隧道施工引起的地表变形数值模拟

研究目的:评估石桥头浅埋隧道在采用不同施工方法和加固措施施工时对地表建筑物的影响。研究方法:对穿越城区浅埋的石桥头隧道在采用三台阶临时仰拱法和双侧导坑法爆破施工时的地表变形进行三维有限元数值模拟。研究结果:采用三台阶临时仰拱法时,隧道第一步开挖对地表的沉降影响较大,采用双侧壁导坑法时,第五和六步开挖沉降变化较大。地表倾斜、地表弯曲曲率与水平变形分析表明,双侧壁导坑法优于三台阶临时仰拱法。研究结论:针对石桥头隧道,建议采用较保守的双侧壁导坑法进行施工,并辅以必要的支护(小导管、长管棚等)和加固(防护桩、地表注浆等)措施,控制地表沉降和变形,确保地表建筑物的安全。

Simulation of Numerical Values of Surface Deformation Caused by Tunnel Construction

Research purposes: The purposes are to make an evaluation of the influence on the surface buildings by construction of Shiqiaotu shallow buried tunnel with different construction methods and reinforcement measures.Research methods:The simulations with 3D finite-element numerical values are made for the surface deformation caused by the blast for construction of Shiqiaotu Shallow buried tunnel with triple steps temporary inverted arch method and two-side pilot tunnel method.Research results:The excavation of tunnel in first step makes big influence on the surface settlement when triple steps temporary inverted arch method is adopted and excavations of tunnel in the fifth and sixth steps make big changes of settlement when two-side pilot tunnel method is adopted.The analyses of surface incline,surface curvature and level deformation show two-side pilot tunnel method is superior than triple steps temporary inverted arch method.Research conclusions:For construction of the Shiqiaotu Tunnel,it is proposed to adopt two-side pilot tunnel method along with necessary support and reinforcement measures for controlling the surface settlement and deformation and guaranteeing the safety of surface buildings.