Abstract: 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.

Key words: plane strain, structural property, foundation pit, stability