不同围压条件下砂岩动态剪切特性数值模拟分析  

Numerical simulation on dynamic shear characteristics of sandstone under different confining pressures

作　　者：朱看远 赵格立 徐颖[1,2] 江丽媛 ZHU Kan-yuan;ZHAO Ge-li;XU Ying;JIANG Li-yuan(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072,China;School of Civil Engineering and Architecture,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300072 [2]天津大学建筑工程学院,天津300350

出　　处：《工程爆破》2022年第4期25-33,43,共10页Engineering Blasting

基　　金：国家自然科学基金资助项目(52079091);天津市自然科学基金重点资助项目(19JCZDJC40400)。

摘　　要：岩石的剪切破坏是工程爆破中常见的破坏模式,因此对岩石的动态剪切强度的测定具有重要意义。而深部岩石的破坏则需考虑围压条件,但目前普遍是在较低围压条件下(<20 MPa)研究岩石的动态剪切特性。为研究更高围压条件下(>20 MPa)岩石的动态剪特性,基于ABAQUS有限元软件,采用Drucker-Prager(D-P)塑性模型,结合率相关性,对低围压条件下分离式霍普金森压杆动态冲剪实验进行模拟,并从力平衡、加载率、岩样的破碎特征和剪切强度方面与实验结果进行了对比分析,研究表明:基于ABAQUS的数值模拟方法能够重现冲剪实验现象;D-P模型能较好的反映岩石的剪切强度特性和破裂特征,与实验结果相符。以上结果验证了模拟方法以及模型参数的合理性和适用性。在此基础上,对更高围压下的砂岩的冲剪特性进行了预测性的模拟研究。结果显示:更高围压条件下,随着围压的增大,岩样的破裂裂纹减少;加载率相差不大的情况下,岩样的剪切强度随围压的增大而增大;围压一定的情况下,岩样的动态剪切强度随着加载率的增大而增大。Shear failure of rock is a common failure mode in engineering blasting,so it is of great significance to determine the dynamic shear strength of rock.The failure of deep rock needs to consider the confining pressure condition,but it is common to study the dynamic shear properties of rocks under low confining pressure conditions(<20 MPa).In order to study the dynamic shear characteristics of rock under higher confining pressure(>20 MPa),based on ABAQUS finite element software,Drucker-Prager(D-P)plastic model and rate dependence were adopted to simulate the dynamic shear experiment under low confining pressure.Compared with dynamic force balance,loading rate,fracture characteristics and shear strength,the results show that the numerical simulation based on ABAQUS can reproduce the experimental phenomenon;D-P model can better simulate the strength characteristics and fracture characteristics of rock,which is consistent with the experimental results.The above results verify the rationality and applicability of the numerical simulation and model parameters.On this basis,the predictive simulation study of the punch shear characteristics of sandstone under higher confining pressure is carried out.The results show that under the condition of higher confining pressure,the cracks of rock sample decrease with the increase of confining pressure.The shear strength increases with the confining pressure when the loading rate is consist.Under a certain confining pressure,the dynamic shear strength of rock increases with the increase of loading rate.

关 键 词：动态剪切强度 DRUCKER-PRAGER模型 分离式霍普金森压杆(SHPB) 围压 加载率 ABAQUS 

分 类 号：TD235[矿业工程—矿井建设]