围压对砂岩破裂过程中的应力演化影响分析  

Analysis of stress evolution during sandstone failure process affected by confining pressure

作　　者：王建强 尹小涛[2] 

机构地区：[1]云南地质工程第二勘察院,昆明650051 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071

出　　处：《岩土力学》2011年第12期3833-3838,共6页Rock and Soil Mechanics

基　　金：国家科技支撑计划重点课题(No.2006BAK30B02)

摘　　要：如何准确无损地获取岩土材料的内部应力演化信息,对于研究围压对材料破坏行为的物理机制有很大帮助。在颗粒流数值平台下,设计了0.0、0.5、1.0 MPa砂岩三轴压缩试验,根据获取的试件破坏形态、宏观应力-应变曲线,左右侧、中间竖向设置的上中下部共计9个测量点测得的x、y、xy方向应力监测结果,分析了材料破坏的力学机制和围压对材料破坏的影响机制,结果表明:上左下右剪切带发展优于上右下左,随着围压的增强,对这种优势有抑制作用,即剪切带更倾向于等速发展,这从微裂纹揭示的破坏形态也可以得到间接印证,围压使得变形更为明显。How to accurately and nondestructively obtain inner stress evolutional data of rock and soil material is helpful to study physical mechanism of material failure affected by confining pressures.The triaxial compression tests of sandstone under confining pressures of 0.0,0.5 and 1.0 MPa are designed based on the particle flow code（PFC） software.According to failure shape,macro-stress-strain curve and stress data in x,y,xy directions at nine monitoring points on left and right sides or middle of specimen,mechanical mechanism and influence by confining pressure of material failure process are analysed.It is found that the shear band located from upper left corner to lower right one develops enough than shear band situated from upper right corner to lower left corner,which is limited with increase of confining pressure;that is to say shear band tends to expand with same velocity because of confining pressure.It can also be indirectly proved by failure shape explained by microcracks;and that confining pressure makes strain more obvious.

关 键 词：颗粒流 砂岩 围压 破坏 应力 

分 类 号：TU452[建筑科学—岩土工程]