中文摘要：

采用三维有限元方法对新建隧道盾构下穿施工过程进行了动态模拟,分析了新建隧道盾构正交下穿施工对既有隧道位移、应力的影响;进而探讨了不同的隧道覆土厚度、隧道间相对距离及土体强度下,新建隧道盾构正交下穿施工对既有隧道位移的影响。结果表明：新建隧道盾构正交下穿施工引起既有隧道位移方向朝向新建隧道方向发展,既有隧道位移以纵向沉降为主,沉降曲线符合正态分布;盾构下穿引起的既有隧道正应力变化较大;隧道覆土厚度、隧道间相对距离和土体强度对隧道间相互作用有较大影响,应引起足够的重视。

英文摘要：

By means of 3D-FEM,the construction process of undercrossing construction is simulated and the influence of shield tunneling on settlement of the ground surface and displacement and internal forces of the existing tunnel are analyzed.Then,the influence of undercrossing construction on displacement of the existing tunnel under different covering soil condition is studied.The results show that the displacement of the existing tunnel caused by shield tunneling points to the new tunnel,the major of the existing tunnel displacement is longitudinal settlement which is normal distribution,and the normal stress of the existing tunnel have a great change.The thickness of overlay soil,the net distance between the tunnels and the compression modulus of soil have great influence on the interaction between tunnels.