城市地铁TBM隧道掘进诱发既有建筑物变形的空间属性效应

Influence of TBM tunnel excavation at different positions on buildings

针对城市地铁全断面硬岩隧道掘进机(tunnel boring machine,TBM)隧道掘进诱发既有建筑物沉降变形的问题,考虑隧道下穿城市建筑物群实际工况的复杂性,以青岛地铁1号线小北区间段硬岩地层TBM隧道掘进下穿既有建筑物群为实际工程背景,采用数值计算分析方法,建立TBM隧道掘进连续下穿多座既有建筑物的三维力学计算模型,综合研究TBM隧道单洞掘进对单一建筑物变形的空间属性效应;从工程建设实际出发,系统研究空间属性对于TBM隧道双洞掘进连续下穿多座紧邻既有建筑物过程中诱发地层与既有建筑物的应力应变状态。研究结果表明:隧道埋深越浅,则建筑物受隧道开挖的沉降速率越大;在双线隧道开挖中,埋深越浅,建筑物受横向距离较近的隧道开挖影响占比越大,隧道埋深越大受双隧道叠加影响越大。隧道下穿不规则建筑物时对建筑物转角处以及在大尺寸建筑物附近的小型建筑物影响较大,在实际施工中需要进行监测。

In view of the settlement and deformation of existing buildings induced by TBM(tunnel boring machine)tunnel excavation of urban subway,considering the complexity of the actual working conditions of tunnel undercrossing urban buildings,taking the TBM tunnel tunneling in hard rock stratum of Xiaobei Section of Qingdao Metro Line 1 as the actual engineering background,the numerical calculation method was adopted to establish the continuous tunneling of TBM tunnel through several existing buildings.Based on the engineering construction practice,the spatial attribute characteristics of TBM tunnel were systematically studied.The stress-strain state of ground layer and existing buildings induced by TBM tunnel double tunnel driving under existing buildings were studied systematically.The research results showed that the shallower the tunnel depth was,the greater the settlement rate of the buildings affected by the tunnel excavation.In the excavation of double track tunnel,the larger the proportion of buildings affected by the excavation of the tunnel with shorter transverse distance,the greater the tunnel buried depth,the greater the influence of the superposition of double tunnels.When the tunnel passed through the irregular building,it had great influence on the corner of the building and the small building near the large-scale building,so it needed to be monitored in the actual construction.