考虑损伤的圆形巷道围岩弹塑性分析

Elasto-plastic analysis of circular roadway surrounding rocks under consider ation of rock damage

如何判断巷道开挖后,围岩弹塑性变形及围岩的力学行为一直是人们研究的重点问题。考虑岩石材料的损伤特性,建立了巷道围岩弹塑性损伤力学模型,对侧压力系数为1时圆形巷道围岩的弹塑性应力场及范围进行分析。结合具体算例,得出在相同塑性范围内,随着λ/E比值的增大,所需要的支护阻力也随之增大;当原岩应力一定时,随着λ/E比值的增大,巷道围岩的塑性区范围也随之增加。研究表明,考虑损伤作用使得分析结果更加接近于实际,从而为巷道围岩稳定性分析和合理选择支护形式及强度提供理论依据。

How to judge the elastic-plastic deformation as well as the mechanical behavior of surrounding rock after the tunnel excavated , has been a focus of research .This paper considers the damage characteristics of rock materi-al, established the elastic-plastic damage model of roadway surrounding rocks , analyzed the elastic-plastic stress field and the scope of circular roadway surrounding rocks when the lateral pressure coefficient equals 1.0.Combi-ning with the concrete examples , reached a conclusion that within the same scope of plastic range , the λ/E ratio increases,the supporting resistance increases;when the primary rock’s stress fixed, with the raise of λ/E ratio,the plastic zone of roadway surrounding rocks increases as well .Research indicates that , taking the damage effect into account , the analysis results could be much more close to the reality ,so that it provides the theory basis to analyzing the stability of roadway surrounding rocks and the reasonable selection of supporting form and intensity .