关键词: 基坑加深开挖, 复合桩锚支护结构, 有限元强度折减法, 基坑变形, 基坑稳定性

Abstract: We introduce the composite pile-anchor support structure that is used to reinforce a foundation pit deeper excavation project. The deformation of the composite pile-anchor retaining structure and the stability of foundation pit are studied through the finite element numerical simulation method. The results show that the maximum horizontal displacement of new piles and the old one decrease with the increasing of old and new pile spacing; with the increasing of the height of new pile, the maximum horizontal displacement of new piles increases, while the old ones basically remain the same. The stability factor increases with the increasing of old and new pile spacing, while it almost has no relation with the height of new pile. The old and new pile spacing has control effect on the slide surface pattern. For the reinforcement of the foundation pit deeper excavation, the spacing increase of old and new piles and decrease of new pile height can effectively control the deformation. The monitoring data shows that the strengthening method of the foundation pit support structure is feasible, which has reference value.

Key words: foundation pit deeper excavation, composite pile-anchor retaining structure, FEM strength reduction method, deformation of foundation, stability of foundation pit