SHAKING TABLE TEST AND NUMERICAL SIMULATION FOR SEISMIC SOIL-PILE-BRIDGE STRUCTURE INTERACTION IN LIQUEFIABLE GROUND

摘要

Here the investigation through shaking table test involving in the liquefaction characteristics of unfree ground and seismic response of single-pile-supported bridge structure is presented. The shaking table test, taking the destructive Shengli bridge in 1976 Tangshan earthquake as its prototype, was performed using the laminar shear box with depth of 2 m and plan dimensions of 2 m and 1.5 m, and the soil profile consisted of the lower level liquefiable saturated loose sand overlying non-liquefied silty clay crust. Galvanized iron wire and micro-concrete single-pile was used in the test. Bridge superstructure was modeled as the iron mass. The model was tested with a series of El Centro earthquake of varying level of shaking. The large-scale shaking table test involved intense shaking that lead to a significant degradation of strength and stiffness of soil due to liquefaction. Representative data that characterize important aspects of soil-pile interaction mechanics in liquefied ground were presented. The test results are analyzed and simulated in detail with FORTRAN program.This paper provides an insight into the numerical simulation of seismic soil-pile-structure interaction (SSPSI) in liquefiable ground studied in a shaking table facility. The numerical simulation of the complete soil-pile-bridge structure in liquefiable ground is conducted according to shaking test table using the finite element method. The matching of the experimental and numerical responses in the time domain is satisfying. Many important aspects of SSPSI in liquefiable ground that are apparent in the experiment are captured by the numerical simulation.