三管隧道开挖对周边构筑物影响分析研究

为保证三重隧道施工安全,在建立复杂三维数值模型的基础上,对地铁盾构隧道与铁路出入线隧道施工进行模拟,获取施工过程中地铁隧道所引起的轨道沉降位移曲线。通过分析施工过程中近接地下空间的位移响应趋势,判断地铁盾构隧道、铁路隧道对周边桥桩与地表铁路轨道的影响。同时,对于采用CD法与预留核心土台阶法两种工法进行对比研究,并且提出此两种方法对地表铁路股道的影响。根据计算结果得到隧道开挖施工对股道影响范围,为宽44 m、纵向36.5 m的区域。根据影响范围区域,提出监测方案。根据监测可知,沉降最大值仅为0.5 mm,采用目前的设计方案施工可以保证成花铁路的运营安全。研究所得结论对复杂地下空间中的多重隧道施工具有一定的参考价值。

Influential Analysis of Triple Tunnel Construction on Adjacent Structures

To ensure the safety of the triple tunnels,a three-dimensional numerical model is developed to simulate construction process of subway and railway tunnels and to obtain metro tunnel construction induced track subsidence curve based on numerical simulation. By analyzing the displacement response during tunneling construction, the influences generated by metro shield tunneling and NATM construction on adjacent bridge piers and groundrailway tracks are analyzed. Meanwhile,comparison is made between CD method and core soil bench method. The impacts of the two methods on the ground railway tracks are illustrated. Based on numerical simulation results,the tunneling influential range is defined as 44 m in width and 36. 5 m in longitudinal direction. Based on the influential range,field monitoring scheme is put forward. The field observation results show that the maximum settlement is only 0. 5 mm,and the construction with current design scheme can ensure the safety of existing structures. The research results are of certain reference value for multiple tunnel construction in complex underground space.