变化裂隙岩体的压缩破坏RFPA数值模拟  

RFPA Numerical Simulation of Compression Failure of Variable Cracked Rock Mass

作　　者：唐红梅[1] 王平[1] 王林峰[1] TANG Hongmei;WANG Ping;WANG Linfeng(Key Laboratory for Geological Disaster Reduction of Waterway Transportation in Mountain Areas,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学山区公路水运地质减灾重点实验室

出　　处：《重庆交通大学学报（自然科学版）》2020年第2期103-110,共8页Journal of Chongqing Jiaotong University(Natural Science)

基　　金：国家自然科学基金项目(51378521,51678097)

摘　　要：岩体的结构面特征对岩体的变形与破坏产生重要影响,探讨含裂隙岩体破坏过程中裂纹扩展、强度及能量特征具有重要意义。运用数值模拟软件RFPA,选用灰岩物理力学参数,采用单向压缩应力状态,分析了裂隙岩体的初始裂隙不同水平位置、倾角及长度对裂隙岩体破坏的影响,共14个工况。模拟结果表明:裂隙的水平位置对裂纹的上、下扩展角的影响不大,随着裂纹水平位置a的增大,上裂隙扩展线出现的时间越来越早,裂隙水平位置对其峰值强度影响较小;随裂隙倾角的增长,上、下扩展角迅速降低,试件峰值强度随之增加;随裂隙长度的增加,上、下扩展角迅速增长,峰值强度呈减小的趋势;裂隙的水平位置、倾角及长度对裂隙岩体残余强度影响很小。通过对14个工况的能量和声发射活动发现:当预制裂隙远离轴线时岩体破坏呈“双峰”型破坏;当预制裂隙为陡倾裂隙时岩体破坏呈“瘦高”型破坏;当预制裂隙为缓-中倾角裂隙时岩体破坏呈“矮胖”型破坏。研究结果对灰岩地区危岩的防治治理具有重要意义。The structural plane characteristics of rock mass have important influence on the deformation and failure of rock mass.It is of great significance to study the characteristics of crack expansion,strength and energy during the failure of cracked rock mass.Selecting the physical and mechanical parameters of limestone and adopting the state of one-way compression stress,the influence of different horizontal position,dip angle and length of the initial fracture on the cracked rock mass was analyzed by numerical simulation software RFPA in 14 working conditions.The simulation results show that the horizontal position of the crack has little effect on the upper and lower propagation angles of the crack;with the increase of crack horizontal position a,the time of upper crack growth line appears earlier and earlier,and the influence of crack horizontal position on its peak strength is less;with the increase of crack dip angle,the upper and lower propagation angles decrease rapidly,and the peak strength of specimen increases;with the increase of crack fracture length,the upper and lower propagation angles increase rapidly,and the peak strength tends to decrease.The above three factors have little influence on the residual strength of cracked rock mass.Through the energy and acoustic emission activities of 14 working conditions,it is found that:when the prefabricated fracture is far away from the axis,it is of“double-peak”type;when the fracture is steep,it is of“thin-high”type;when the fracture is gentle to medium dip,it is of“short-fat”type.The research results are of great significance to the prevention and control of dangerous rock in limestone area.

关 键 词：岩土工程 岩土力学 裂隙岩体 数值模拟 破坏 

分 类 号：TU459[建筑科学—岩土工程]