Thesis
Analytical performance evaluation of hollow prestressed piles and pile-cap connections in the I-5 Ravenna Bridge
Washington State University
Master of Science (MS), Washington State University
2008
Handle:
https://hdl.handle.net/2376/103275
Abstract
The Washington State Department of Transportation (WSDOT) developed a bridge seismic retrofit program in 1990 in order to address seismic risk associated with state owned bridges. There are 22 bridges with hollow-core pile foundations located on I-5, I405, and State Route 520 in the Puget Sound region of Washington State. Sudden, catastrophic failure has been observed in tested piles of this configuration at displacement ductilities of four or less. In order to investigate the behavior of the in situ hollow-core piles and pile-to-crossbeam connections used in the I-5 Ravenna Bridge near Seattle, Washington, a series of nonlinear 3D finite element (FE) analyses were performed using ABAQUS/Standard. In addition, 2D nonlinear Winkler beam models were developed using SAP2000 Advanced Nonlinear in conjunction with XTRACT in order to evaluate its model's ability to predict failure. The FE and beam models developed were calibrated against existing experimental data. The proposed FE model is capable of capturing the behavior of prestressed hollow core concrete piles. During calibration, load capacity and displacement ductilities at yield and failure were well-predicted with an over-prediction in strength of roughly 20%. Results from the FE analyses for the in situ hollow pile illustrated that confining pressure supplied by the soil does not provide appreciable strength to the cover concrete. The subgrade plastic hinge was found to vary from 2.88 to 3.0 pile diameters and was located, on average, 610 mm (24 in.) below ground level, depending on the soil model. The Winkler beam models were found to provide a conservative approximation for the load-displacement response of the 3D FE models. The simplified analyses underpredicted load capacity and displacement ductility capacity by roughly 30 percent. For the connection, a 50 percent reduction in axial load reduced the post-yield moment response by roughly 10 percent. Modeling the connection as fixed reduces the rotation capacity by nearly 60 percent while the moment capacity is virtually unaffected. It is recommended that the rotational stiffness of the connections be taken as the equivalent energy elastic-plastic response of the moment-rotation response obtained from the proposed finite element model.
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Details
- Title
- Analytical performance evaluation of hollow prestressed piles and pile-cap connections in the I-5 Ravenna Bridge
- Creators
- Steven M. Greenwood
- Contributors
- William F. Cofer (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Civil and Environmental Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900524859101842
- Language
- English
- Resource Type
- Thesis