Centrifuge Seismic Test on Seismic Behavior of Pile Group in Liquefiable Soil: Fid-Bau Portal

Centrifuge Seismic Test on Seismic Behavior of Pile Group in Liquefiable Soil

Hsieh, Meng Hsiu / Hung, Wen Yi / Lee, Chung Jung

A series of grouped-model piles (2×2) centrifuge shaking table tests at an acceleration of 80 g was conducted to simulate seismic responses of a grouped-piles embedded in liquefiable sandy soil subjected to different magnitudes of earthquake loading. The tested grouped-piles connected with a pile cap are used to support 4 sets of model dry storage tank.Different test conditions including elevations of pile cap, elevations of ground water table, and dry and saturated sand beds all are reported in the study. Sensors (i.e., strain gauges along the depths of pile for measuring the bending moments, accelerometers for measuring the accelerations at different depths, LVDTs and pore water pressure transducers) densely instrumented in the piles and the surrounding soils provide valuable information for examining their evolution at various degrees of liquefaction. The magnitudes of bending moment along pile depths would increase with the increases of base shaking. The lowest bending moments were measured for the grouped–piles with the pile cap embedded in the dry sand bed while the largest lowest bending moments for the grouped–piles with the pile cap embedded in the saturated sand bed with the water table at the surface. The test results can be used to validate the results derived from the numerical simulation.