各向异性岩体中不同接触衬砌隧洞的解析分析

Analytical Solution of Tunnel under Different Contact Conditions of Lining in Anisotropic Rock Mass

通过复变函数方法建立分析了非圆形水工衬砌隧洞,在衬砌与围岩处于完全和光滑接触条件下的解析解,考虑了衬砌的支护滞后效应和洞内水压作用。研究了正交各向异性岩体中的马蹄形衬砌隧洞,在不同接触条件和洞内压力工况下,接触边界和衬砌自由边界上的应力和位移解。接触条件对衬砌接触边界的切向应力分布影响最显著,完全接触条件下两底脚的切向压应力最大,光滑接触条件下最小。岩体各向异性和倾斜结构面对衬砌中力学分量的非对称性影响在完全接触条件下明显。完全接触条件可高效发挥衬砌的支撑作用,光滑接触条件使岩体的自承能力充分体现。衬砌在两种接触条件下均承担了大部分由水压引起的张拉效应。

Under the pure-bond and the full-slip contact conditions, analytical solutions for hydraulic lined tunnel of non-circular shape are solved by complex variable method, in which the support delay effect of lining and internal water pressure are considered. The stress and displacement solutions on the contact boundaries and lining free boundary of a horseshoe shaped tunnel in orthotropic rock mass are studied under different contact conditions and internal pressures. Contact condition has a significant influence on the tangential stress on lining contact boundary, where the compressive stress on tunnel feet is largest under pure-bond contact condition but smallest under full-slip contact condition. The influence on the asymmetry of mechanical components in lining caused by rock anisotropy and inclined structure plane is more obvious under pure-bond contact condition. Pure-bond contact condition can effectively play the supporting role of lining. Full-slip contact condition reflects the self-bearing capacity of surrounding rock mass. Lining bears the most tension effect caused by water pressure under both two contact conditions.