软土地区双基坑开挖变形分析及其对既有地铁车站结构的影响  

Analysis of Excavation Deformation of Double Foundation Pit in Soft Soil Area and Its Influence on the Structure of Existing Metro Station

作　　者：张巧慧[1] 姜小磊 ZHANG Qiaohui;JIANG Xiaolei(Shaanxi Railway Institute,Weinan 714000,China)

机构地区：[1]陕西铁路工程职业技术学院,陕西渭南714000

出　　处：《粉煤灰综合利用》2021年第6期51-57,共7页Fly Ash Comprehensive Utilization

摘　　要：本文利用FLAC 3D数值计算软件建立了软土地区双基坑开挖的数值计算模型,分析11号线和枢纽站基坑开挖过程中的地表沉降和桩体水平位移,研究双基坑开挖对既有车站结构位移的影响规律。研究结果表明:(1)数值计算结果与实际监测结果的吻合度高,可用于软土地区双基坑开挖对既有结构影响规律分析;(2)11号线基坑和枢纽站开挖基坑周边土体的沉降规律基本相同,最大沉降分别为8.0 mm和19.9 mm;(3)11号线基坑开挖过程中,东侧桩和西侧桩的最大水平位移分别为10.8 mm和11.9 mm,由于在枢纽站基坑开挖时11号线车站主体结构尚未施工,桩体最大水平位移分别增加6.0 mm和6.9 mm;(4)11号线车站基坑开挖时,5号线和1号线车站主体结构以隆起为主,而枢纽站基坑开挖时,5号线和1号线车站主体结构以沉降为主。FLAC 3D numerical calculation software was used to establish a numerical calculation model for the excavation of double foundation pits in soft soil areas in this paper.On-site actual engineering monitoring data is compared and analyzed,and on this basis,the influence of the excavation of double foundation pits on the displacement of the existing station structure is studied.The research results show that:(1)The numerical calculation results are in good agreement with the actual monitoring results,which can be used to analyze the influence of double foundation pit excavation in soft soil areas on the existing structure;(2)the settlement laws of the surrounding soil around the foundation pit of Line 11 and the excavation of the junction station are basically the same,with the maximum settlements being 8.0 mm and 19.9 mm respectively;(3)during the excavation of the line 1 foundation pit,the maximum horizontal displacements of the east side pile and the west side pile were 10.8 mm and 11.9 mm,respectively.As the main structure of the Line 11 station has not been constructed when the foundation pit of the hub station is excavated,the maximum horizontal displacement of the pile will increase by 6.0 mm and 6.9 mm,respectively;(4)During the excavation of the station foundation pit of Line 11,the main structure of the station of Line 5 and Line 1 was mainly uplifted,and when the foundation pit of the hub station was excavated,the main structure of the station of Line 5 and Line 1 was mainly due to subsidence.

关 键 词：软土地区 双基坑 地铁车站 变形 结构 

分 类 号：U231[交通运输工程—道路与铁道工程]