摘要
通过受载煤岩工业CT扫描系统进行了不同围压下原煤的三轴压缩试验,探究不同围压下原煤的力学特性和破坏特征,并结合自身的CT扫描系统获得了原煤失稳破坏全过程CT扫描信息,分析了在不同围压下原煤的裂隙扩展演化规律。结果表明:(1)随着围压的增大,偏应力应变曲线整体向右偏移,峰值强度呈线性增长、而峰值应变和弹性模量均以二次函数的形式上升,且峰值强度的增长量最大;(2)基于CT扫描图像,煤样内部裂隙演化特征可以分为裂隙压密缓慢减少阶段、裂隙萌生稳定发育阶段、裂隙快速增加阶段、裂隙扩展贯通阶段4个阶段,且随着围压的增加,裂纹密度逐渐减小;(3)在三轴加载下,原煤的破坏形式以剪切破坏为主,破断角大小为20°~40°,且随着围压的增加,破断角呈二次函数增长。研究结果对井下巷道、采场支护设计、围岩稳定性判断和矿井灾害事故防治具有参考意义。
The triaxial compression tests of raw coal under different confining pressures were carried out by the industrial CT scanning system of coal and rock under load to investigate the mechanical properties and damage characteristics of raw coal under different confining pressures,the CT scanning information of the whole process of destabilization and damage of raw coal was obtained by combining with its own CT scanning system,and the evolution law of crack propagation of raw coal under different confining pressures was analyzed.The results show that:(1)With the increase of confining pressure,the overall bias stress-strain curve shifts to the right,the peak strength increases linearly,while the peak strain and elastic modulus both increase as a quadratic function,and the peak strength increases by the largest amount;(2)Based on the CT scan images,the fracture evolution characteristics inside the coal sample can be divided into four stages:fracture pressure density slowly decreasing stage,fracture sprouting stable development stage,fracture rapid increase stage,fracture expansion through stage,and with the increase of confining pressure,the fracture density gradually decreases;(3)Under triaxial loading,the damage of raw coal is mainly in the form of shear damage,with the size of the breaking angle ranging from 20°to 40°,and with the increase of confining pressure,the breaking angle increases as a quadratic function.The research results have certain reference significance for underground roadway,stope support design,surrounding rock stability judgment and mine disaster and accident prevention.
作者
王磊
张宇
陈礼鹏
李少波
朱传奇
Wang Lei;Zhang Yu;Chen Lipeng;Li Shaobo;Zhu Chuanqi(State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mine,Anhui University of Science and Technology,Huainan,Anhui 232001,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2024年第5期1503-1514,共12页
Chinese Journal of Underground Space and Engineering
基金
安徽高校协同创新资助项目(GXXT-2020-055)
安徽省科技重大专项项目(202203a07020010)。
关键词
围压
原煤
力学参数
CT扫描
裂隙演化
confining pressure
raw coal
mechanical parameters
CT Scan
fracture evolution
