冻融循环后砂岩抗冲击力学特性及数值模拟  

Sandstone Impact Mechanical Properties and Numerical Simulation after Freeze-Thaw Cycles

作　　者：李宇白 翟越[1] 李艳[1] 孟凡东 张韵生 Li Yubai;Zhai Yue;Li Yan;Meng Fandong;Zhang Yunsheng(School of Geology Engineering and Geomatics,Chang'an University,Xi'an 710064,P.R.China)

机构地区：[1]长安大学地质工程与测绘学院,西安710064

出　　处：《地下空间与工程学报》2022年第5期1580-1587,共8页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金委员会重大项目(41941019);国家自然科学基金(41772277)。

摘　　要：长期冻融循环作用对砂岩力学性能的影响是岩石力学和地下空间工程研究的前沿问题。通过对冻融循环作用后的砂岩进行CT扫描和霍普金森杆(SHPB)冲击压缩,以宏-细(微)观结合的试验手段和数值模拟技术解释冻融砂岩从初损状态到裂隙形成这一演变过程及力学响应。结果表明:冻融循环作用使砂岩内天然孔隙不断扩展,随着冻融次数的增多,试件孔隙、裂隙逐渐增大,冲击压缩后导致峰值强度降低;由破碎模拟可知,冲击后试件轴向压缩并且径向膨胀,达到极限后致使破坏,应力在中心处最大并向边缘环向递减。The influences of long-term freeze-thaw cycles on the mechanical properties of sandstone is a frontier issue in rock mechanics and underground engineering research.Through CT scanning and split Hopkinson pressure bar(SHPB)impact compression of sandstone after freeze-thaw cycles,based on the combined macro-microscopic test method and numerical simulation technology,the evolution process and mechanical response of freeze-thaw sandstone from initial damage state to fracture formation are analyzed.The results show that:The freeze-thaw cycles lead to the natural pores in the sandstone expanding continuously.As the number of freeze-thaw cycles increases,the pores and cracks of the specimen gradually increase,and the peak strength decreases after impact compression.It can be seen from the crushing simulation that after the impact,the specimen is compressed axially and expanded radially.When the limit is reached,the specimen will be broken.The stress is the largest at the center and decreases toward the edge.

关 键 词：冻融循环 CT扫描 冲击压缩 砂岩 数值模拟 

分 类 号：O341[理学—固体力学]