Lateral Bearing Capacity of Embedded Pile Foundation under Sinusoidal Excitation

影响建筑物地下结构抗地震力的因素有三个，即(a)前后土压力，(b)侧壁侧面摩擦，(c)桩的弹性刚度。本研究旨在明确埋置基础的侧向承载力，分析地震作用下的土压力特征。为此，采用振动土箱进行了约束条件下的正弦激励试验，并采用拟三维模型进行了有限元模拟分析。对不同条件下的解析法参数进行了研究。通过试验和参数分析，可以很容易地通过基础和土的特性来解释预埋基础的横向承载力。当结构放大幅度大于地基放大幅度时，土压力侧力分配比大于50%，桩侧力分配比减小到25%左右。侧向面摩阻比约为10 ~ 30%，与上部结构关系不大。

There are Three factors that affect resistance of the underground structure of building against seismic force, that is, (a) front and back earth pressure, (b) lateral face friction on the side walls and (c) resilient rigidity of piles. This study aims at clarifying the lateral bearing capacity of embedded foundation, and analyzing the characteristics of earth pressure in earthquake. To study, sinusoidal excitation tests were made under the restricted conditions using an oscillating soil bin, followed by the finite element analysis simulated with pseudo-three-dimensional models. The study of parameters was also made in analytical method under different conditions.From these tests and parameter analysis, it was found that the lateral bearing capacity of embedded foundation could be easily explained through the behavior of both foudation and soil. When the amplification magnitude of the structure was larger than that of the ground, the lateral force distribution ratio of the earth pressure exceeded 50% and that of the piles decreased to about 25%. Lateral face friction ratio is about 10-30% and does not significantly depend on the superstructure.