中文摘要：

针对基坑开挖直接引发临近运营地铁盾构隧道不均匀变形的计算问题,为克服将盾构隧道视为等效均质弹性地基梁的传统算法的不足,提出了能量计算法。采用Mindlin基本解计算基坑开挖引起的隧道附加应力,并通过坐标变换使其可以考虑隧道与基坑轴线存在夹角的情况;将盾构隧道衬砌环视为由剪切弹簧连接的弹性地基短梁,并结合基坑开挖会导致盾构隧道发生环间错台的情况,建立隧道变形计算模型;利用最小势能原理建立变分控制方程,求解隧道的竖向、水平位移和环间错台量。将本文计算结果与现场实测数据和弹性地基梁法计算结果对比可知,本文算法的计算结果与现场实测数据吻合更好,而且计算效率更高。

英文摘要：

In allusion to the problem for calculating the inhomogeneous deformation in the shield tunnel of adjacent in-service metro directly caused by foundation pit excavation,an energy approach was proposed to overcome the deficiency of traditional method in which shield tunnel was regarded as equivalent homogeneous elastic foundation beam.The additional stress of tunnel due to foundation pit excavation was calculated by Mindlin fundamental solution.With coordinate transformation,the intersection angle between tunnel and the axis of foundation pit was considered.The lining ring of shield tunnel was regarded as a series of short elastic foundation beams connected by shear spring.The model was established for calculating tunnel deformation due to foundation pit excavation considering step between rings.The governing variational equations were developed by the principle of minimum potential energy to work out the vertical deformation,horizontal deformation and step between rings.The calculated results were compared with field test data and the results obtained from elastic foundation beam method,the results of the proposed method agreed better with field test data,and the proposed method was of higher computational efficiency.