基于离散元法的岩石时效性流变模型研究  

Time-dependent rheological model of rock based on discrete element method

作　　者：吴博文 常聚才[1] 柏建彪[2] 王襄禹[2] 王拓[1] 史文豹[1] WU Bowen;CHANG Jucai;BAI Jianbiao;WANG Xiangyu;WANG Tuo;SHI Wenbao(School of Mining Engineering,Anhui University of Science&Technology,Huainan,Anhui 232001,China;School of Mines,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China)

机构地区：[1]安徽理工大学矿业工程学院,安徽淮南232001 [2]中国矿业大学矿业工程学院,江苏徐州221116

出　　处：《采矿与安全工程学报》2023年第6期1273-1280,共8页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金项目(52174105,52204079);安徽省重点研发计划项目(202004a07020045);安徽理工大学引进人才基金项目(2023yjrc28)。

摘　　要：为建立一种基于离散元方法的岩石时效变形模型,采用MTS Criterion64.206试验系统和PCI-2声发射系统开展砂质泥岩单轴流变试验,分析砂质泥岩时效变形和声发射特征,基于等效变换的摩尔库伦准则、岩石长短期强度关系和裂纹静态疲劳失效机制,在UDEC中建立岩石时效变形模型。研究结果表明:岩石流变期间内部裂纹不断孕育扩展,加速流变破坏前,岩石发出大量声发射信号;岩石时效强度主要受内聚力控制,建立内聚力与时间的函数关系可实现块体强度衰减;以接触面两侧块体内屈服变形体数量比例关系作为转换系数,可将块体强度衰减机制运用于接触面;屈服变形体个数与岩石流变失稳密切相关,屈服变形体的增加导致接触面强度下降;模拟与试验的应变及损伤特征匹配度较好,验证了模型的合理性。以淮北某矿轨道上山为工程背景,运用开发的模型进行数值模拟,模型较好地反映了巷道围岩破坏特征,揭示了巷道围岩阶段变形特征及巷道大变形机制。In order to establish a rock time-dependent deformation model based on the discrete element method,uniaxial rheological tests of sandy mudstone is carried out with the MTS Criterion 64.206 test system and the PCI-2 acoustic emission system.The time-dependent deformation and acoustic emission characteristics of sandy mudstone are analyzed.Based on the Mohr-Coulomb criterion of equivalent transformation,the relationship between the long-term and short-term strength of rock and the static fa-tigue failure mechanism of cracks,and a rock time-dependent deformation model are established in UDEC.The research results show that the internal cracks propagate continuously during the rheological process,and a large number of acoustic emission signals are released before the accelerated rheological failure.The aging strength of rock is primarily controlled by cohesion,and it is possible to attenuate block strength by establishing a functional relationship between cohesion and time.Taking the propor-tional relationship between the number of yield deformation bodies in the blocks on both sides of the con-tact surface as the conversion coefficient,the block strength attenuation mechanism can be applied to the contact surface.The number of yield deformation bodies is closely related to the rheological instability of rock.The contact strength decreases when yield deformation bodies grow.The rationality of model is confirmed by a good match between the strain and damage characteristics of the simulation and the test.Taking the rail rise of a mine in Huaibei as the engineering background,the developed model is used to carry out numerical simulation,which reflects the failure characteristics of roadway surrounding rock much better.The stage deformation characteristics of roadway surrounding rock and the mechanism of large deformation of roadway are revealed.

关 键 词：离散元 时效变形 流变模型 强度衰减 参数校正 

分 类 号：TD32[矿业工程—矿井建设]