Effect of shaking intensity on interactive behavior of soil-pile group foundations in liquefiable soil during shaking table tests

Shaking table tests were performed to evaluate the dynamic interactive behavior of soil and pile group foundations in a liquefiable ground. The test results give detailed information on the pile acceleration time histories, distributions of bending strain within the pile group as well as the ground response and pore water pressure generation in the soil around the piles. Slight liquefaction occurs under moderate shaking while complete liquefaction occurs under strong shaking. The soil accelerations at the ground surface are both amplified at moderate and strong shaking. Accelerations of the pile near tip and superstructure are slightly amplified under both moderate and strong shaking, with larger amplification factors occurring in the latter case. The accelerations of pile cap are de-amplified under moderate shaking and significantly amplified under strong shaking. For the pile, the maximum bending moment occurs at the connections between pile and cap. Regarding the pier bottom, the maximum bending moments are almost equal to those of the pile to cap connections. The above results may contribute to the deep understanding of soil-pile-structure interaction in liquefiable ground.