基坑开挖对在建道路的影响及加固措施

Study on Influence of Foundation Pit Excavation on Road under Construction and Reinforcement Measures

目的 分析基坑开挖对围护结构和在建道路的影响,探究保证基坑和道路结构稳定的加固措施。方法 以杭州市某基坑与在建道路交叉施工为工程背景,进行三维有限元建模,对基坑开挖和道路振动施工全过程进行模拟。结果 在道路振动施工作用下,基坑围护结构最大水平位移为5.26 mm;基坑开挖完成后,基坑围护结构的水平变形和道路的竖向变形均较大,须采用加固措施控制围护结构和道路的变形。结论 在基坑全部卸荷后,采用斜撑和增加支撑预应力综合加固措施与未采用加固措施相比,CX20监测点的最大水平位移和道路最大沉降分别减小了28.97%和35.34%,变形控制效果显著。

In order to analyze and explore the influence of foundation pit excavation on the road under construction and the reinforcement measures that can ensure the stability of foundation pit and road structure,a 3-D FE model was established based on the practice of the simultaneous construction of a foundation pit and a road in Hangzhou.Under the action of road vibration,the maximum horizontal displacement of foundation pit envelope is 5.26 mm.After the foundation pit excavation,the horizontal deformation of the envelope and the vertical deformation of the road are large,and the reinforcement measures should be adopted.The results show that the maximum horizontal displacement of CX20 monitoring point and the maximum settlement of the road are reduced by 28.97%and 35.34%for the comprehensive strengthening measures of diagonal bracing and increasing brace prestress are adopted,respectively,when compared to without strengthening measures.The deformation control effect is remarkable.