爆破载荷下岩石的拉压损伤模型  

Tension-compression damage model of rock under blasting load

作　　者：王卫华[1] 张恒根 李夕兵[1] WANG Weihua;ZHANG Henggen;LI Xibing(School of Resources and Safety Engineering,Central South University,Changsha 410083,China;College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中南大学资源与安全工程学院,湖南长沙410083 [2]中国海洋大学环境科学与工程学院,山东青岛266100

出　　处：《中南大学学报（自然科学版）》2021年第11期3918-3929,共12页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(41372278)。

摘　　要：根据岩石材料动态受拉表现为弹脆性、动态受压表现为弹塑性的特点,应用应变余能等效假说分别建立以裂纹密度表征拉伸损伤变量的动态拉损伤模型和以等效塑性应变表征压缩损伤变量的动态压损伤模型。在所建立的拉压损伤模型中考虑初始损伤的影响,并给出用于评价围岩是否受爆破影响的损伤阀值的计算公式。将所建立的拉压损伤模型和其他2种爆破损伤模型引入LS-DYNA中进行数值模拟,并将模拟结果与现场实测结果进行对比。研究结果表明:损伤主要沿炮孔径向扩展;与装药段平行的围岩中损伤半径的变化不大且主要为拉伸损伤;与堵塞段平行的围岩越接近地表,损伤半径越大,且在地表处有最大值;孔底部损伤主要为压缩损伤且损伤区域较小;采用拉压损伤模型所得的模拟结果与实测结果较吻合,表明所建立的抗压损伤模型具有工程实用性。According to the characteristics of elastic brittleness of rock material with dynamic tension and elasticplasticity under dynamic compression, a dynamic tensile damage model and a dynamic compressive damage model were established based on the equivalent hypothesis of residual strain energy. The former was modified based on the LIU model with crack density to characterize tensile damage variables, and the latter was based on the MOGI-COULOMB yield criterion with equivalent plastic strain to characterize compressive damage variables.In the established tension-compression damage model, the influence of initial damage was considered, and the calculation formula of damage threshold for evaluating whether surrounding rock affected by blasing was given.The tension-compression damage model and the other two blasting damage models were introduced into LS-DYNA for numerical simulation, and the simulation results were compared with the field test results. The results show that the damage mainly extends along the radial direction of the hole, and the damage radius in the surrounding rock parallelled to the charge section has little change and has mainly tensile damage. In the surrounding rock parallelled to the blockage section, the closer to the ground surface, the larger damage radius is and the maximum damage area is at the surface. At the bottom of the hole, there is mainly compression damage and the damage area is small. The simulation results of the tension-compression damage model are in good agreement with the measured results, and so the proposed model has engineering practicability.

关 键 词：岩石 爆破载荷 拉压损伤模型 初始损伤 爆破数值模拟 

分 类 号：TU45[建筑科学—岩土工程] TD235[建筑科学—土工工程]