基于岩石非线性统一强度准则的非均匀应力场中圆形巷道围岩塑性区分析  

Plastic zone analysis of the surrounding rock mass in circular tunnel under non-uniform stress field

作　　者：张小波[1] 赵光明[1,2] 孟祥瑞[1] 

机构地区：[1]安徽理工大学能源与安全学院,安徽淮南232001 [2]重庆大学西南资源开发及环境灾害控制工程教育部重点实验室,重庆400044

出　　处：《安全与环境学报》2013年第3期202-206,共5页Journal of Safety and Environment

基　　金：国家自然科学基金项目(51174005);教育部科学技术研究重点项目(210096);霍英东青年教师基金基础性研究课题(121050)

摘　　要：为评价巷道围岩的安全稳定性和进行支护定量设计,分析非均匀应力场中巷道围岩的塑性区形态。考虑中间主应力、岩石性质和岩体结构特点对岩体变形破坏的影响,应用岩石非线性统一强度准则和弹塑性力学方法,推导出非均匀应力场中的圆形巷道围岩的塑性区边界线方程,研究了侧压系数、Hoek-Brown参数和中间主应力对塑性区形态的影响。结果表明,侧压系数对塑性区分布有很大影响,侧压系数不同,巷道顶底板和两帮的塑性区分布形态不同。岩体质量越好,Hoek-Brown参数越大,塑性区范围越小,反之,塑性区范围越大。考虑中间主应力能够发挥岩体的强度潜能,计算出的塑性区也随之变小。The present paper aims to introduce a theoretical study on the method to pre-estimate the plastic zone boundary with a safety analysis of the tunnel surrounding rock. In order to make an assessment of the surrounding rock stability and conduct a quantitative and qualitative design of the support,we have made an analysis of the size and shape of surrounding rock plastic zone. For this purpose, this paper analyzed the effect of the intermediate principal stress,the rock properties and structural characteristic effects of rock mass on its deformation and failure,while applying the nonlinear unified strength criteria and elasto-plastic mechanics for deducing a boundary equation of plastic zone under non-uniform stress field. And, next, we have studied the effect of lateral pressure coefficient,the Hoek-Brown parameters and the intermediate principal stress on the size and shape of the plastic zone with a few samples for analysis. The study results show that： when the lateral pressure coefficient is less than 1,the plastic zone on the two sides tends to be larger than that of the roof and floor. And, conversely,when the coefficient is greaterthan 1,the plastic zone in the roof and floor would be larger than that of the two sides. What is more, when the coefficient is equal to 1,the distribution of plastic zone would be a uniform one,which looks like a thick cyclic structure. On the other hand, if the Hoek-Brown parameters are larger with the better rockmass quality,the resistance to deformation or failure would be stronger,and, in turn, the size of the plastic zone would be smaller. On the contrary,if the rock mass is poorer in quality,the size of plastic zone should be made greater. Besides, the intermediate principal stress has also effect on the distribution of plastic zone,the rock mass strength should be made greaterwhile considering the intermediate principal stress,so as to meet the actual stress state of engineering rockmass. In this case,the size of the calculation results of the plastic zone should be made

关 键 词：采矿工程 非线性统一强度准则 侧压系数 岩体质量 中间主应力 塑性区边界 

分 类 号：TD322[矿业工程—矿井建设]