隧道盾构法施工引起周围土体附加应力分析

结合弹性力学Mindlin解，运用边界单元法，推导了施工过程中盾构正面推力和盾壳与土体之间的摩擦力引起的周围土体附加应力计算公式。根据土体损失的空间分布规律，应用镜像法原理，推导了土体损失产生的附加应力计算公式。将正面推力、摩擦力和土体损失引起的附加应力进行叠加，得到盾构推进过程中周围土体总的附加应力计算公式。以上海某隧道工程为例，分析了正面推力、摩擦力、土体损失及共同作用引起附加应力的分布规律及对周围环境的影响，为保护盾构推进一定范围内的建（构）物提供了依据。

Analysis of superimposed stress of surrounding soil due to shield tunneling

By using Mindlin solution and boundary element method, the calculation formulas of superimposed stress of surrounding soil induced by bulkhead pressure and friction force during the propulsion of shield tunneling are deduced. According to the space regularities of distribution of ground loss and by image method theory, the calculation formulas of superimposed stress are deduced. And combining the above three part of stress, the total superimposed stress induced by shield tunneling is obtained. Finally, combined with the practice of subway engineering in Shanghai, the distribution law of the superimposed stress caused by bulkhead pressure, friction, ground loss and their combined effect is analyzed. And the analytical results can provide gist for the protection of surrounding construction during the propulsion of shield tunneling.