长距离叠交隧道施工过程三维有限元模拟研究

浦东南路站～南浦大桥站区间隧道工程全长2000米，在浦西段位于南浦大桥桩基间施工，为确保线型同时避让南浦大桥桥桩，采用长距离叠交隧道施工工艺，叠交距离达437．7米，为国际罕见。为了优化盾构施工的各项施工参数，有效进行施工过程控制，完善施工技术方案，保证科学合理、安全优质地完成隧道的设计与施工，同时为以后叠交隧道工艺及隧道线路规划、设计的优化提供借鉴，为类似工程施工提供经验积累，对盾构隧道长距离叠交施工进行三维非线性静力应力应变分析。通过模拟研究建立了三维有限元模型，经过计算分析，国内首次分析了长距离叠交过程中后建隧道盾构施工对已建隧道的影响，摸索出隧道推进过程中的周围土体的移动规律、地表面水平位移及地面沉降规律、已建隧道管片位移和变形及应力变化规律。

3D FEM Analysis on Construction Process of Long Distance Overlap Technique

The interval tunnel of Pu Dong Rd(S)~Nan Pu Bridge, added up to 2 km in length, is designed to pass through the group piles under Nan Pu Bridge. In order to dodge those piles, the long distance overlap technique is utilized in construction process. The overlapped tunnels amount to 437.7m and such a long distance is rare in the world. To optimize working factors, improve working plan on techniques, so as to accomplish the project's designing and construction tasks in a scientific and rational way, and also to gain enough experiences for similar projects in future at the same time,3D non-linear static analysis was accomlished to study the stress strain rule on construction stage and, was analyzed the impacts on constructed tunnel by the tunnel under construction in overlapped-tunneling process. The rules of soil movement, ground settlement and axis displacement as well as distortion of adjoining tunnel during the advance of shield were worked out.