既有路基下浅埋隧道开挖引起地层的位移及应力解析解

在既有公路下进行浅埋隧道开挖会引起地层产生位移，导致地表沉降。为了保证施工安全，快速精确地计算地层位移及应力，有效地控制地表沉降，对浅埋隧道的设计与施工均十分重要。在镜像法原理的基础上，引入等效模量当层法，推导出了在有上覆不同材料下浅埋圆形隧道开挖引起地层位移、应力及地表沉降的解析分布规律。计算结果表明，既有路基下开挖隧道引起地层产生的位移和应力解析解能够很好地体现上层高弹性模量路基对沉降及应力的扩散作用，可以求得隧道开挖后洞周地层包括上覆路基及下卧层中任意位置处的位移、应力以及地表沉降，为在双层地基材料中开挖浅埋隧道引起地层位移及地表沉降的计算提供了一种新的解析方法。

An analytical solution for displacement and stress caused by shallow buried tunnel excavation under existing highway foundation

Excavation under existing highway foundation will cause ground displacement and ground settlement. In order to control the ground settlement during excavating, it is important to solve out the ground displacement and stress quickly and accurately for design and construction. Based on image method and injected with equivalent layer method, the analytical solution of ground displacement and stress caused by shallow buried circular tunnel excavation under existing highway foundation is deduced. The result indicates that the ground displacement and stress law gained through this new solution can reflect the special transfer effect of settlement and stress via the upper harder highway foundation. The displacement and stress at any position in the highway foundation and the substratum and ground settlement can be gained through this solution, so as to provide a new analytical method for the calculation of ground displacement and ground settlement caused by circular tunnel excavation in double-layer ground material.