Geotechnical Engineering Circular No. 9 Design, Analysis, and Testing of Laterally Loaded Deep Foundations that Support Transportation Facilities
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Soldier Rev B
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- 11.4 INTERMEDIATE GEOMATERIALS (IGM)
- 11.5 SEISMIC DESIGN CONSIDERATIONS
- 12. PRELIMINARY ASSESSMENT OF METHOD FOR GEC 9
| 11.3 ROCK SOCKET DESIGN Much of the design guidance and available information for lateral load analysis of deep foundations focuses on soil. Specific p-y curves for rock is a significant gap in the available industry information, especially considering the potential variability in strength, fracturing, elasticity, and other properties of various rock types and masses. 287 In addition, design approaches to deal with high shear loads at the rock surface in short piles is an issue that lacks guidance in the available publications researched for this report. 11.4 INTERMEDIATE GEOMATERIALS (IGM) There is a growing awareness within the geotechnical design community that intermediate geomaterials (IGMs), such as decomposed or highly weathered rock, partially cemented sands, and some marl formations, are not adequately addressed in available publications and resources. This is a gap in the state of the practice for lateral design of deep foundations as well. Most available guidance or information, such as p-y curves, is for either sand or clay soils. Therefore, current practice requires making simplifying assumptions or characterizations when dealing with design in IGMs. 11.5 SEISMIC DESIGN CONSIDERATIONS Several of the available publications discuss seismic design approach and criteria. However, a noticeable gap in the available information is p-y curves for liquefied soils. 11.6 BATTER PILES In general, the literature reviewed either did not address batter piles specifically or only made passing mention of them. The literature that includes discussion on analyses and approaches for analyzing piles for lateral load applications only addressed vertical piles. Where batter piles are mentioned, it is indicated that batter piles can be used to resist lateral loads through axial and end bearing capacity. 12. PRELIMINARY ASSESSMENT OF METHOD FOR GEC 9 Based on this literature review, it is evident that there is not a consistent or unified approach among various agencies and practitioners for the current state of the practice for lateral load design of deep foundations. The main standard between agencies and countries is the concept that either the Broms method or a SSI method (typically p-y method) should be used to analyze deep foundations which are controlled by lateral design. Other topics related to the selected design depth, head fixity, deflection limits, Limit States, and engineering responsibilities are not consistent, but generalities do tend to exist. Below is a summary of the anticipated direction for the design procedure that will be presented within GEC 9. Download 6.03 Mb. Share with your friends:
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