土岩复合地层中CRD隧道施工的变形监测与风险控制

发布时间：2019-06-06 18:23

【摘要】：以典型城市土岩复合地层中的某地铁CRD(交叉中隔壁法)隧道为依托,通过分析洞内、外变形监测数据,总结变形规律,对该隧道风险进行有效控制。研究结果表明:洞内、外变形量的60%以上是由上2层导洞开挖引起的;隧道开挖引起的地表沉降槽特征较为明显,地表最大沉降点位于隧道中心线上方偏左;隧道掌子面开挖的横向影响明显,范围约为60m。洞内变形监测的分析指标以拱顶沉降为主,水平收敛为辅;拱顶下沉曲线分段组成,总体呈台阶状下降。综合变形监测分析和施工经验认为:施工中应着重控制上2层导洞初期支护结构的及时闭合;相邻导洞掌子面间距控制在15~20m;台阶长度控制在5m以内,及时封闭仰拱,闭合成环,可有效地控制洞内、外变形和保证初期支护结构稳定性。
[Abstract]:Based on a subway CRD tunnel in typical urban soil-rock composite strata, the risk of the tunnel is effectively controlled by analyzing the monitoring data of deformation inside and outside the tunnel and summing up the deformation law. The results show that more than 60% of the internal and external deformation of the tunnel is caused by the excavation of the upper two-story guide tunnel, and the characteristics of the surface subsidence trough caused by the tunnel excavation are obvious, and the maximum settlement point of the surface is left above the center line of the tunnel. The transverse influence of tunnel face excavation is obvious, and the range is about 60 m. The analysis index of deformation monitoring in the cave is mainly the settlement of arch roof, supplemented by horizontal convergence, and the subsidence curve of arch roof is divided into sections, which is generally step down. According to the comprehensive deformation monitoring analysis and construction experience, the timely closure of the initial supporting structure of the upper two-story guide tunnel should be controlled in the construction, and the distance between the palms and surfaces of the adjacent guide holes should be controlled at 15 m. The step length is controlled within 5 m, the inverted arch is closed in time and the ring is closed, which can effectively control the deformation inside and outside the hole and ensure the stability of the initial supporting structure.
【作者单位】：北京工业大学城市与工程安全减灾教育部重点实验室;
【基金】：北京市教育委员会科技计划项目(KM200910005012) 城市与工程安全减灾教育部重点实验室项目(2013ZD01)资助
【分类号】：U456.3

【相似文献】