabi geographical location) / wind load, blast load / effect, test load/application & also considering various analysis, a most critical case of resulting stresses shall be considered to be adopted for the dimensioning & further details of various vertical & horizontal members forming the framing skeleton. Generated model in 3D may be made available for the presentation to Bechtel & Company to explain & justify the adopted philosophy if so required. Calculations shall be done trying various options of loadings in 2D & 3 D & included with the design proposal for approval. These calculations shall be done & certified by a Chartered Engineer of Firm for structural adequacy & structural intended performance.
e) Services Designs
Designs of the services shall be carried out discipline wise.
Electrical - In accordance to the provision of electrical loadings design criteria as indicated on the Bechtel/Company documents, loadings, distribution of loading & all other parameters shall be adopted & calculated adhering to the international standards, IEE as well as UAE authorities regulations & schematic drawings produced meeting the architectural schematic drawings requirement
Similarly all loads from the HVAC disciplines as well as from the other remaining disciplines shall be included. This shall be done in close interface with all disciplines coordinated by the Services design coordinator / Design Project Engineer or Manager. All these details shall be included on the drawings documents for approval
All designs shall be generated using appropriate computer software package
f) Specialised discipline- Loss Prevention & others
On the similar pattern as described in the foregoing, detailed designs shall be calculated meeting all requirements of the contract specification, disciplinary performance as well as meeting international & conventional standards, complying local bodies statutory provisions.
From the foregoing approved documents, Bill of Quantities shall be generated discipline wise & building wise which document should be utilised for the purpose of Material Approval Proposal, Issue of requisitions of the approved materials to the procurement manager. The bill of quantities shall not constitute part of contract documents but serve guidance. All bills shall be generated using appropriate computer software package.
g) Specifications / Supplement Specifications
It is intended to adhere to Company specifications provided by Bechtel within the documents to every extent possible, however, to meet some particular requirement, supplement specifications shall be drawn & proposed for approval wherever necessary for producing better product or the materials for which no specification is defined. These shall be drawn in collaboration with Firm & AJES design team keeping in view an overall approach to documented specification criteria as well as conventional engineering & construction practice in similar circumstances.
h) Co-ordination Procedure
The following entitled co-ordinations shall be conducted during various stages of the design & execution that have been outlined below
Coordination between AJES & Bechtel head office
This part shall be conducted by regular interaction among AJES representatives Head Office based in Musaffa & Bechtel UK office to help resolve all pre & post award issue of Engineering services & monitoring project controls
Coordination between AJES & Bechtel site office
This part shall be conducted by regular interaction among AJES & Bechtel site representatives to help resolve all pre & post award issue of Engineering services & monitoring project controls
Coordination between AJES & Firm
This part shall be conducted by frequent interaction between AJES & Firm representatives of all disciplines for the resolution of all designs issues, issue of all documents, approval of all documents & resolution of all engineering issues on site
Coordination between AJES / Firm & Bechtel
This shall resolve all issues respecting engineering designs particularly during design stage as well as generally during construction phases for efficient decisions making to help smooth execution of all activities
Coordination between AJES / Firm & Bechtel on site
This shall resolve all issues respecting engineering designs during construction phases on site for efficient decisions making to help smooth execution of involved activities
Coordination between AJES Site & Firm
This is essential to keep on fast track the availability of complete design information for all ongoing as well as planned activities & should the information be pending, it shall be identified, coordinated & made available on site prior to its requirement to avoid any problem of execution
AJES internal Coordination among various sections
AJES in Head office organized with all corporate sections necessary to meet the requirement of this project shall operate as an integral functional team keeping on resolving regularly & as required all issues of project designs & follow up in all respects. This coordination is ongoing on daily basis & frequent interaction among all corporate managers as well as supporting professionals help the resolutions of all current & forthcoming issues. Management meetings are conducted regularly for making decisions to avoid any pending identified problems
AJES internal Coordination among various sections on site
Similarly on site all project sections managers & supporting professionals shall coordinate to resolve all types of problems to avoid any pending identified problems & notify to corporate management for immediate resolutions should the solution not be possible from site.
i) Review and Approval of Documents
This requires effecting an instant action on the part of AJES that, whenever any document is received, it must be reviewed by its design team located at Head Office/Site office as the case may be prior to formally submitting to Bechtel. After its submission to Bechtel, Bechtel shall process it through its system & after obtaining company approval, return approved or commented original to AJES for further necessary AJES action. All documentation shall be carried out adhering to the AJES documentation system after tuning that in line to Bechtel & Company requirement
j) CAD Procedure
It is intended to use standard CAD software for the production of design & drawings. All standard system of designing shall be adopted at every workstation available in Firm offices. The details of all available software & hardware have been given in attachment. Also included the hardware & software details which are functional in proposed Engineering sub contractor/Firm office
k) Engineering Reporting and Change Control
The status of design progress shall be submitted to Bechtel on a weekly basis during progress meeting. Should any change be required, that shall be affirmatively considered subject to cost impact resolution & then the change incorporation request issued by AJES to Firm. The Firm shall then work on the revision, its calculations & advise to AJES & Bechtel of any adverse effect on the structural adequacy / performance or if any amendment to be applied to already worked element / member. Should there be no such adverse consideration, the design shall be revised & revised document issued following the documentation & approval procedures.
l) Document Control Procedure
AJES operates its centralized DCC in head office that shall be tuned to Bechtel / Company documentation system & extended to site office to meet the project requirement. AJES document control system is enclosed for reference.
m) Vendor Print Numbering, Review and Distribution Procedure
All vendors shall be issued schedule of document numbers to be printed on the documents adequately in advance of documents preparation. All approved procedures of documents shall also apply to vendors' designs.
n) As-built Drawings
As built drawings serve the purpose of telling the user about the building records that should be used for the purpose of maintenance / or for whatever purpose possible. It is therefore, an important & significant part of documentation as well as also a contractual obligation on the part of AJES & Bechtel which should be affected smoothly & regularly throughout the duration of project. Should there be no change on the Released for construction drawings i.e. the construction has been carried out all in accordance with the approved documents provisions, there shall be no purpose of As - built drawings. But in practice, to produce physical structures, some changes are imminent due to arising of new requirement, changes, effects of disciplinary interfaces to bring the work to proper use functions etc. During the whole currency of the contract, it should be an endeavour of the AJES that all changes are recorded on contract documents as Red Lines mark up & issued to Bechtel for approval. These Red Lines mark up shall form the basis of producing all As Built documents on the project. It is not the drawings only that are to be recorded but also all changes whatsoever for any document on record. All these As Built shall form part of hand over dossiers. Should as built records be maintained regularly, this part of the dossiers shall be comfortably produced. The site design engineers shall keep an eye on this activity & record changes regularly as red line mark up & process the documentation to fulfil the contractual obligation to this extent possible. It is expected of the site engineers, the design engineers as well as land surveyors to coordinate on site to comply with this obligation efficiently. All survey changes or variations shall also be recorded on the drawings based on the pre pour & post pour records taken from survey section. Surveyor shall present all such changes on the corresponding documents to be recorded as Red Line Mark ups.
Inspection & Test Plans
All necessary Inspection & Test Plans shall be originated by the Quality Engineer in collaboration with Engineering in head office & Engineering in site team. These ITPs formats shall be issued for Bechtel & Company approval according to the procedures laid down on Project Quality plan. Production of all these documents shall be the responsibility of AJES Quality Manager / Engineer. Complete details about the quality management system have been included on the respective Quality Procedures document. Generally, ITPs for all disciplinary activities shall be produced for Bechtel & Company approval from site office in due course. All defined tests shall be conducted by Bechtel/Company approved laboratory located on site. For those items the tests shall be conducted by any Bechtel / Company nominated laboratory, for which facilities are not available on site. The details of these plans shall be submitted separately. Every ITP shall be allotted a document number along with a numbered checklist. Check list shall form the basis of inspection requirements.
Project Controls
Project Control management requires the formation of strategies those can be utilized optimally to achieve the target in minimum cost with best quality product
To achieve as aforesaid, it is extremely important that complete project should be analyzed from whole to one & all necessary resources to be used should be known prior to commencement of physical works.
Based on the project design, construction, commissioning and maintenance durations, Analysis, planning & charting out at various levels shall be carried out by the Planning Engineer. Further based on these periods, all necessary resources shall be arranged & mobilized by human resources, materials, and technical managers in collaboration with Project Manager.
The plans shall be monitored regularly, as the project construction progresses, on a weekly basis, monthly bases & no delay allowed & if any, immediate recovery shall be planed. The relevant reporting shall project the real quantum of planned & actual physical works, resources available, deficiency of resources, material procurement status, materials delivered & expected time of arrival etc & all necessary measures required to keep the construction on line & valuation worked accordingly. Every effort should be made to keep the progress in line with plan.
Procurement
Note-The term Material herein includes equipment also
According to the site requirement & provisions made on the plan, for temporary materials & consumables, requisitions shall be raised from site by the relevant engineer, checked, numbered & coded by the material controller & approved by the construction manager for transmission to head office procurement manager for further action. Cost controller shall further check the budgetary provision applicable & give clearance to the purchase manager for procurement. Purchase manager shall then invite the inquiries from various sources of material, negotiate & prepare a comparative statement & based on the merits of responses / quotations, record his comments based on the comparative statement as well as recommendations for the considerations by the Management. After reviewing the proposal, the management shall approve or reject the proposal. Purchase order shall be made on the approved proposal. An alternative source shall be located for the rejected proposal. A copy of the approval shall be provided to the project manager for follow up the delivery.
For permanent works, proposed material shall be submitted for Bechtel/Company approval on requisite Material Approval request form along with brochures, samples if applicable, processed through the document centre after Project manager approval. After obtaining Bechtel / Company approval on the request, procurement manager shall process the requisitioned approved item based on the budget quantities following in line the procedures applicable for temporary materials.
After the material is delivered to site, material controller & relevant engineer shall check the quality & quantity of the delivery. Any deficiency in quantity, quality or any damage observed, shall immediately be notified to the procurement manager through construction manager. Delivery information shall be circulated to the concerned personnel & quality manager himself shall or delegate an inspector or the relevant inspector shall check the adequacy of quality & if necessary according to ITP provision, shall invite the Bechtel/Company engineer to inspect / examine the delivery. The selected samples of delivered materials shall be sent to an approved laboratory for technical tests for the purpose of certification of compliance. After inspections & approvals, delivered materials shall be recorded in stores receipt documents, an issue to site may be undertaken thereafter.
Post placement of purchase order, Procurement Manager shall track various stages of material production & transportation or shipment to the site/delivery & if so noticed that an expectation exists for the delay in delivery, shall apply all efforts to expedite the delivery on appointed date.
Materials shall be stored in proper designated areas complying with the manufacturer’s instructions. Separate area shall be located for the materials requiring certain temperature of storage. Stores shall be well constructed & shaded. Generally, all consumables shall be stored in shade provided with proper lock & key arrangement. Materials which remain unaffected by exposition to weather may be stored open duly protected under proper watch & ward.
Proper protection shall be made for all stored materials inside covered area or out side. Necessary protection by removable membranes such as polythene or tarpaulins shall be used to protect material from the ingress of moistures or from effect of dust.
Storage of all materials delivered shall be done complying to the set & approved procedures making sure that all inventories can be verified any time & that any material can be traced any time easily.
All entries of the incoming deliveries shall be recorded into the register & verified by the store keeper & material controller that it complies with the details on deliveries documents. Any deficiency noticed shall be immediately reported to the procurement manager.
After the acceptance of the material by the concerned authority only, a store issue shall be affected & recorded on the required issue documentation. Regularly the status of all receipts, issues & balance in stores shall be reported to the construction & project manager who shall act further depending on the project requirement.
Elaborate details have been given on the AJES procurement procedures document
International and local transportation and customs clearance
Materials & equipment that have to be imported from overseas, shall also follow the foregoing procedures with the addition that necessary Letter of credits shall be opened by AJES adequately in advance of the required date of delivery adhering to schedule date, so that the delivery is shipped in time from original source. AJES procurement manager shall arrange all port clearances immediately of shipment arrival & material shipped to work site. Tests & Examinations shall be conducted similarly as aforesaid. Any claims of insurances for the damaged material shall be made immediately after inspections. Process to replace the damaged material shall be carried out at once to avoid any delay. If so required, AJES shall apply in time for any statutory road permit for the efficient transportation of the material by suitable vehicles. Elaborate details have been given on the AJES procurement procedures document.
Procurement and provision of construction spares, commissioning spares, insurance spares and special tools
These shall be processed applying the same methods of procurement & delivery received by AJES / its services or specialist sub contractors. Most probably, the spares shall form part of the order package. Elaborate details have been given on the AJES procurement procedures document
Recommendation for two-year operating spares for approval by Company in accordance with the G-SPIR format requirements
This provision shall be followed & spares delivered according to contract & Company requirement by AJES / its services sub contractors. Elaborate details have been given on the AJES procurement procedures document
Procurement and provision of two-years operating spares, (at cost and extra over Lump Sum Subcontract Price)
Similarly this provision shall be effected & spares delivered according to Bechtel/Company instruction to AJES subject to the approval of the procurement cost prior to the purchase order placement by AJES
Source inspection
If so required by Bechtel / Company, arrangement shall be made by AJES after meeting with the vendor or manufacturer, a date & time appointed for the inspection to the convenience of all parties concerned & required inspection at source conducted to the satisfaction of Bechtel or Company. Representatives from Bechtel and/or Company, AJES, services sub contractor & vendor shall constitute an inspection at source team. Proper record of inspection shall be made.
Compliance with Company’s criteria and procedures for selection of vendors including but not limited to compliance with local registration requirements and approval of purchase requisitions, bidders lists, technical bid summaries and award recommendations
We shall adhere to Company requirements.
Involvement by the UAE in particular and GCC in general with respect to the provision of local materials and services shall be encouraged
AJES honor & respect with due regards to the provisions of UAE & GCC policies for the materials & professional services which need be availed out of the local & GCC sources subject to the compliance with the quality requirement. Every effort shall be attempted by Procurement Manager to chart out the available ‘local & GCC sources’ & prepare a database to be used whenever any applicable procurement arises. This procedure is already followed by AJES. AJES vendors shall also comply with this requirement.
Pre Mobilization Planning
A thorough and logical mobilization plan is essential for the successful start-up of construction activities. This plan must detail all planning, preparation and pre-construction activities necessary to ensure the timely availability of drawings, personnel, construction equipment, temporary facilities and materials at the job site to properly support the construction efforts.
This plan is already under preparation at this stage.
This preliminary mobilization plan shall be further developed after contract award and concluded within a week of the contract award. The mobilization plan shall be closely coordinated with the construction plan to ensure mobilization activities properly lead into and provide a smooth transition into initial construction activities.
A time scale bar chart diagram shall be prepared with early and late activity bars detailing the main activities to achieve full mobilization of staff, labour, construction equipment and camp/site facilities shall be prepared at the commencement of the contract.
Mobilization plans for staff & labour, accommodation and temporary facilities established during the bid stage (as conceived in pre-mobilization planning) would be studied and re-evaluated in the light of any changes, which may have occurred since the day of preparation. All necessary adjustment measures shall be implemented.
Additional site visits shall be conducted immediately after the project kick off to confirm data collected during bidding stage, reconfirm assumptions and establish additional information required to permit smooth and timely mobilization. The following items shall be reviewed and confirmed.
Access to the job site
Locations of temporary facilities
Company requirements for properly validated licenses and certificates to be held by construction personnel
Transport plans
Loss prevention and safety requirements
Arrangements for first-aid facilities
Arrangements for drinking water and construction water
Arrangements for electricity supply
Arrangements for storage fuels and lubricants
Arrangements for sanitary & its disposal facilities
Final arrangements for security interface with Bechtel & Company
Work Centres Ajes Head Office
Upon notification of contract award, the key personnel to the site Management Team shall be assigned. Construction personnel shall be mobilized to the project site office to provide input and direction to the project team. Successful project execution requires construction experts to be active from the onset of the project. The only activity to continue from Head Office after mobilization period is procurement. All procurement for the project shall be done from the corporate procurement section located in AJES Head Office at Mussaffa, Abu Dhabi.
The following specific activities must be addressed early to be fully effective:
Finalize construction schedule requirements and subsequent approval from Contractor
Review manpower requirements for both non-manual and manual personnel; update these requirements by means of staffing schedules, histograms and craft mixes; and ensure subcontractors manning levels are compatible.
Review construction equipment needs and ensure that timely subcontractors mobilization plans are in place.
Review field procedures and method statements defining standards, policies and procedures required for the execution of the works and ensure they constitute “Project Specific” status.
Review environmental, safety and Health (ES&H) and site security plans to ensure compliance with the client’s specifications and guidelines.
Review Construction Quality plan in line with the guidelines of ISO 9000 and check Established QC parameters by discipline.
Overview temporary facility requirements, including indirects such as tools, consumables, gases and the like and check subcontractors compliance.
Actively pursue preliminary site activities such as approvals, permits, establishing contracts.
Ensure Lessons Learned & Practices from previous projects are well understood & should be applied effectively from the onset of the works itself to achieve professional products.
AJES Site Office
Actual ‘on site management’ would be from offices based on the site next to Contractor and Company’s office. AJES Site Office is fully supported by AJES Head Office at Musaffa.
The following major activities shall be carried out at site offices.
Safety Regulation Enforcement
Quality Assurance Enforcement and Procedures
Construction Method Statements
Construction Planning
Site Documents Control
Field Engineering & Design Controls
Material Requisitions
Materials Control and Tracking
Materials Storage
Work Procedures
Physical Construction
Site Administration
Mobilization
Mobilization shall be coordinated from the AJES Head Office at Abu Dhabi with input from AJES personnel already mobilized for the execution of Site Preparation Package and Temporary Facilities for Contractor and Company. Existing teams responsible for the execution of the those two mentioned packages already have substantial cadre of experienced professional well versed in mobilization of temporary facilities, project execution, QA / QC planning, Safety and security operations etc.
Mobilization shall commence with the following activities:
Kick off meeting to commence the sub contract
Commencement of the required land surveys to establish various horizontal & vertical controls bench marks
Incept of the engineering designs at the Firm office
Soil Investigation by an approved laboratory
Construction of temporary facilities
Obtaining various permits from Authorities and conclusion of arrangements with local committees where necessary.
Third party independent concrete testing laboratory credentials submission for approval.
Shortly after contract award, site surveying shall begin utilizing the Total Station System to establish accurate control points for the performance of the work.
As soon as practicable, the plans and specification for the site temporary construction facilities shall be finalized and released for installation.
During the installation of the temporary facilities existing AJES site offices shall be utilized to supervise the site activities required for the temporary facilities installation.
On completion of the site offices at Habshan, balance of the AJES construction staff shall be mobilized to the site along with construction equipment, tools, consumables, warehousing, storage and other items necessary to commence the work in accordance with the construction schedule. Temporary facilities at the job site shall include Generator Yard and Construction water storage tank, carpentry yard, re-bar fabrication, lay-down area, warehouse and workshop facilities at location A4.
At the start of the construction, an emphasis shall be given on the critical requirements of the construction schedule. Work shall be carried out under continual supervision and inspection over performance. Progress shall be monitored on the basis of actual installed quantities compared to scheduled quantities.
For construction areas, dedicated work crews shall be allocated for each discipline supervised by foremen and general foremen who in turn shall report to the discipline supervisors / site engineers. Based on the construction schedule requirements, necessary operational crews shall be formed and controlled over to meet the planned progress target to be physically achieved satisfactorily.
It is the responsibility of the supervisor / site engineer to ensure the efficient utilization of his material, workforce, tools and equipment.
For ‘construction operation water’ requirement, unless an alternative arrangement is made available, water shall be trucked from nearby Desalination plant.
Site ‘construction and temporary facilities electricity requirements’ shall be met by installing suitable size and suitable numbers of generators.
Subcontract Strategy
Building Engineering services shall be utilized by appointing a consulting firm, to be responsible for the complete architectural, structural design drawings & documents productions as well as for the services schematic designs drawings production. Firm shall also represent AJES regularly during the project currency
Detailed services designs shall be prepared by AJES services sub contractors
AJES shall carry out broadly all civil engineering works employing its own resources of manpower, machines, equipment etc.
Lower tier sub contracts shall be allowed for the execution of single operations such as supply of ready mix concrete, roofing finishes etc
Ready Mixed Concrete is envisaged supplied from an established RMC supplier, an establishment with proven track record duly approved for supplying concrete by GASCO, within 10 kms of the site. However, in the mean time, without reservations, we are also seriously considering installing our own concrete batching plant.
In case any minor or specialized work is necessary to be sub contracted on lower tier, Company procedures shall be apply for prequalification and award of the subcontracts.
Testing And Inspection
A field inspection and testing program shall be organized to be in line with AJES Quality manual & Approved Project plan under overall responsibility of the QA / QC Manager.
Prior to conduct any testing, Contractor and Company (as required by QC Plan and ITP) shall be advised of the tests for witness.
Wherever required vendor specialist shall be made available for conduct of testing and inspections.
Material Management
Once material has arrived at site, material management shall come under the purview and custody of the site store staff. The storekeeper, supported by his store assistant shall be responsible for the custody of the material prior to issue. Material tracking from source to the place of installation shall be conducted by the computerized system. The construction manager shall be responsible to provide the technical oversight and direction for the control of materials at the construction site area. More information has already been elaborated in the foregoing.
Procurement
The Central procurement department located at the Al Jaber Energy Services, Musafa, Abu Dhabi, UAE office shall be responsible for all purchases adhering to the following procedure.
Preparation of Purchase Requisition shall be made based on take-offs quantities calculated from the approved drawings documents. Purchase requisition shall completely, identify all applicable drawings, data sheets, specifications, vendor documentation requirements etc. with the inclusion of following information.
Quantity of each item required with comprehensive breakdown
Adequate information concerning nomenclature description, Material approvals, Quality required, applicable specifications, design & other drawings, etc / or detailed outline of the material required.
Required delivery dates for all major items.
Delivery points of major items
Inspection of the goods at the point of origin issue
Certification of test data and/or compliance / warranty
Method of shipment (if goods imported), conditions/packing
Instruction of holding, kitting consolidation, marking
Drawings, manuals etc
Spare parts requirements
Special Instructions to vendors
A technical evaluation shall be done in house to verify the conformity with specifications.
Samples and technical information shall be submitted to Contractor. Once the final approval from the client is obtained, purchase order shall be raised.
Upon receipt of Purchase Requisition, a purchase order shall be raised and entered in the computer register system, indicating cost and budget allocation.
The procurement department shall maintain a follow-up system so that contact suppliers and / or manufactures may be made on continuous basis.
All questionable delivery commitments shall be expedited on a daily, weekly and monthly basis as required to ensure prompt delivery in accordance with the requirements.
Organization Corporate Organization
Al Jaber Establishment formally known as Al Jaber transport & General Contracting Establishment is an umbrella organization which has got numerous divisions within in itself and which is also the parent company for various subsidiaries. Al Jaber Energy Services (AJES) is a separately registered company specifically set-up to target the energy sectors and its clients. AJES has been operating under the Al Jaber Establishment umbrella since 1995.
Broadly all the activities of the above divisions and companies can be divided into:
General Construction
Heavy Lifting and Transport Services.
Trading
Industrial
Plant Construction.
Site Organization
Proposed site organisation and responsibilities of the key personnel are enclosed. All supervisory staff shall be highly experienced and qualified drawn from on-going projects wherever possible.
Manpower Resourcing And Mobilization
All the personnel on site shall be employees of Al Jaber Energy Services. All of the required personnel to execute the work are already in UAE and working on other sites. These sites are due for demobilisation in the coming months.
The planning department shall produce a histogram schedule of the resources by category. These schedules shall define the monthly manpower levels. The scheduled shall also be indicative of manpower mobilization.
The standard Al Jaber Energy Services site supervision is based upon the principle of training. A charge hand shall be trained and supervised by a foreman. In normal cases a foreman shall supervise four charge hands. The charge hand shall then supervise approximately ten labours. Where a special process is conducted, this ratio may be revised accordingly.
Training is a requirement of the Al Jaber Energy Services quality management system and foreman and charge hands shall conduct training of the manpower in their respective roles and functions. The recruitment of manpower shall ensure that background in the relevant job skill has been achieved. The training in quality awareness shall be an ongoing process through the quality department and the foreman.
Sufficient numbers of site supporting staffs which consists of Mechanics, Electricians, Auto Electricians, Guards, Water boys etc and other ancillary staff shall be deployed for the unhindered progress of the work.
The Al Jaber Group contains at all times a vast pool of manpower in all Disciplines. These workforces are at all times working on various projects in multi discipline fields.
Equipment Resourcing And Mobilization
Based on the project schedule the planning department shall generate the construction equipment schedules.
The Al Jaber Group is one of the largest equipment rental companies in the GCC with over 5000 fleet where modern repair and machine facilities enable them to maintain a first class fleet of equipment.
It has been our company policy to weed out the old equipment on a periodical basis and keep the equipment fleet very young. We have one of the youngest fleets of equipment in the GCC based on size.
Construction Method Statement– Process Buildings
Following the award of the project, a detailed contract scope works programme for the whole project shall be developed including all disciplines separately based on already approved outline preliminary programme appended under the coordination of our Construction Manager and Planning Engineer
The Method Statements related to various project activities shall be submitted for contractor’s approval prior to commencement of any activity during the execution stage.
Subcontracting
Develop and manage a lower tier subcontracting plan and subcontractor list AJES plans to carry out most of the civil activities itself but selected items shall be sub contracted on the lower tier such as ready mix concrete, roofing application, doors & windows manufacturing, painting application, raised flooring application, suspended ceiling installation etc.
Perform all lower tier subcontracting activities including specification of packages of Work to be subcontracted, pre-qualification of bidders, issue of ITBs, bid evaluation, recommendation and award. All relevant information shall be provided by the Project Manager to the purchase manager who should act immediately to conduct the required functions & the lower tier deal finalized after obtaining Company recommendation by the Project manager
a) Management of lower tier subcontractors and their activities
These operations shall be manager & controlled by the Construction Manager on site & reported to the Project manager
Monitoring and reporting of all lower tier-subcontracting activities. This activity shall be affected by the project manager based on the construction manager report. The report shall be regularly provided to the planning engineer, head office & Company.
Involvement by the UAE in particular and GCC in general with respect to the provision of local services shall be encouraged. As included earlier somewhere else that UAE national policy shall fully be honored subject to making no compromise to the quality requirement
Construction including providing labour, supervision, safety and quality management, inspection, vendor support, temporary facilities and services, and construction equipment, tools, utilities and consumables. All these issues have been elaborated earlier somewhere else
b) Provision of Construction Camp, messing, transport to Jobsite, sanitation, utilities etc. for SUBCONTRACTOR’s personnel.
All these shall be fully undertaken by AJES based on the site requirement. Already a camp exists on site & further extension shall be made to meet the contract requirement. Messing shall be resolved by employing catering sub contractors so that all personnel & workers take good food. All utilities shall be provided to maintain the good house keeping of the camp. All safety & emergency precautionary measures shall be undertaken to the contract requirement. AJES operates its own system of transport, which shall be extended for the use of workers transportation. Similarly, the arrangements shall be made for the employed high tier & low tier sub contractors on this package
All activities necessary for Mechanical Completion, Pre commissioning, commissioning, and Provisional Acceptance.
All activities for the buildings part have been described on the method statement appended
All testing facilities required at Jobsite
AJES shall supply an independent testing laboratory equipped with all equipment necessary for involved tests for this package properly managed by qualified personnel meeting all QA testing & certification requirement.
AJES aggress to extend its full cooperation to meet any Third Party Inspections. Project manager & Construction manager shall be responsible to affect this part of the contract.
Supply and coordination of lower tier subcontractor and vendor representatives as necessary
AJES shall supply & coordinate with all lower tier sub contractors & vendors or their respective representatives to the requirement. Supply of these shall be managed by the Purchase Manager while the Project manager shall manage on site. Coordination shall be conducted by the Construction Manager
Provision of waste management at all Jobsite locations, including disinvestments of all temporary works, upon completion of Work
Waste management shall be fully operational on a day to day basis both for garbage & sewage according to the planned arrangements. Safety manager shall be responsible for the operations of all such activities & report to the Construction/Project Manager regularly
Provision of medical and fire-fighting services at Jobsite and for temporary works
Medical male nurse shall be employed on job site First Aid centre. Male nurse shall take care of providing First Aid treatment to injured workmen immediately & then the worker if so necessary in the opinion of the male nurse, shall be sent to Contractor site clinic for further treatment. Safety manager shall be responsible for the operations of all such activities & report to the Construction/Project Manager regularly
SPECIFIC CONSTRUCTION METHOD STATEMENT– BUILDINGS PACKAGE
It is known from the contract documents that 15 buildings for various intending use as Sub station+Bottle Store, New Control Building, Instrument Equipment Shelter+Bottle Store and Operator Shelter have been defined to be constructed
Keeping in view the nature of contract being EPC, AJES have decided to apply RCC in situ construction for all intended buildings accepting the Company direction on drawings for which a confirmation was communicated to Company on May 7, 2005. RCC framings shall meet the design criteria of blast resistant & resilient structure productions meaningfully. Sub Structurse shall also be constructed of RCC in situ.
Soil report bore holes log direct to employing spread footings in isolation, which shall be integrated by grade beams/walls to form an unit for compaction settlement & long-term consolidation controls. However, to verify the validity of the soil report, AJES shall further conduct investigations based on the Engineering Services sub contracting firm recommendations, utilizing the services of an approved laboratory. Foundations shall be designed based on the laboratory recommendations.
The phases of the construction shall be adhered to meeting the set out milestones, which are very tight for the purpose of physically executing the buildings package. The construction teams shall be constituted to meet the requirement as exhibited on the organization chart. One project site manager shall be an overall responsible for all on site execution operations & conduct interface with the head office duly supported by safety, construction, quality, technical & administration sections all to be well established on site. Project & Construction manager shall in collaboration constitute six independent dedicated teams for six working divisions/areas lead by each site engineer directly reporting to construction manager as shown on the organization chart. Each team shall comprise of one site engineer, required number of site foreman & further supported by charge hand from each trade. For each team one quality assurance/control engineer shall be deployed to conduct QA / QC procedures for the relevant area. One General foreman shall be deployed for the labour engagement responsibilities on various day-to-day activities. For all other organization details please refer to Project organization plan.
A surveying team shall be constituted lead by a chief / senior surveyor to carry out all site setting works from the stage of preliminary site survey to the point of recording redlines for the purpose of ‘as built’. Survey team shall coordinate with each site engineer to meet site requirement. It shall be the responsibility of each team to set out, inspect & record all layouts, pre & post concrete data for the purpose of approval & handover dossiers. All horizontal & vertical controls shall be established & monitored by the leader.
All approved controlled drawings shall be issued to surveying team to commence the setting out operations. After ensuring proper safety arrangements are in, survey barricading shall be established & necessary grids control fixed & inspected by QA / QC. Excavation shall commence after the clearance is obtained & continue according to the plan. Proper safety shoring shall be arranged during this activity when it crosses 1.5 m depth & arrangement for suitable access into pit made to the satisfaction of the safety inspector & company. All unsuitable excavated material shall continuously be removed from site & suitable material tip off to designated area. All environment controls shall be taken care off during this operation. A surveyor shall continuously ensure the depth of excavation does not exceed the design requirement. When the excavation reaches the formation level, dressing shall be started followed by compaction of the soil so that area is ready for inspections.
AJES QA / QC shall inspect the formation. After required clearance, arrangement shall be made for blinding all released area according to the approved method statements. Area shall be blinded to the design thickness minimum 75 mm properly levelled & trowel applied to make it suitable for the purpose to receive heavy duty concrete protection layer membrane. Then curing shall be carried out for 3 days. Application of the protection membrane shall commence thereafter over whole area of the blinding.
Foundations shall be set out to design details to permit formwork erection & rebar placement. All starter rebar shall also be fixed supported by plastic spacer. On sides also plastic spacers shall be fixed to keep all rebar in proper position. Foundation top levels shall be fixed using 25 mm plastic triangular chamfers horizontally. Chamfer shall also be fixed on the vertical edges of the forms. Inspection shall be conducted followed by concrete pouring supplied by an approved ready mix plant. All ready mix record shall be maintained according to QA approved procedures. After concreting is finished, proper curing arrangements shall be made for the required number of specified days. Setting outs for further stub columns shall be done & preparatory works continued.
In parallel, all works regarding grade beams/walls shall continue complying with all the approved procedures. Fabrication of rebars shall be done in a designated area while fabrication of forms too in another designated area all according to approved procedures. After completing the preparatory works for the stub columns, inspections & pouring shall be carried out following all procedures. Operations of grade beams/walls shall be taken up on similar principle as other activities.
For sub stations where cable cellar floor slab is to be built, shall be prepared together with surrounding sub structures. After curing is done for the specified period, protection membrane shall be applied on both horizontal & vertical surfaces followed by inspection & backfill in compacted layers to specified requirement. Field density tests shall be conducted to monitor the requirement of density & water content etc. Backfill shall continue up to the formation level below the grade slabs blinding in buildings & where cellar suspended floor slab is to be built, backfill shall be done around the grade structures.
Preparations shall be carried out for the cellar suspended slabs by erecting required supporting system, forms fixed, rebars placed, all services inserts provided & inspections conducted from all disciplines followed by the concrete pouring observing all QA procedures.
Similarly, on the areas where grade slab is to be built, after the completion of the backfill up to the bottom of blinding concrete i.e. formation level, plastic sheet shall be laid after compaction & leveling & all necessary under ground services completion, blinding concrete shall be poured, leveled & wood floated well to make it sufficient enough to receive the grade slab. After three days of curing on blinding, preparation for the grade slab works shall commence & re-bars placed either by site fabrication or using pre fabricated mesh to design requirement. All necessary services shall be inserted, inspections conducted & concrete poured. At this stage of the building, major sub structural elements have been completed giving a way to commence the super structural works.
All preparatory works of superstructure elements shall come into full swing by the fabrication of the forms & steel rebar fabrication to the BBS details. Scaffolding shall be erected for the fixing & placing vertical rebars of columns & walls in all required areas. Steel rebars shall be fixed placed with spaces & inspections conducted. Any inserts necessary for the electrical conduit or earthing, shall be installed immediately & inspection conducted. Work of vertical forms shall commence for sides of columns as well as walls fixed using removable tie bolts with cones/boss at tie rod ends. Forms shall be made of fair face ply to produce specified texture to the elevation requirement. All exposed vertical edges shall be chamfered using plastic chamfer 25 x 25 mm triangular section nailed to the forms. Inspections shall be conducted for the elements ready for pouring. Pouring shall commence keeping the height of pour not more than 2 m using vertical pipe chute of the pump reaching up to necessary level. Curing shall follow adhering to the agreed or approved procedures. Similarly walls of transformer areas shall be built adhering to all QA procedures.
Next operation of erection of the propriety scaffolding to support the superstructure roof slab shall commence strictly complying with the scaffolding drawings. On parallel, operations of fabrication of forms & rebar shall be taken up. All vertical & grid controls shall be established by surveyor to keep in line & level all forms of beams alignment & soffits. Level of slab shall be established & then work of form fixing shall commence followed by placing of beams reinforcement. Services inserts such as electrical conduits, HVAC inserts or block outs if necessary & other inserts shall be marked for establishment. Works of steel rebar placement shall continue in parallel to speed up the preparatory works. An inspection of the preparatory works shall be conducted by all involved disciplines. After obtaining approval for the pour, pouring shall be carried out adhering to pouring method statement compliance. Curing shall be started immediately after finishing the surface as required by the curing compound manufacturer’s instruction for the application of compound & also by using water in combination all to agreed procedures.
Intermediate slabs on the Battery rooms shall be constructed following the foregoing procedure.
Erection of the scaffolding around shall extend to cover the parapet portion followed by formwork & rebar fixing. On the similar pattern as defined earlier, all inserts shall be fixed followed by all relevant inspections & pour. All aforesaid concreting operations shall be supported by necessary number of transit mixers, concrete pumps, nozzle vibrators conforming to perform 10000 oscillation per minute & all other necessary arrangements necessary to perform the best task. Well-trained teams shall be engaged for such operations. All necessary safety measures shall be installed. If necessary during hot weather, rest pauses shall be allowed to workers with the provision of liquid or salt water. Forms shall be struck form the elements carefully ensuring full safety intact. Concrete surface shall be inspected immediately after removing form, cleaned & surface treatment to the project specification applied to produce specified class of surface texture i.e. smooth finish or sandy or rough or grouted.
Any defective concrete shall be applied remedial measures as agreed with the Company or Client. On New Control Building, special forms shall be erected for dome portion, followed by the steel rebar fixing & pour. Wherever special openings have been provided in designs within the structural framing, those shall be provided within the formwork itself. Now the structural framing works have been completed giving way to attack on internal walls & other items such as dry wall lining & preparation for the roofing item. All preparations shall commence for the remaining works.
Block work shall be carried out wherever required for walls followed by services fix 1 items & then plastered over as specified.
Roofing shall commence by scabbling the slab surface, laying of light weight foam concrete in grade minimum % to receive water proofing membrane, membrane application followed by water leak test for 72 hours & then polystyrene boards laid over to be protected by concrete pavers. Seperation geotextile shall be provided according to applicator direction. Over concrete protection paint on parapet, Aluminum flashing shall be fixed to design details.
Services site team shall be inducted in full swing for carrying out all disciplinary operations.
Suspended ceiling fixers shall also enter in to commence the work. Where there is no ceiling, work on the slab finishes shall continue.
Wall lining work shall be carried out in accordance to design details after ensuring complete inspections of services conduits etc. are over.
Fixing of cable terminations framing steel as well as framing steel for the floor openings shall be carried out according to details.
Flooring shall be carried out in according to design details. Tiling shall be followed on required areas schedules to receive floor or wall tiles.
Concrete surfaces requiring protection shall be applied accordingly with 3 coat system or any other approved.
Operations of constructing transformer foundations shall be carried out & protection applied to that. Sums shall be constructed to details in floor. Gravel filling shall be done around the transformer oil containments/enclosures.
All finishing items shall be carried out in wet areas & concealed piping shall be carried out prior to that. Services operations shall be completed in all areas followed by finishing works. Services inspections shall be conducted prior to commence the finishing works.
When the works are ready involving the scope of telecommunication routes, an entry shall be allowed to the related other sub contractor from other scopes provided with full cooperation in all respects.
Similarly, car park shed shall be worked by constructing its foundations with anchor bolts inserts. The engineered structure shall be erected on the foundations.
Works for the planter beds shall also be completed accordingly to the plan requirement. Works of all ramps shall be constructed according to details.
Works of external services within 5 m of building shall be completed & tested. All surrounding or backfills shall be completed to the specification provisions. Walkways works shall commence by filling & leveling around the building excluding the instrumentation room on the plant side portions. Walkway Kerb shall be fixed to the profile over the blinding concrete with haunch concrete over. Sand shall be filled over the compacted & profiled area of the walkways whereon the interlocking concrete blocks are to be fixed in to design pattern.
Around new control building, work of embankment shall be carried out to the profile shown & back fill done in layers to retain the walkway. This embankment shall be used for grass growing. All internal & external light fixtures shall be installed. New control building requires complete furnishing excepting personal computers.
All furniture shall be procured, inspected & installed accordingly to the relevant details.
Necessary directional signs to be installed in buildings shall be fixed to approvals. All other furniture within scope shall be inspected & installed accordingly.
Foundation works for a 100 m mast to support radio antenna shall be carried out at New Control Building which activities include setting out, excavation, blinding, rcc block, concrete protection.
External landscape items such as gravel spreading, grass growing shall be undertaken accoding to layout shown on drawing.
Pre commissioning, Commissioning, Provisional Acceptance and Final Acceptance All services individual items integrity & tests shall be conducted by related sub contractors & record maintained. After ensuring that each installation is efficient in performance, release for commissioning shall be given. Details are included within the technical literature/datasheet
Supply and coordination of lower tier subcontractor and vendor representatives as necessary All necessary lowers tier sub contractor & vendor representatives shall be provided to the scope requirement
All activities necessary to achieve Pre commissioning, commissioning and Provisional Acceptance. Services disciplines such as electrical, fire alarm, & gas detection system, fire suppression system, internal sanitary & drainage, infrastructure of all other included services require pre commissioning, commissioning & provisional acceptance. All fix 1 & fix 2 procedures shall be conducted according to ITPs & approved procedures.
All utilities, fuels, lubricants, chemicals and catalysts required up to issuance of the Provisional Acceptance Certificate. Within Contractor scope
All required operating and maintenance documentation. All operating & maintenance manuals shall be submitted covering work scope items
Warranty Obligations through to Final Acceptance SHALL be submitted for the work scope items
For further details on the services method statements for the package, please refer to the CCTC documentation (not attached within this proposal).
EXECUTION PLAN Method statement
(PROJECT IMPLEMENTATION STRATEGY)
Civil Works/Site Preparations
Construction Method Statements
Civil Works & site preparations shall be executed according to Company & Contractor requirement depending upon the priorities. It is expected that all the design & relevant details pertaining all involved structures shall be issued for construction by the Contractor in time according to the agreed schedule of construction. It is also expected that the site shall also be made available in time to meet the schedule requirement. It is proposed to commence the works from all available areas respecting which designs are available immediately after mobilization & upon the receipt of the ‘Permits to Work’ if so required. Areas belonging to the standalone scopes may also be taken upon one by one depending upon the Company priority.
Smooth execution of the construction works necessitates the organization of certain competent teams constituted of capable members fully trained in their respective callings. The team members should upon receipt of the project documents should not waste any day but immediately commence with the practical works with the resolutions of all technicalities issues. Surveyor should efficiently establish all setting outs & its controls with prompt approval according to the guidance of the site engineer. Site engineer in conjunction with the site management should arrange all equipment necessary for the smooth excavation & other following activities. It is also advised that feed back & homework planning has also been under charting process at the pre mobilization stage as envisaged somewhere else in this document.
Since our organization works adhering to the set standards of execution in compliance with the quality manual & the project quality plan, all our staffing level shall affirmatively follow the guidance & the direction provided to, optimally utilize for the discharge of their functional responsibilities entrusted by the management, for product quality assurance as well as customer satisfaction.
Our efforts shall be to organize the works in such a way that trained teams are established on site for important activities such as steel fixing, formwork, concreting, concrete protection etc. The team members shall be proficiently skilled in the respective trades & group shall be rotated on the project various locations in sequence to perform the jobs on various work elements following the guidance & direction of the trade foreman & general foreman, adhering to the instructions by the site engineer and/or construction manager. Quality team shall monitor fully these operations of the construction teams.
These teams shall be extended full technical & administrative support from the engineering as well as procurement & all other controllers based on site as well as in head office immediately, whenever required.
This document gives an overall strategy of proposed performance pertaining the site preparation & civil works keeping in view the quantities of various items/descriptions involved & the construction duration according to the defined milestones.
Company major policies have already been incorporated within the Execution plan of the New Buildings Package which is an EPC forming a part of overall subcontract scopes.
This document should be considered as an extension of that, since the main purpose herein is to serve on the communication of specifically significant procedures that may be adopted on the project based on our past experience of construct able competency which has been exhibited by outlining the procedures & definitions that should be adopted for the proficient prosecution/ execution respecting various preparatory works items involved on the project under works code groups entitling Site Preparations & Civil Works
The scope involves the sub titles & their description of constructions as follows, which cover major portions of the Preparation & Civil Works for the project.
Site protection & preparation- Surface levelling-Area for this activity shall be selected according to the scope indicated on the IFC drawings. Inspection of the available surface shall be done first visually & then ascertained by spot levelling & undulations noted. Undulation means certain types of ridges & valleys generally of irregular profile. Ridges shall be chipped out & filled into valleys to form a balance throughout the area under consideration. All unsuitable material shall be removed to the specified thickness using heavy equipment such as shovels or bulldozers & selected good material filled. Dressing of whole area shall be conducted to form an acceptable level line profile. Surface Compaction using water shall be carried out to maintain the required profile. Dry & wet compaction shall be carried out to a suitable state of acceptance. Similar procedure shall be applied to the sloping surfaces. Areas covered around obstacles for both flat as well as sloping shall be dressed manually & compacted by plate compactors or light rollers.
Checking procedure- Profile should be within acceptable limits. Soft spots should be removed.
The survey team shall locate and mark, all services that are present upon the site (This includes above ground services as well as buried services). These services, (Electric, telephone, gas, oil, chemical, water etc), shall be clearly marked using stakes and warning tapes. These existing services shall be marked upon a site drawing and the issues raised with the client for reaching a practical resolution.
The survey team shall also mark upon the site plan, all obstructions, structures and developments. Any obstruction encountered during excavation activities shall be plotted and recorded.
Site Preparation & Earthwork Typical
Where hazardous material is encountered, it shall be identified and isolated. Technip & client shall be informed. The hazardous material shall be collected and removed to a licensed tipping place. The details of the material and tipping arrangements shall be documented for review by the client as appropriate.
Wherever within the subcontract scope, existing structures, fences and developments, shall be demolished in a safe manner, as site-stripping activities proceed. The necessary permits, approvals and permission shall be obtained from the concerned authorities, prior to the commencement of the activity. The method of removal of these existing elements shall usually be conducted by dozer or breaker. Where necessary, discussions on site shall be conducted concerning alternate methods of removal, when the full extent of these structures is exposed.
The removal of the topsoil shall include all vegetation, and rubbish material, from the work site.
Prior to the start of topsoil removal, the surveyor shall peg out the haul roads that shall be used by the construction equipment for all the site preparation activities. These roads shall be constructed by levelling of the existing terrain. Grade pegs shall be set to an agreed grid, to indicate existing grade and reduced grade. Dependant upon the quality of the existing soil where the roads shall be built, suitable compactable fill may be imported or re-located from other parts of the site.
These roads shall be maintained as the work proceeds.
Where required water shall be spayed for dust control.
For general removal of the topsoil activities, using appropriate equipment, the areas concerned shall be excavated and graded to levels that shall ensure adequate surface water drainage. The Geotechnical Engineer shall monitor the activity, to ensure that the topsoil material is removed. Sampling and testing of the resultant material shall commence and be conducted for specification verification and compaction data.
Upon completion of the topsoil removal activities, where appropriate, the exposed surface shall be scarified, moistened and compacted, to achieve the required density criteria. The areas shall be divided into manageable sections that shall be defined upon sketches. The Geotechnical Engineer shall monitor and test all sections. The results of the tests shall be recorded upon the relevant QC format. The number of tests conducted shall reflect the specification requirement. QC Engineer shall monitor activities regularly.
In excavation areas, the Geotechnical Engineer shall review the material to be excavated, to ascertain its suitability for re-use as fill material. This excavated material shall be transported to areas that require filling. The material shall be deposited onto the areas to receive filling, levelled, moisture conditioned and compacted. If necessary, stockpiling may be required.
The excavated areas shall be divided into manageable sections, which have to be defined upon sketches. The excavated areas shall be monitored by the Geotechnical Engineer to ensure that any unsuitable material does not appear. Where unsuitable material appears, it shall be removed.
The excavated formation surface shall be treated by scarification, moistened and compacted, according to the specification criteria. All areas shall be tested and the results recorded.
Where areas are to receive fill, the material that has been excavated shall be transported to the fill area, tipped, leveled, moisture conditioned and compacted. The material shall be spread and leveled in 200mm layers. The areas to be filled shall be divided into manageable sections that shall be defined upon a sketch. The fill layer shall be moistened and compacted to achieve the required specification criteria. No further fill activity shall be conducted upon an area that has not been approved and released by the Geotechnical Engineer. Attention shall be observed at edges and slopes, to ensure that compaction criteria are achieved. Additional layers of fill material, shall be placed in the same method as described above, until the desired elevation has been achieved.
Production procedure.
Verification exercise for fill activity on record has been conducted to establish the economical and effective method for the fill activity.
Import and place fill to controlled areas of approximately 25m wide by 100 - 150m long.
Spread and level the imported fill.
Add water to the fill layer by passing the water tanker over the fill layer. The water tanker should pass over the layer twice. A time gap of approximately two hours is allowed for the water to soak into the fill material.
The layer is now mixed with the grader until a uniform blend of moist material is achieved.
Additional water is added by passing the water tanker over the layer in a uniform sequence. A time period of approximately one-hour is allowed for this water to soak into the fill layer.
The fill layer is mixed again with the grader, leaving the fill level to the correct grade.
Vibrating rollers shall now compact the fill layer in a logical sequence that densifies the layer uniformly.
Field Density Testing of the layer shall be conducted to the ITP requirement.
Gravel Finishing- Installation of gravel crushed or natural shall be carried out by spreading to the specified thickness of 100 mm or 50 mm as the case may be over the prepared surface uniformly to site feasibility. Mechanical or manual adjustment shall be carried out to the spread gravel followed by mechanical compaction to bring the material to undisturbed acceptable profile. Work shall be done to the area indicated on IFC drawings.
Vegetal Soil Surface - Landscaping- Humus for the grass shall be spread over the IFC drawing indicated area on flat as well as sloped surface to specified thickness & leveled roughly by mechanical means. Irrigation network piping & fittings shall be carried out to the indicated areas on IFC drawings. Supply, laying & pipe connection shall be carried out accordingly to the sub contract scope.
Protection of Existing Services
From the provision of existing site drawings, provided by the relevant authorities within ASAB, existing services shall be located, and exposed by hand excavation.
The Survey Team shall check and accurately record these existing services. A line of pegs shall be positioned to indicate the route of the existing services. The use of warning tape, and/or nylon cord, to indicate and protect the route of the service shall be conducted. The Survey Team shall inform the Infrastructure Engineer of the exact location of the service relative to the warning flags.
Should an existing service be disbanded or redundant, that service shall be exposed, to allow confirmation of the status of the service. The Infrastructure Engineer, through the Technip representative, shall ask the relevant authority within ASAB, to review the excavated service and confirm the status and action he requires for the removal of the service. The redundant service shall be removed under the supervision of the Infrastructure Engineer according to the agreed criteria of that relevant authority.
Where an existing live service remains during the site preparation activity, such as the 33KVA electric cable, that existing live service shall be protected.
The Survey Team shall locate the live service upon the ground using spray paint or small pegs. At periodic locations along the route of the existing live service, defined by the Survey Team, small hand dug pits shall be excavated, to identify the service. The purpose of this exercise is to ensure that the location of the live service is accurate.
Ten meters (10m) either side of the route of the existing live service shall be erected posts. A nylon cord, with warning tape streamers, shall be strung between the posts. This shall clearly indicate the service and its route. The posts shall fixed be at suitable & sustainable centres.
Signboards indicating what the live service within the marked corridor exactly is, shall be displayed at sufficient locations along the route.
Where temporary roads cross-existing cables, sufficient suitable fill material shall be placed on top of the cables to afford adequate protection to by distributing the vehicle axle loadings safely minimising stress concentration.
The Safety Officer shall periodically check the condition of the barriers, where necessary refurbishment shall be conducted
Galvanized fence-Galvanized mesh shall be installed according to the IFC indicated location. Supply shall be affected according to the requirement. Excavation shall be carried out for the post embedment constructed to the manufacturer instructions by using RCC plug in to the holes to support the post of the fence.
Reinforced concrete fence- Pre-cast RCC fence panels shall be erected & connected to the already carried out foundations & inserts to the fence requirement. Individual elements shall be stocked properly.
Prefabricated reinforced concrete fence- Pre fabricated elements of the fence shall be procured from the market to the IFC indication & erected on site & connected to the already carried out foundations & connected to the structural requirement.
Vehicle gate- gates in complete package shall be supplied to the IFC & specification requirement as approved & installation be carried out accordingly to the manufacturer instructions & details.
Pedestrian gate- pedestrian gates in complete package shall be supplied to the IFC & specification requirement as approved & installation be carried out accordingly.
Road barrier- road barriers in complete package shall be supplied to the IFC & specification requirement as approved & installation be carried out accordingly.
Fence Erection.
The final grade level of the area shall be the commencement point for the fence construction.
A level survey shall demonstrate the accuracy of the site grading activity.
The Survey Team shall set out the line and level of the fence, including post locations for all elements.
Using a machine-mounted auger, 300 and 450mm diameter holes as appropriate, shall be drilled for the fence post foundations.
The drilled holes shall be cleaned and bedded to the correct base level.
The fence post foundation shall be placed in the drilled hole to the correct line and level.
Dune sand shall be compacted around the foundation.
The fence fabric shall be strung and tensioned as per the drawing details and manufacturers recommendations
Using hand tools, a trench shall be excavated for the ground beam.
The ground beam shall be placed to the correct line and level.
Suitable fill material shall be used to compact around the ground beam.
The fence fabric tie staple shall be grouted in position once the fence fabric is tensioned.
The gap between the ground beams at the location of the fence post shall be concreted to form a continuous beam.
QC procedures shall be closed out on an on-going basis.
Excavation
The engineer shall ensure that the current drawings relating to the excavation activity are approved for construction. The engineer shall ensure that there are no conflicts with existing services or other discipline issues. Constructability from the drawing shall be ensured.
The surveyor shall provide line and level engineering that shall enable the excavation of the structure.
A system for quick reference shall be established.
The surveyor shall inform the excavation foreman of these lines and levels.
The excavation foreman shall direct the excavation equipment in an agreed sequence. Excavated material shall be classified by laboratory test. Unsuitable material shall be removed off site to the tip area. Where material is classified as suitable, the required volume shall be stockpiled on site in an agreed location.
Safety barriers shall be erected as the work proceeds.
Where applicable, the sides of the excavation shall be sloped.
There is no requirement for ground de-watering equipment.
Should restrictions be imposed by adjacent structures etc that would make sloping of the sides un practical, shoring or support of the excavation sidewalls shall be agreed with Technip on site.
The surveyor and site engineer shall check the excavation to confirm compliance with his levels and lines. A survey shall be conducted of formation level upon completion of the excavation.
The formation shall be visually inspected for unsuitable material. Any such material shall be removed.
The formation shall be scarified and compacted to the required specification criteria. The laboratory test results shall be provided. Upon acceptance of these results, the area shall be released for consequent activities.
Backfill to structures
The engineer shall ensure that all subsequent activities are passed and completed. Cleaning shall be done.
Upon approval to backfill, the engineer shall instruct the foreman to carry out this activity.
The backfill material shall be sourced from the suitable material stockpile. The backfill material shall be placed in layers according to the specification. The layer shall be moisturized and compacted to the agreed criteria.
Each backfill layer shall be field density tested by the laboratory. An acceptable test result shall allow the next layer of backfill to be placed and compacted. This process shall continue until the whole fill is completed.
Upon completion of the backfill activity, the area shall be cleaned of waste materials and left tidy for the next activity to follow.
Any safety barriers shall be removed to the safety store.
Ignore if not applicable
Piling Typical - Equipment mobilization, Piling rig moving- shall be done accordingly & pile location set out by the surveyor. In case of pre cast piles, the rig shall drill the pile bore to specified dia vertically using steel insert protection at pipe toe. Pre cast/stressed piles shall be inserted into the bore with compression impact hammer gradually till the whole pile is driven into the strata.
It shall be ensured that the pile remains vertical & in its set out location.
After the pile is driven, sonic test, dynamic auscultation & load test shall be conducted to specified requirement. Load test shall be conducted by reaction truck loading or the actual load applied in cycles. Dynamic auscultation test shall be conducted to the code requirement. All records shall be maintained. After piles have been driven, demobilization of equipment shall be effected
Pile head preparation shall be carried out by cutting pile heads to expose the rebar for connection to pile head or cap rebars. After proper placement of the rebars of the pile cap & the pile head, formwork shall be erected & concrete poured for the pile head or cap. Curing shall follow to agreed procedures.
Cast in place concrete piles-
Driven cast in place concrete piles with permanent casing- Location of the piles shall be set out.
Casing shall be driven truly vertical into the location using the rig & continued until the design depth is reached. Soil column shall be taken out by pressurised water. Casing base shall be cleared & inspection for the plumb & profile conducted. Reinforcement cage provided with concrete spacers shall be placed into the casing properly fixed. After inspections, concrete shall be poured into the casing keeping a maximum drop of concrete not more than 2 m. Concrete vibrator shall be kept working into the poured concrete & gradually withdrawn progressively as the concrete moves up. In case casing is to be withdrawn, it shall also be gradually withdrawn following the gradual & progressive pour. While withdrawing, care has to be exercised that verticality is not disturbed. Pouring shall be completed up to the head of the pile. All accumulated water shall be removed by pumping continuously & piling area kept dry. Pile shall be poured continuously avoiding any construction joint. All excavated earth shall be removed from site.
Pile load test shall be conducted after lapse of specified duration. Engineer shall select the piles to be load tested. Cyclic load testing shall be applied for 72 hours loading & unloading & reloading. Test record shall be maintained according to ITP & procedural requirement. To ascertain the pile integrity, sonic test shall be conducted by a hammer impact & the transmission of the sonic waves recorded using the standard equipment. This test shall be conducted for all piles for it ascertains the integrity & transparency of the material used.
After the piles have been tested successfully, preparation of the pile head shall commence. Extra portion of the concrete shall be cut to the pile cap base level. All reinforcement effected by concrete shall be cleaned, new reinforcement for the pile cap & column starter bars installed. Preparatory form shall be erected for the pile cap. Concrete spacer shall be fixed properly. Any tie up beams preparatory works shall be carried out. After the inspections are conducted, concrete pouring shall be carried out & the unformed surface finished smooth enough to receive concrete protection.
Ensure the side are truly aligned as well as in plumb. Ensure dimensions are correct within tolerable limits. Ensure reinforcement placed to the design details. Ensure the spacers are properly fixed & all steel bar in its design locations. Ensure concrete level at top is fixed properly using 25 x 25 mm plastic chamfers. Ensure the vertical corners edges have been fixed with plastic chamfer.
Since, most of the pile caps shall be thick sections, special arrangement shall be made for curing using saturated Hessian, polythene sheets and clean sand fill below the coverings so that no heat transmission is permitted from the concrete surface. This type of curing is called thermal curing. During high temperatures, water shall be sprinkled on the forms from the sides to ensue minimum heat loss in early days of concreting.
Bored Continuous flight auger (CFA) Piles, reinforcement for Continuous Flight auger (CFA) piles-
Similarly, CFA piles shall be continuously augur bored into any soil, reinforcement place in & concrete poured. All tests shall be conducted according to previous explanations.
After the piles have been cast, location survey shall be conducted for 5% of the poured piles.
Micro Piles, Drilled micro piles, reinforcement for Micro piles,
Jet Grouting soil Improvement system- For the proposed piles, locations shall be set out. Rotary mast shall be utilized to drill a bore into the strata without removing the soil & high pressure cement grouting applied into the bore. Curing shall be carried out to the requirement. All debris shall be removed from site.
Pile test- Sonic test by hammering for construction uniformity & homogeneity, Dynamic auscultation test by impedance, Load testing (compression), Load testing tensile test, Load testing horizontal loading test, pile location survey,
Earthwork-
Grubbing - According to the scope included on the IFC drawings, trees, plants, bushes, roots shall all be removed completely from the soil ensuring that the soil is not effected adversely. These uprooted green materials shall be collected at one place for suitable disposal to a designated area.
Scrubbing- According to the scope included on the IFC drawings, vegetation topsoil shall be removed irrespective of its consistency & water content.
General Excavation-
In the controlled plant area, prior to commence with the excavation, legal ‘permit to work’ shall be obtained from the ‘operating authority’
It shall be made sure that no existing services run under the proposed area from the concerned authorities record. Necessary benchmarks shall be established for surveying controls & monitoring purpose. Where it is feasible to excavate the whole unit area involving all foundations & beams etc. using heavy excavation equipment, general excavation should be carried out which allows saving in excavation time keeping the area tidy. Such area shall be set out to the IFC details, grids marked on the timber rails around the area periphery. Additional marking shall be set for the general area limits & proposed convenient ramp to allow easy access & egress to & from the area. Proper safety warning signs shall be erected around proposed general area. Signs shall include KEEP AWAY DEEP EXCAVATION, HARD HATS ZONE etc
In case of any mishap caused to the existing services, immediate information shall be notified to the concerned authority so that corrective action can be undertaken.
Excavation shall be started by excavator directly loading the material into a dumper truck which shall remove the excavated material from the location to stock pile areas in case the material is suitable for re use as backfill or to a designated dumping area otherwise. A surveyor shall constantly monitor excavation formation level. Environment protection arrangements shall be charted out to keep the site tidy. During excavation in case of loose soils such as sand whose angle of repose does not permit, shoring shall be arranged around the periphery to prevent soil subsidence. Excavation & soil removal shall continue to reach the formation level. No further excavation shall be carried out. All debris shall be removed from area, dressing conducted on the rough formation to bring it to required profile. The surface shall be watered & compaction carried out using heavy road roller of at least 8 T capacity, which work in strips in parallel overlapping the previous strip. Compaction shall be conducted until rebound occurs. Field density test shall be conducted to ensure the correct formation density has been achieved, atterberg’s limit & moisture content are within acceptable limits.
In case, soil improvement is to be applied, further excavation shall be carried out to the design thickness of the improved strata. After preparing the formation for the engineered fill, selected granular material shall be placed into the prepared formation in layers, watered & compacted. Field density test shall be conducted for each layer of fill. Plate bearing test may also be carried out to know the ultimate & safe bearing capacity of the improved strata. Now the formation is ready to receive the foundations on it. Formation levels shall be recorded.
In case water level is high & dewatering is necessary, proper plan shall be made to install the dewatering system until the whole of area is constructed up to the ground level. Water shall be pumped out & disposed to a suitable agreed discharge point keeping the location tidy. But in this case, according to investigation report, soil is free of water. No dewatering is required.
Sectional Excavation-
In the controlled plant area, prior to commence with the excavation, legal ‘permit to work’ shall be obtained from the ‘operating authority’
Where particular foundation or trench for a cable or an isolated or combined footing or vessel base etc is to be excavated, excavation shall be carried out only for that particular area. Necessary benchmarks shall be established. Setting out shall be done accordingly for the extent of the area & grid control established. Safety signs shall be established. All arrangement for the necessary shoring resorted in advance. Excavation shall start by mechanical equipment removing the excavated soil into a dumper truck for disposal to stockpile or to a designated area. In case manual excavation is to be carried out for the protection of the existing services, no machine shall be used until specially permitted after the exposure of all existing services. In case of fibre optic cable exposure, only water jetting should be used to excavate the area. In case of any mishap caused to the existing services, immediate information shall be notified to the concerned authority so that corrective action can be taken.
In case water level is high & dewatering is necessary, proper plan shall be made to install the dewatering system until the whole of area is constructed up to the ground level. Water shall be pumped out & disposed to a suitable agreed discharge point keeping the location tidy. But in this case, according to investigation report, soil is free of water. No dewatering is required.
Embankment- Typical
Profile shall be set for the proposed embankment base. Centreline of the embankment shall be marked. Loose soil from the base shall be removed. Embankment template shall be fixed at various spacing longitudinally. Backfill shall be carried out in layers 250 mm loose thick, watered & compacted using heavy roller. Whole layer shall be compacted to achieve non-structural fill density. Field tests shall be conducted according to the specification requirement. The quantity of samples to be taken for test shall depend on the extent of area under compaction. Filling shall continue in layers until the whole section is completely backfilled. Every layer shall be tested accordingly. Structural backfill compaction density test shall be ensured for the embankment to receive heavy loading such as tanks, roads, foundations etc.
Earthwork for Storage facility-
Excavated material from the other excavation areas shall be stockpiled at designated areas. Reusable material for filling shall be screened out regularly from the stockpiles. Compliance of this material shall be ascertained by conducting classification tests & if necessary, additional deficient materials of required grading be added to bring the stock to acceptable plasticity index or non-plastic standard.
This material shall be used for the formation of the storage facility foundation fill works.
Tank foundation area shall be set out to IFC details. Design profile shall be established & fill layers commenced with. Every layer shall be filled 250 mm thick watered & compacted down to 200 mm. Field density test shall be conducted after the compaction to allow the commencement of the upper layer. All forthcoming layers shall be filled adhering to same procedure & tested.
The top layer to receive the bituminous surface finish shall be prepared suitable accordingly. Surface shall be cleaned, levelled properly & top of surface finish level established. Surface shall be primed with approved material. Conglomerate of 10 to 20 mm size, closed with 5 mm aggregates & bituminous emulsion @ 1 kg/m^2 or in accordance with Contractor standard to from a total compacted thickness 100 mm.
Surface shall be inspected & density test conducted by taking out the compacted cores.
Similar operations shall be carried out on the sloping areas.
Earth dikes- To retain the basins
Similarly, the filling works for the earth dike shall be carried out as stated in the foregoing from excavated material & also if required from the supplied material as the case may be.
Body of the dyke shall be covered by application of an approved material to give acceptable finish to the body of the dyke per provisions on the IFC drawings.
Soil Improvement- By Soil Substitution
Wherever shown on the IFC drawings, the scope of replacement of the existing soil from the plant area, existing soil shall be excavated out in specified thickness & removed to dumping areas.
Suitable backfill material shall be procured from an approved source including the site stockpiles & backfilling carried out to replace the excavated portion of the plant area.
Watering & compaction shall be carried out all according to approved procedures. Testing shall be conducted to ascertain the field density achievement.
Soil Treatment-
Wherever shown on IFC drawings, the scope to treat the soil belonging to an area, the soil shall be stripped out from the area & transported to stockpiles for the purpose to add into this material cement or lime, water & mix mechanically. After the mixing of the soil, re-transport to the original location shall be carried out, spread on to the area, levelled & compacted in acceptable thickness & bring the profile to the defined levels. Whole area in the scope shall be applied treatment accordingly.
Walkways kerb-
Wherever shown on IFC drawings, the scope of laying & fixing the walkway kerbs, proper preparation of the formation duly compacted shall be carried out. Blinding shall be laid to the required profile in gradient. Kerb shall be placed on the blinding using defined cement mortar mix sealing the base of kerb & end to end joints perfectly. Alignment of the kerb, gradient, verticality & joint thickness shall all be controlled. Any deviation in the alignment shall be within acceptable limits.
Walkways Foundation-
Granular material shall be filled below the walkway finishes given required gradient. This fill shall be compacted to the non-structural requirement.
Walkways Finishes-
Finishing over the walkway foundation shall be applied according to IFC drawings & specification requirement
Wherever shown on IFC drawings, 30 mm thick rolled thickness of bituminous conglomerate shall be applied.
Wherever shown on IFC drawings, 100 mm thick RC concrete with prefab mesh paving given float finish shall be applied with required number of joints properly spaced.
All loose soil shall be cleared and formation level made up and well compacted & pesticide treatment applied if so specified.
Laying Kerb stones Typical Sample
Setting out kerb excavation lines according to drawing
Excavation up to the formation level i.e. 450mm from the kerb top level
Form work fixing and pouring grade 20 concrete 450mm wide and 150 mm thick
Formwork fixing and pouring grade 20 concrete 150mm wide and 150 mm thick high
Pouring grade 20 concrete all according to approved procedures
Fixing 12 T re-bars @ 200 c/c vertically supported to forms
Bedding in cement mortar 1:3, 25mm thick for kerb stones grade 20
Fixing kerb on the mortar to the true lines and levels with chamfer facing pavement & jointing with mortar. Alignment tolerance shall be 3 mm in 75 mm both ways vertically as well horizontally. End to end butting mortar thickness shall be 3 mm
Placing haunch back fillet concrete grade 20, as shown in (triangular fillet section)
Filling up to top of vertical concrete with earth fill & compaction
All areas below proposed interlocking course to be filled with 100 mm thick sand screed all according to conventional procedures
QC inspection shall be conducted for kerb laying approval and ITP requested to be signed off by QC
(Laying Paving Interlocking blocks)
Thickness of the interlocking blocks 60mm
Thickness of the sand screed bedding 100mm
Plank runs shall be used to allow barrows to move on to avoid level disturbance
First surveyor shall set out the pattern borders all according to shop drawing as well as design drawings
First Grey or other approved colour interlock blocks shall be laid to position & profiled to form the border pattern.
The blocks shall be laid in full but at the edges of the obstacles such as inspection covers where cut blocks may be required, whole blocks shall be laid first wherever possible and the trim able blocks exactly marked & cut to the required size.
After profile is well formed to the approval, the fill in course to the border areas shall be carried out by laying Red or as approved colour blocks
After sufficient blocks have been laid, sand bedding shall be carried out using a plate vibrator pressing the blocks to the required level in 2 passes covering entire area with each pass to make the bedding even
Sand screed shall be spread on the surface of the blocks with 2 more vibrator passes applied & brushed under the leading edge of the vibrator to allow the joints vibrated
QC inspection shall be conducted & QP requested to approve the paving
Ignore if not applicable
Roads, Yards, Paving (Asphalt)
Road Works Typical Sample
The following sequences shall be involved to do the roadwork
Clearing all services according to the project drawings and inspections/Approvals
Preparation of the area to be structured by removing topsoil, placing in imported fill material, profiling levels to the project drawing & compaction.
Applying pesticide treatment if required
Application of all pre work items such as construction of kerbstone to complete sectional details shown on project drawing miscellaneous details.
Inspection of the surface
Sub base class B material shall be spread on the area in strips of required thickness keeping more than design thickness by 25mm i.e. 150+25 mm
Sub base approved fill material to interlock the class B material shall be spread on the spread material & dry rolling carried out to produce correct profile of the section
Water shall be sprayed on the surface to make it penetrate in to & around all the voids of the spread material & compaction by heavy roller carried out to densify the whole course.
After required number of passes probably 6 given by 18 to 12 tonne rollers bringing the laid material to the required thickness 150 mm & exhibiting rebound on the surface, the compaction by rolling shall cease.
Density test shall be conducted all according to approved ITPs requirement
Compacted course shall be left for drying in due course allowing it to be ready to receive Prime Coat MC1. Drying time shall not be less than 48 hours.
Prior to the start of the Prime course spreading, any defect is observed during visible inspection shall be repaired in rectangular or square shape or as agreed with.
Asphalt concrete
Asphalt concrete shall be laid in widths of driveway roads according to the project drawings.
Wearing course thickness being 40mm & that of dense bitumen binder course 80mm
Paving works shall be carried out in 2 stages
Stage 1
Laying & compacting bottom bituminous binder course
Stage 2
Laying & compacting top wearing carriageway
Surface preparation
Prior to the application of the dense bitumen binder course, already laid & compacted aggregate base course shall be prepared suitable for this purpose
Base course shall be corrected of any deviation more than 13mm from the designed profile at any point & not more than 9mm in 3m on the longitudinal grade at any location by either adding to or removing from the surface the deficient or redundant material respectively to bring the surface to the design shape, watered & compacted in accordance to the specification all as stated above
Main Operations
The following main operations are involved
Re-preparation of aggregate base course surface with water & compaction by pneumatic roller
Application of Priming coat & drying out
Application of 60mm thick dense binder course
Power brooming the completed dense binder course
Application of Tack coat & drying out
Application of 40mm thick bitumen concrete wearing course
Mixing
All materials shall be mixed at an approved calibrated & approved Asphalt plant
All trucks and other equipment as included shall be readily available for inspection
Transportation
Material shall be transported from the plant to the planned location in good condition by trucks cleaned of all foreign material & covered with tarpaulin to prevent dust invasion in inclement/adverse weather conditions
It shall be ensured by obtaining observations using thermometer that the material when laid is within 130 to 165degree Celsius
Application
Coverage
Primer coat 0.8 to 1.4 litre/ m^2
Tack coat 0.4 to 0.7 litre / m^2
Share with your friends: |