基坑被动区拱形加固布置的拓扑优化及数值分析

摘要

The layout forms of solid-web and lattice reinforcement are usually adopted in the reinforcement for the passive zone of foundation pit, while the feasibility of arch layout, a new type of reinforcement form, needs to be verified. We fist apply ANSYS software to conduct topology optimization to the reinforcement form, and the result shows that the arch reinforcement is the optimal form. Furthermore, 2D finite element simulation analysis shows that arch structure can save more materials than lattice form under the same pile deformation. Based on a practical case, the simulation and monitoring results confirmed that the multi-arch structure can significantly reduce the construction material for same pile deformation compared with traditional forms, which provides theoretical and practical guidance for arch reinforcement in passive zone of foundation pit.%在采用水泥搅拌桩加固被动区土体的工程实践中,常见的加固形式有实腹式和格构式,而拱形布置作为一种新型的加固形式,其合理性及优势有待验证. 首先采用ANSYS软件对加固布置形式进行了拓扑优化,发现拱形为受力最优形式. 进一步的二维有限元计算表明,在桩体位移相同情况下,拱形比格构式能节省更多材料. 以某基坑工程为例开展了实例研究,数值模拟及监测结果证实,相较于传统实腹式布置,多拱结构在控制桩体位移的同时,能大幅减少材料用量.