下穿施工影响下既有隧道和地层的位移解析解

The Displacement Solution of Existing Tunnel and Ground by Traversing Construction

在既有隧道下进行浅埋隧道开挖会引起地层产生位移,继而导致既有隧道变形。由于既有隧道与地层刚度差别巨大,常规的解析法无法计算存在不同刚度的地层位移场。基于镜像法,采用当层法对既有隧道刚度进行等效,建立综合考虑新建隧道-岩土体-既有隧道三者相互作用的计算模型。以北京地铁10号线国贸站-双井站区间下穿既有1号线区间工程为例,采用该计算方法,研究新建隧道下穿施工对地层及既有隧道的影响。研究表明,计算结果与实测变形吻合较好,解析解能很好的解释既有隧道对地层变形的阻隔和扩散作用。研究成果为下穿施工引起的既有隧道及地层沉降计算提供了一种新的解析方法。

Tunnel excavation will cause the displacement of ground,which will lead to the displacement of the existing tunnel. Because of the great difference between the tunnel 's rigidness and the ground 's rigidness,the conventional analytical method cannot calculate the existence of different stiffness of the stratum displacement field.The stiffness of the existing tunnel is equivalent by the mirror method. A computing model which includes the new tunnel and rock mass and the existing tunnel is build. Taking Beijing metro line 10 crossing metro line 1 as an example,with this method,the influence of the existing and ground is studied. The results show that the calculated results are in good agreement with the experimental results,and the analytical solution can well explain the barrier and diffusion of the existing tunnel. The research results provide a new analytical method for the calculation of the existing tunnel and stratum settlement caused by the construction of the tunnel.