钙质砂中单桩水平承载特性模型试验研究

通过室内模型试验研究钙质砂地基中桩基的水平承载特性，分析桩长对桩顶位移、桩顶转角、桩身弯矩以及桩侧土体压力分布的影响，并与福建标准砂地基中的模型桩进行了比较。试验结果表明：桩长对水平承载特性具有显著影响；增加桩长能明显提高单桩水平极限承载力，桩身变形逐渐由刚性转动转变为弯曲变形；弯矩沿桩身的分布范围由全段分布转变为集中在桩身上半部分；桩侧土压力主要分布在迎土侧的上部土层中，土体压力随着水平荷载的增加而发生明显变化；在低应力水平下，钙质砂中单桩水平承载力要大于标准砂中桩基承载力，钙质砂在较高应力水平下的模型试验有待进一步探究。

Horizontal loading model test of single pile in calcareous sand

Through a series of model tests in laboratory, the horizontal bearing characteristics of the pile in the calcareous sand foundation were investigated. The influence of the pile length on the pile top displacement, the rotation of the pile head, bending moment of the pile body and the distribution of the pile side soil pressure were analyzed. In addition, it is compared with model piles in silica sand (Fujian standard sand). The test results show that the horizontal displacement-load curve of the model pile in the calcareous sand is abrupt, and the pile length has a significant influence on the horizontal bearing characteristics. Increasing the pile length can significantly increase the ultimate horizontal bearing capacity of model pile, and the pile deformation gradually changes from rigid rotation to bending deformation. The distribution range of the bending moment along the pile body is changed from the whole pile length to half. The soil pressure on the side of the pile is mainly distributed in the upper soil layer on the soil-facing side, and the soil pressure changes significantly with the increase of the horizontal load. Under low stress levels, the horizontal bearing capacity of a single pile in calcareous sand is greater than that in silica sand. The model test of calcareous sand under higher stress levels needs to be further explored.