摘要
隧道暗挖施工常引起地层移动和变形,导致周围构筑物发生移动和变形,影响运营安全。文章以新建北京轨道交通新机场线一期工程下穿北京特大桥工程为案例,对照评估标准对暗挖施工及运营中可能出现的桥梁基础变形及桩基受力变化开展定量安全评估分析。为评估暗挖隧道施工及运营对既有铁路特大桥运营安全的影响,建立MIDAS GTS有限元模型并模拟关键施工工序,对既有铁路桥梁沉降变形及结构受力进行安全评估,并从设计层面给出优化建议。研究结果表明,隧道CRD法施工结合初支背后深孔注浆+外部排桩隔离的防护方案对保证既有桥梁结构及运营安全是可行且有效的,可为同类工程建设提供参考和借鉴。
Tunnel undercutting construction often causes ground movement and deformation, which causes the movement and deformation of the surrounding structures and affects the operation safety. Taking the new Beijing rail transit new airport line phase 1 project undercrossing Beijing super-large bridge project as an example, this paper carries out quantitative safety assessment analysis on the deformation of the bridge foundation and the stress change of pile foundation that may occur in the construction and operation of undercutting construction according to the assessment criteria. In order to evaluate the influence of the tunnel undercutting construction and operation on the operation safety of the existing railway bridge, the MIDAS GTS finite element model is established and the key construction procedures are simulated. The safety assessment of the settlement deformation and structural stress of the existing railway bridge is carried out, and the optimization suggestions are given from the design aspect.The research results show that the tunnel CRD method construction combined with the protection scheme of deep hole grouting behind the initial support + external row pile isolation is feasible and effective to ensure the safety of the existing bridge structure and operation, which can provide reference for similar engineering construction.
作者
刘欢
LIU Huan(China Railway Design Corporation,Tianjin 300308,China)
出处
《工程技术研究》
2023年第3期24-26,共3页
Engineering and Technological Research
关键词
隧道暗挖
下穿铁路桥
有限元模拟
安全评估
tunnel undercutting
underpass railway bridge
finite element simulation
safety assessment
