人工冻结红砂岩三轴压缩特征应力试验研究  

Experimental study on artificial frozen red sandstone characteristic stress under triaxial compression

作　　者：单仁亮[1] 宋永威 杨昊[1] 郭志明[1] 赵伟[1] 陈帆[1] SHAN Ren-liang;SONG Yong-wei;YANG Hao;GUO Zhi-ming;ZHAO Wei;CHEN Fan(School of Mechanics and Civil Engineering,China University of Mining and Technology,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)力学与建筑工程学院,北京100083

出　　处：《煤炭工程》2018年第9期101-106,共6页Coal Engineering

摘　　要：为研究不同温度、围压条件下西北人工冻结红砂岩特征应力的变化规律,采用冻三轴试验机对红砂岩进行不同温度(-15℃、-10℃、-5℃及10℃)、不同围压(4MPa、8MPa及12MPa)试验,并对应力应变曲线各特征应力阈值进行统计分析。研究发现:起裂应力随温度升高先增大后减小,扩容应力及峰值应力均随温度的增大而降低;起裂应力、扩容应力、峰值应力均随着围压的增大而增大,起裂应力、扩容应力与峰值强度比值均随着围压的增大而减小;起裂应力与峰值强度比值分布较广,最低为0.373,最大为0.721,扩容应力与峰值强度比值均集中在0.9附近;可释放弹性应变能占应变能的69.79%~98.51%,耗散能较小,峰值点后,可释放弹性应变能急剧释放,耗散能急剧增大,试样最终破坏。In order to study the law of the characteristic stress of northern artificial frozen red sandstone,the frozen triaxial compression test system was used in the test of frozen red sandstone under different temperatures（-15℃,-10℃,-5℃and 10℃） and confining pressures（ 4 MPa,8 MPa and 12 MPa） and the stress thresholds of stress-strain curves are statistically analyzed. The results show that： when the temperature increases,the crack initiation stress increases firstly and then decreases,while crack damage stress and peak stress decrease; when the confining pressure increases,the crack initiation stress,crack damage stress and peak stress increase. The ratio of crack initiation stress to peak stress and the ratio of crack damage stress to peak stress decrease with the increase of confining pressure. The ratio of crack initiation stress to peak stress is widely ranged from 0. 373 to 0. 721, and the ratio of crack damage stress to peak strength is concentrated around 0. 9. The elastic strain energy accounts for 69. 79% ~ 98. 51% of the strain energy,and the dissipation energy is small. After the peak point,the failure of the specimen leads to a sharp decrease of elastic strain energy and a sharp increase of dissipation energy.

关 键 词：冻结红砂岩 特征应力 应力阈值 应变能 

分 类 号：TU452[建筑科学—岩土工程]