基于PFC3D模拟的卸荷岩柱破坏规律研究  

Research on Failure Law of Unloading Rock Column Based on PFC3D Simulation

作　　者：王尚想 李宁[1] WANG Shangxiang;LI Ning(School of Mining Engineering,Anhui University of Science and Technology)

机构地区：[1]安徽理工大学矿业工程学院,安徽省淮南市232001

出　　处：《现代矿业》2025年第2期52-56,61,共6页Modern Mining

基　　金：中国博士后科学基金面上项目(编号:2020M681975)。

摘　　要：为分析深部开采中岩柱在不同方向主应力卸载下的破坏及冲击规律,使用PFC3D软件设计六面加载—双面卸载的应力路径,进行岩石试样三轴压缩试验模拟。通过卸载中间或最小主应力,模拟卸荷岩柱实际应力路径变化过程,进而探究其在不同方向卸荷下的宏观应力应变特征及破坏规律,并分析内部裂纹的细观扩展形态。结果表明,在宏观层面上,随着非临空面应力的增加,试样的峰值强度不断提高,峰值点轴向应变不断增加,位移主体向着临空面扩展和轴向方向收缩;在细观层面上,试样内部先产生剪切裂纹,在到达峰值强度的90%时产生张拉裂纹,剪破坏数占总黏结破坏数的比例随中间和最小主应力的增加而增大,而黏结破坏总数有减少趋势。研究结果能为深部开采时巷道掘进过程中的煤岩柱冲击灾害防治提供一定参考。In order to analyze the failure and impact law of rock column under different directions of principal stress unloading in deep mining,PFC3D software is used to design the stress path of six-sides load-ing and two-sides unloading,and the triaxial compression test of rock samples is simulated.By unloading the intermediate or minimum principal stress,the actual stress path change process of the unloaded rock col-umn is simulated,and then the macro-stress-strain characteristics and failure rules under different unload-ing directions are studied,and the microscopic expansion patterns of internal cracks are analyzed.The re-sults show that,at the macro level,with the increase of stress on the non-free plane,the peak strength of the sample increases continuously,the axial strain at the peak point increases continuously,and the dis-placement body expands towards the free plane and shrinks in the axial direction.At the meso-level,shear cracks occur first inside the specimen,and then tensile cracks occur when 90%of the peak strength is reached.The proportion of shear failure to the total bonding failure increases with the increase of the interme-diate and minimum principal stresses,while the total bonding failure decreases.The research results can provide some reference for the prevention and control of coal rock pillar impact disaster in the process of deep mining.

关 键 词：PFC3D 颗粒流 双面临空 剪切破坏 

分 类 号：TD315[矿业工程—矿井建设]