Published by department of transportation

46-1.02 MATERIALS

46-1.02A General

46-1.02B Sheathing

HDPE sheathing must have a density of from 940 to 960 kg/m³ when measured under ASTM D792.

Smooth and corrugated sheathing, including joints, must be:

1. Strong enough to prevent damage during construction

2. Watertight

3. Chemically stable without embrittlement or softening

4. Nonreactive with:

4.1. Concrete

4.2. Steel

4.3. Corrosion-inhibiting grease, if used

46-1.02C Grout

Cement must comply with section 90-1.02B(2).

Water must comply with section 90-1.02D. Do not exceed 5 gallons of water per 94 lb of cement.

Admixtures must comply with section 90, except they must not contain chloride ions in excess of 0.25 percent by weight.

46-1.03 CONSTRUCTION

46-1.03A General

1. Fall on traffic

2. Flow across shoulders or lanes occupied by traffic

3. Flow into landscaping, gutters, or other drainage facilities

46-1.03B Drilling

Drilling equipment must produce straight, clean holes.

Use the rotary or rotary percussion drilling method to drill ground anchor or soil nail holes in the foundation material.

At locations where caving is anticipated, keep enough casing and auger lengths on the job site to maintain uninterrupted anchor or nail installation.

At locations where hard drilling conditions, such as rock, cobbles, boulders, or obstructions, are anticipated, keep a down-hole pneumatic hammer drill rig and drill bit available on the job site for drilling holes.

Clean the holes to remove material from drilling activities. Do not use water to clean soil nail holes unless authorized.

Dispose of drill cuttings under section 19-2.03B.

46-1.03C Installation

There must be no evidence of distress in the plastic sheathing or crushing of the grout within the pregrouted sheathing.

Do not insert an anchor or nail into a hole until the hole has been inspected by the Engineer.

Install the anchor or nail in the drilled hole promptly so that caving or deterioration of the hole does not occur.

If you cannot insert an anchor or nail into a drilled hole to the required depth without difficulty, remove the anchor or nail and clean or redrill the hole. Do not force or drive a partially inserted anchor or nail into a drilled hole. Partially inserted anchors or nails are rejected.

For open-hole drilling methods, keep hole-cleaning tools on the job site. The tools must be suitable for cleaning drilled holes along their full length just before inserting the anchor or nail.

46-1.03D Grouting

1. Add water to the mixer followed by cement and any admixtures or fine aggregate.

2. Mix the grout with mechanical mixing equipment that produces a uniform and thoroughly mixed grout.

3. Agitate the grout continuously until the grout is pumped.

4. Do not add water after the initial mixing.
Grouting equipment must be:

1. Capable of grouting at a pressure of at least 100 psi

2. Equipped with a pressure gauge having a full-scale reading of not more than 300 psi

46-1.03E Research Investigation

46-1.04 PAYMENT

46-2.01 GENERAL

46-2.01A Summary

A ground anchor consists of a steel bar or strand tendon with an anchorage assembly that is placed in a cored, formed, or drilled hole, and then grouted and stressed.

46-2.01B Definitions

46-2.01C Submittals

At least 40 days before using the corrosion-inhibiting grease, submit a test sample from the lot to be used and test data showing compliance with the specifications for strand coating and encapsulation.

46-2.01D Quality Assurance

46-2.01D(1) General

Not Used

46-2.01D(2) Quality Control

46-2.01D(2)(a) General

Strand tendons, bar tendons, bar couplers, and anchorage assemblies must comply with section 50-1.01D.

46-2.01D(2)(b) Load Testing

46-2.01D(2)(b)(i) General

Performance test ground anchors as described. Proof test all ground anchors that are not performance tested.

Perform load testing against the completed structural element shown. Do not test directly against the soil.

Do not stress against the concrete until it has attained a compressive strength of at least 2,880 psi or has cured for at least 7 days.

Bearing pads must be a minimum of 1 foot away from the edges of the drilled hole.

If a ground anchor fails to comply with the acceptance criteria, redesign or replace the ground anchor. Do not retest a ground anchor unless you post-grout the anchor bonded length after the unacceptable test.

46-2.01D(2)(b)(ii) Test Procedure

Conduct the performance and proof tests as follows:

1. Incrementally load and unload the anchor as shown in the following table:

Loading Schedules
Performance test		Proof test
Load increment	Hold time (minutes)	Load increment	Hold time (minutes)
AL	Until stable	AL	Until stable
0.20FTL	1–2	0.20FTL	1–2
AL	Until stable	0.40FTL	1–2
0.20FTL	1–2	0.60FTL	1–2
0.40FTL	1–2	0.80FTL	1–2
AL	Until stable	1.00FTLa	10 or 60
0.20FTL	1–2	AL	Until stable
0.40FTL	1–2	--	--
0.60FTL	1–2	--	--
AL	Until stable	--	--
0.20FTL	1–2	--	--
0.40FTL	1–2	--	--
0.60FTL	1–2	--	--
0.80FTL	1–2	--	--
AL	Until stable	--	--
0.20FTL	1–2	--	--
0.40FTL	1–2	--	--
0.60FTL	1–2
0.80FTL	1–2	--	--
1.00FTLa	10 or 60	--	--
AL	Until stable	--	--
NOTE: FTL = factored test load shown AL = alignment load = 0.10FTL aMaximum test load

2. Apply each load increment in less than 1 minute and hold it for the length of time shown in the table titled "Loading Schedules."

3. Measure and record the applied test load and the anchor end movement at each load increment.

4. When applying the maximum test load:

4.1. Hold the load constant for 10 minutes.

4.2. Start the observation period for the load hold when the pump starts to apply the last load increment.

4.3. Measure and record the anchor end movement at 1, 2, 3, 4, 5, 6, and 10 minutes.

5. If the movement measured from 1 to 10 minutes is greater than 0.04 inch:

5.1. Hold the load constant for an additional 50 minutes.

5.2. Measure and record the anchor end movement at 15, 20, 25, 30, 45, and 60 minutes.

5.3. Plot a creep curve as a function of the logarithm of time, showing the anchor end movement from 6 to 60 minutes.

6. Reduce the load to the ending alignment load and record the residual movement.

46-2.01D(3) Department Acceptance

46-2.01D(3)(a) General

The Department tests the efflux time of the grout under California Test 541.

46-2.01D(3)(b) Load Testing

46-2.01D(3)(b)(i) General

Not Used

46-2.01D(3)(b)(ii) Acceptance Criteria

Ground anchors that are performance- or proof-tested must comply with the following:

1. Total measured movement at the maximum test load minus the measured residual movement at the ending alignment load exceeds 80 percent of the theoretical elastic elongation of the sum of the unbonded length and the jacking length.

2. Creep movement complies with one of the following:

2.1. For a 10-minute load hold, the creep movement measured from 1 to 10 minutes is less than 0.04 inch.

2.2. For a 60-minute load hold, the creep movement measured from 6 to 60 minutes is less than 0.08 inch and the creep rate is linear or decreasing in time logarithmic scale from the 6- to the 60-minute reading.

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