Evaluation of Seismic Deformation Analysis Approaches for Bridge Embankments

Details

• Creators:
  Armstrong, Richard
• Corporate Creators:
  Natural Hazards Risk and Resiliency Research Center (NHR3). Department of Civil and Environmental Engineering. University of California, Los Angeles
• Corporate Contributors:
  California. Department of Transportation
• Subject/TRT Terms:
  Bridge Embankment Modeling Bridge Engineering Deformation Earthquake Engineering Earthquake Scenario Evaluation Embankments Equivalent-Static Analysis (ESA) Evaluation Liquefaction Liquefaction-Induced Deformation Nonlinear Deformation Analysis (NDA) Nonlinear Systems Static Structural Analysis

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• Publication/ Report Number:
  CA25-3699j ; GIRS-2024-01
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; California
• Edition:
  Final Report: May 2020 - April 2025
• Corporate Publisher:
  California. Department of Transportation. Department of Research, Innovation and System Information
• Abstract:
  In this study, nonlinear deformation analyses (NDA) and equivalent-static analyses (ESA) approaches were evaluated for a model bridge embankment that was underlain by a non-liquefiable crust layer, a liquefiable medium dense sand layer, and a non-liquefiable deep dense sand layer. The embankment and underlying ground conditions were selected to represent a scenario when a deformation analysis would be required to assess the impacts of earthquake-induced liquefaction of the ground. Four geometry conditions were considered in the study that differed in the dimensions of the medium dense sand and overlying crust. In addition, two densities of the medium dense sand were considered to assess the impacts of different liquefaction responses. Two earthquake scenarios applicable to California were used, one representing a near-field earthquake scenario and the other representing a far-field earthquake scenario. Based on the results from the NDA and ESA, it was highlighted that both analysis approaches were able to differentiate similarly between the different model geometries, different medium dense sand densities, and different earthquake scenarios. The magnitude in deformation predicted from the NDA and ESA, however, varied widely. The ESA tended to underpredict displacement when displacements are small and overpredict displacements (i.e., predicting flow failure) when displacements are large. From a practical design standpoint, then, from these results, the ESA appeared sufficient for differentiating between extreme conditions (e.g., deformations very small or very large), but the magnitude of the results themselves lacks accuracy, at least compared to the NDA.
• Format:
  PDF
• Funding:
  65A0780
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:00a14df214603eb397bbabce6900859724df127527a7a171212421c434cf805bc9e2750f18bea844ec529c97f6326b1629d178e041455d97d126d031824b0e65
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/89080/dot_89080_DS1.pdf
• File Type:
  [PDF - 3.42 MB ]