深部巷道围岩分区破裂化数值模拟  

Numerical simulation on disintegration of surrounding rock mass in deep mine roadways

作　　者：王红英[1] 张强[1] 张玉军[1] 蒋开法[2] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]山东科技大学土木建筑学院,山东青岛266510

出　　处：《煤炭学报》2010年第4期535-540,共6页Journal of China Coal Society

基　　金：国家自然科学基金面上资助项目(50774082;50804046);国家重点基础研究发展计划(973)资助项目(2010CB732101);岩土力学与工程国家重点实验室前沿探索性资助项目(SKLQ008)

摘　　要：对应变软化模型岩体的变形机理进行分析,确定了巷道围岩产生分区破裂的前提条件为岩体变形进入峰后塑性及残余破坏阶段。对地下硐室围岩应力变形状态进行FLAC数值模拟,并基于破坏接近度指标对围岩完整状态进行描述。结果表明:分区破裂化与岩体峰后特性密切相关,是应变软化模型特有的属性,理想弹塑性模型并不能产生分区破裂化;计算结果对网格精度具有依赖性,当近巷网格大小为巷道半径的1/60时,巷道围岩出现螺旋带破裂区域,产生分区破裂,而在粗糙网格下则为传统弹塑性环状对称变形;分区破裂化区域受平面内侧压力系数影响显著,分区破坏主要集中在硐室围岩应力较大的方位;分区破裂化是巷道开挖过程中二次应力场在时间和空间重分布的结果。Through the rock mass deformation mechanism analysis under strain-softening model,the precondition of zonal disintegration was determined,namely,the rock mass deformation reaches the post-peak softening and residual fracture stage.The excavating roadway deformation was analyzed through FLAC numerical simulation whose intact state was described by failure approach index（FAI）,the results show that zonal disintegration is closely related to the post-failure character,and it is peculiar to strain-softening model rather than ideal elastic-plastic model;the calculation results depends on mesh precision.When the cell size near the roadway is 1/60 of the roadway radius,surrounding rocks appears spiral zonal cracked region,which leads to zonal disintegration.Whereas traditional annular deformation occurs under coarse mesh precision;zonal disintegration region is highly influenced by the lateral pressure coefficient in plane,the region mainly concentrate on the roadway wall where stress is larger.Zonal disintegration is the interaction result of the secondary stress field in time and space during the roadway excavation.

关 键 词：深部岩体 分区破裂 软化模型 网格精度 应力释放 破坏接近度 

分 类 号：TD313[矿业工程—矿井建设]