隧道竖井施工对地下管线影响的数值模拟

Numerical Simulation for the Effect of Tunnel Shaft Construction on Buried Pipelines

研究目的:研究武汉长江隧道施工对地下管线的影响,对于确保工程的安全实施至关重要。建立江北竖井地下连续墙、土体与地下管线变形耦合作用的三维有限元分析模型,分析不同开挖步骤、不同管材、不同地下管线埋深、离基坑的不同距离、不同管径、壁厚对地下管线位移的影响。研究结论:以武汉长江隧道江北竖井施工为例,通过建立计算模型和对不同开挖步骤、不同管材、不同管径、不同地下管线埋深、离基坑不同距离的分析,管线位移随开挖深度增加而增大,头两步开挖对管线位移的影响起决定性作用,在前二步开挖时要严密监测施工对管线的影响;由于受到地下连续墙的抑制作用,地下管线存在着端部效应问题,离基坑越近,其端部效应越明显,端部效应改变了管线的位移形态;管线外径和壁厚对其位移的影响不显著;多种管线并存时,其相互影响不显著。

Research purposes： Investigating the effect of Wuhan Yangzte River tunnel construction on buried pipelines is very important to ensure the construction safety. 3 - D FEM is applied to model the deformational coupling effect for the north side shaft diaphragm, surrounding soil and buried pipelines. Construction effect on pipe deformation is analyzed in terms of excavation steps, pipe material, buried depth, distance to pit, pipe diameter and wall thickness of pipe. Research conclusions：Take the north side shaft construction of Wuhan Yangzte River tunnel for example, this paper analyzes the construction effect in terms of excavation steps, pipe material, buried depth, distance to pit, pipe diameter and wall thickness of pipe. The result indicates that the pipeline displacement increases as excavation depth. The magnitude of the displacement is mainly determined by the first two excavation stages. The first two excavation stages should be strictly monitored ; for the sake of diaphragm wall, end - effect exists on the pipeline. End - effect becomes distinct as close to the pit. And the displacement mode is changed for the sake of end - effect;outer diameter and thickness of pipeline has no distinct effect on pipeline displacement; multiple types of pipelines have no distinct effect on each other when they exist together.