岩层产状对层状岩体地下厂房围岩松弛变形特征影响分析

针对层状岩体地下厂房围岩变形稳定问题，本文基于三维块体离散元软件（3DEC），采用数值模拟，研究岩层产状对层状岩体地下厂房围岩松弛变形特征的影响规律。研究结果表明，当岩层倾角小于30°时，厂房开挖后围岩最大变形发生在顶拱和底板部位，当岩层倾角大于60°时，最大变形发生在边墙部位；在相同条件下，随着岩层倾角的增加，厂房开挖后围岩的最大变形量和松弛区的深度表现出了先增大后减小的趋势，且当岩层倾角到达60°~70°时，其达到了峰值；随着厂房纵轴线与岩层走向的夹角的增大，围岩的最大变形量和松弛区的深度表现为逐渐减小的趋势，且当厂房纵轴线与岩层走向的夹角超过一定角度后，其基本上无明显的减小趋势。对于陡倾角层状岩体，地下厂房设计时，建议洞室纵轴线与岩层走向的夹角不宜小于60°。

Analysis of the influence of bedding attitude on the relaxation deformation characteristics of surrounding rock of underground powerhouse within layered rock mass

In order to study the stability of underground powerhouse with layered rock mass,numerical simulation was carried out based on the three-dimensional Distinct Element Code (3DEC). The influence of bedding attitude on the relaxation deformation characteristics of surrounding rock of underground powerhouse with layered rock mass was studied and the results have shown that when the bedding dip angle is less than 30°,the maximum deformation of surrounding rock occurs at the arch crown and bottom plate. However, when the dip angle is greater than 60°, the maximum deformation occurs at the side wall. Under the same conditions,with the increase of dip angle,the maximum deformation of the surrounding rock and the depth of the relaxation deformation zone (RDZ) increase first and then decrease,and reach the peak when dip angle reaches 60°~70°. With the increase of angle between the bedding strike and the longitudinal axis of the cavern, the maximum deformation and depth of RDZ decrease gradually. Moreover, such variation becomes stable when the angel is greater than a threshold angle. For the steeply inclined layered rock mass, when designing the underground powerhouse, it is suggested that the angle between the bedding strike and the longitudinal axis of the cavern should not be less than 60°.