基于Mindlin解的隧道施工引发的附加荷载及接收井变形分析

Analysis of additional load and receiving shaft deformation caused by tunnel construction based on Mindlin solution

对盾构机施工引起的接收井的受力和变形进行分析。首先,基于Mindlin解推导出盾构机临近接收井时各施工因素引起的附加应力和简化成竖向地基梁的围护结构变形计算公式;其次,计算分析某地铁盾构附加推力、盾壳摩阻力、盾尾注浆压力引起的深度为13 m时刀盘平面和隧道轴线上的附加荷载、接收井墙面上的附加荷载、不同深度下盾构机距接收井5 m和10 m时围护结构的变形情况并通过数值模拟进行验证。研究结果表明:掌子面附加推力和盾壳摩阻力导致接收井围护结构变形在竖向分布为先增后减,附加注浆压力以刀盘为中心呈反对称分布;在对围护结构变形的影响因素中,盾壳摩阻力影响最大,掌子面附加推力的影响次之,盾尾附加注浆压力的影响可以忽略。

The force and deformation of the receiving shaft caused by the construction of the shield machine were analyzed.Firstly,based on the Mindlin solution,the additional stress caused by various construction factors were derived when the shield machine approached the receiving shaft and the calculation formula for the deformation of the enclosure structure was simplified as a vertical foundation beam.Secondly,the additional load on the cutter head plane and the tunnel axis and the additional load on the wall of the receiving shaft were calculated and analyzed when the depth is 13 m caused by the additional thrust,the friction resistance of the shield shell,and the grouting pressure of the shield tail based on a certain subway,and it was verified by numerical simulation.The results show that the additional thrust of the tunnel face and the frictional resistance of the shield shell cause the deformation of the receiving shaft enclosure structure increase first and then decrease in the vertical distribution,and the additional grouting pressure is distributed antisymmetrically in the center of the cutter head.Among the factors affecting the deformation of the enclosure structure,the frictional resistance of the shield shell is the most important,followed by the additional thrust of the tunnel face,and the additional grouting pressure at the tail of the shield can be ignored.