Abstract:To accurately analyze the seismic site effect of circular underground cement—soil pile foundations and improve the seismic performance of buildings, in this study, we used ABAQUS finite element software to analyze the seismic effect on circular underground cement—soil pile foundations with different random parameters. Specifically, we analyzed the parameters used in the calculation, the geological conditions of the site, and the equivalent composite soil parameters. Using a simplified model of a two-dimensional composite modulus, we discuss the influences of the reinforcement depth, a newly built structure on the foundation, the topography of the underlying bedrock, and some random parameters (e.g., modulus of cement soil, seismic attributes, and different scenes) on the seismic site effect. The experimental results show that the peak acceleration response on the circular underground cement—soil pile foundation decreases with increased reinforcement depth of the cement—soil pile and composite modulus, and is significantly lower than that on a free field. A new structure on the foundation experiences a strong disturbance in the ground motion characteristics around the foundation, and the interference amplitude and area have a high correlation with the structure scale. We found a certain correlation between the bedrock terrain at the bottom of the foundation and the ground motion characteristics of the upper foundation. The influence of soil conditions on the seismic effect of the composite foundation is great, whereas the influence of the pile modulus is relatively small.
