穿越采空区桥隧工程危害效应分析及对策

Numerical analysis of hazard effects and protection measures of highway tunnel and bridge crossing mined-out regions

青岛—银川高速公路的康家沟大桥与庙梁隧道下伏康家沟煤矿采空区,为确保桥隧工程的安全,基于M IDA S/GTS有限元程序构建了FLAC3D三维计算模型,对分期采矿形成地下采空区进行注浆处治,对桥隧工程施工过程中地表变形响应、隧道初衬结构、桥梁和墩台的变形及受力特征等进行数值模拟分析,揭示了不同工况条件下的地表变形程度,确定了地表沉陷盆地特征,对隧道初衬结构和桥梁墩台进行了变形和受力关键部位的预测分析,并提出了有效工程对策。研究成果对指导类似桥隧工程设计和施工有重要指导意义。

The Kangjiagou mined-out regions are under the Kangjiagou bridge and Miaoliang tunnel project in Liulin section of Qingdao-Yinchuan highway. In order to ensure the project safety, the three-dimensional computation models were built using the MIDAS/GTS finite element program, and numerical simulation analyses of the ground deformation response, and the tunnel lining and the bridge structural deformation as well as their structural force using FLAC^3D were performed. The processes were generated in the step- by-step mining region for the treatment after mining coal in Kangjiagou. The double-layered Miaoliang tunnels were excavated and Kangjiagou bridge was constructed. The surface deformations under different working conditions were revealed, and the ground subsidence basin characteristics and the central subsidence position were determined. Besides, the deformations and forces of key hearing parts of the tunnel lining and the bridge were predicted, then the corresponding countermeasures and suggestion were given. The results are of great importance to the design and construction of similar bridges and tunnels.