摘要
通过轮廓法追踪岩石裂纹扩展轨迹，将其嵌入ABAQUS扩展有限元（EFE）平台，对单轴压力下裂隙试件受压过程进行了模拟验证，裂纹起裂扩展效果良好。以此为平台，将推导得到的弧形裂纹应力强度因子嵌入其中，以最大周向拉应力准则为开裂准则，认为当其大于岩体断裂韧度时，硐室围岩体内初始裂纹将开始扩展。在此基础上，以发现分区破裂现象的圆形隧道模型试验为背景开展了分区破裂的数值模拟试验。模拟结果发现，深部巷道围岩出现了3～4层破裂分区，证实深部巷道围岩存在分区破裂现象。将数值模拟结果与模型试验完成后模型围岩破坏状态对比，发现二者破裂区分布特征基本一致。数值模拟结果表明，EFEM方法在处理复杂岩体裂纹问题方面的有效性。
The contour method of tracking the trajectory of rock crack propagation was embedded into extended finite elements （EFE） platform of ABAQUS to simulate the process of initial crack extension under uniaxial pressure. The result testifies the effective of the simulation method. Then, the arc-circular fracture stress strength factor was embedded into the EFE platform. Using the maximum circumferential tensile stress criterion as cracking criterion, when the stress is greater than that rock fracture toughness, the initial crack within surrounding rock begins to extend. Based on this, a numerical simulation of the simplified round tunnel is carried out with the model test which the zonal disintegration phenomenon is observed. During the simulation process, the subdomain precise integration is adopted to improve the precision. The simulation results show that there appears 3 to 4 layer zonal disintegrations surrounding the deep tunnel. The numerical simulation indicates that there exists zonal disintegration phenomenon in deep surrounding rock mass. Comparing the numerical simulation with the ruin pattern of tunnel model after the model test, it is found that the distribution character is in coincidence with each other. The numerical simulation results show that the EFE method is effective in dealing with the problems of complex fracture in rock mass.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2013年第11期3291-3298,共8页
Rock and Soil Mechanics
基金
国家自然科学基金项目(No.51209074
No.41172268)
中国博士后基金特别资助项目(No.2013T60494)
中国博士后科学基金资助项目(No.2012M511189)
岩土力学与工程国家重点实验室开放基金(No.Z012008)
中央高校基本科研业务费专项资金(No.2012B02714)资助
关键词
分区破裂
扩展有限元法
应力强度因子
子域积分
zonal disintegration
extended finite element method（EFEM）
stress strength factor
subdomain precise integration
