裂隙岩体中径向位移的双场耦合蠕变分析

Double-Field Coupling Creep of Radial Deformation in Fracture Rock

在富含裂隙的岩体中,隧道开挖引起应力场和渗透场的变化而产生卸荷变形是非常复杂的力学过程。运用粘弹性断裂、蠕变理论,建立在裂隙岩体中隧道开挖的双场耦合蠕变模型,结合Laplace转换推导出围岩的径向位移函数表达式,说明应力卸荷、渗流力的作用以及节理裂隙分布对径向位移的影响。模型计算结果表明,径向最大位移变化量并不在主应力最大方向,也不在隧道顶端,而是受地应力分布、渗透水压和节理分布等综合作用有所偏移。

Due to the change of stress field and the seepage field caused by tunnel excavation,unloading deformation is a complicated mechanical process in rich fracture rock. By viscidity elastic fracture and creeping theory, doublefield coupling creep model of tunnel excavation in rich fracture rock is established, and Laplace transformation is applied to deduce the expression of radial deformation function, so as to illuminate the influence of radial deformation from stress unloading distribution, seepage force and crevasse distribution. The model shows the radial biggest displacement mutative quantities are not in the orientation of the principal nor in the tunnel peak, but have bias displacement under the comprehensive function of geo-stress distribution,seepage pressure and joint distribution.