平面应变下结构性对黄土基坑稳定性的影响

鉴于以往很少考虑黄土结构性对基坑开挖的影响，针对目前普遍存在的基坑稳定性问题，开展室内平面应变条件下的真三轴试验，建立黄土结构性与强度之间关系，通过FISH语言将其引入到基坑开挖数值模拟中，分析结构性对基坑开挖的影响。研究表明，结构性参数与强度指标的变化规律与以往研究结果基本一致，表现为结构性参数与黏聚力呈双曲线关系，但参数略有不同，其受摩擦角的影响较小；结构性影响下基坑侧壁出现明显滑带，且此时连续墙的侧向位移大于不考虑其影响时的位移，坑底隆起量亦如此。研究结果对黄土基坑工程的设计和施工具有一定的指导意义。

Study of influence of structural property on stability of foundation pit under plane strain condition

The influence of structural property on foundation pit excavation is rarely considered. The foundation pit stability problem is widespread. The paper does the indoor triaxial test under the plain strain, and establishes the contact between the loess structural property and the strength, then introduces it into numerical simulation by FISH language; finally analyzes the influence of structural property on the stability of foundation pit. The study results show that the variation between structural parameter and strength indicators is consistant with previous findings. It is shown that the relationship between structural parameter and cohesive force is hyperbolic, but the parameters are slightly different. The influence of friction angle on the structural property is so small. Meanwhile, the paper finds the that significant slip zone appears in the pit sidewalls; and lateral displacement is greater than the continuous wall without considering its impact displacement; the foundation pit bottom uplift amount is also true. The results have a certain significance to design and construction of the loess foundation foundation pit engineering.