Rational Guidance to Determine the Maximum Factored Axial Compression Load a Driven Pile Can Support
Federal Highway Administration (FHWA) developed publications that address several issues and problems that highway agencies face in implementing load and resistance factor design (LRFD) design for driven piles based on AASHTO LRFD Bridge Design Specifications. Initially in this paper, new improvements for consideration of downdrag effects in the design of driven piles are presented followed by discussion of how these improvements impact the design procedure for driven piles presented in previous FHWA publications. The maximum factored axial compression load a driven pile can support at the strength limit state (Qfmax) is needed to start the design and estimate the preliminary number of piles in a pile group and finalize the design. Procedure to estimate Qfmax is not discussed in AASHTO LRFD. The current common practices used by highway agencies to determine Qfmax are conservative and require lengthy design time. To address these problems, a new rational guidance to determine Qfmax at the beginning of the design is presented. Qfmax is determined by addressing all the strength limit states for compression resistance of a single pile, geotechnical, drivability, and structural. A new and improved procedure is developed to address pile drivability in the design by determining the maximum depth (length) the pile can be safely driven to without damage, Lmax. The results obtained from addressing all the strength limit states for compression resistance of a driven pile are summarized in a design chart that can be used to optimize and finalize the design. Finally, a comprehensive LRFD Design Example is solved to demonstrate the driven pile design guidance presented in this paper. The benefits of setup and using static load tests are also demonstrated in solving this example.
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Supplemental Notes:
- This paper was sponsored by TRB committee AFS30 Standing Committee on Foundations of Bridges and Other Structures.
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Corporate Authors:
500 Fifth Street, NW
Washington, DC United States 20001 -
Authors:
- Abu-Hejleh, Naser M
- Kramer, William
- Mohamed, Khalid
- Long, James H
- Zaheer, Mir A
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Conference:
- Transportation Research Board 96th Annual Meeting
- Location: Washington DC, United States
- Date: 2017-1-8 to 2017-1-12
- Date: 2017
Language
- English
Media Info
- Media Type: Digital/other
- Features: Figures; References; Tables;
- Pagination: 22p
- Monograph Title: TRB 96th Annual Meeting Compendium of Papers
Subject/Index Terms
- TRT Terms: Bridge design; Compression; Limit state design; Load and resistance factor design; Load tests; Pile driving; Support piles
- Identifier Terms: AASHTO LRFD Bridge Design Specifications
- Subject Areas: Bridges and other structures; Design; Highways;
Filing Info
- Accession Number: 01626825
- Record Type: Publication
- Report/Paper Numbers: 17-05334
- Files: PRP, TRIS, TRB, ATRI
- Created Date: Feb 27 2017 9:26AM