酸处理页岩的损伤效应与力学特性  

Damage effects and mechanical properties of the acid-treated shales

作　　者：刘先珊[1,2] 周虎 张立君[3] 李满 乔士豪 潘玉华 侯泽林 郝梓宇 LIU Xian-sha;ZHOU Hu;ZHANG Li-jun;LI Man;QIAO Shi-hao;PAN Yu-hua;HOU Ze-lin;HAO Zi-yu(Key Laboratory of New Technology for Construction of Cities in Mountain Areas with the Ministry of Education,Chongqing University,Chongqing 400045,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China;Hubei Zhanghe Administration Bureau,Jingmen 448156,Hubei,China)

机构地区：[1]重庆大学山地城镇建设与新技术教育部重点实验室,重庆4000045 [2]重庆大学土木工程学院,重庆4000045 [3]湖北省漳河工程管理局,湖北荆门448156

出　　处：《兰州大学学报（自然科学版）》2022年第6期831-841,846,共12页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(52279094);广西重点研发计划项目(桂科AB20238036)。

摘　　要：以重庆市页岩气区块的露头页岩为研究对象,通过页岩的酸处理试验,分析酸处理页岩的相对质量损失、相对孔隙率增量及力学参数的变化规律,探究各参数对酸处理时间的依赖性,建立酸处理页岩化学损伤变量与各参数的关联,表明同一页岩的化学损伤变量越大其力学参数越小.对比不同层理倾角及不同酸化时间的页岩力学响应特征.结果表明,同一荷载的酸处理页岩峰值强度相对较低,酸处理时间越长,化学损伤越大,力学参数及峰值强度降低越多.基于胡克定律对比原页岩和酸处理页岩的裂纹演化过程,说明裂纹环向应变可以表征页岩的破裂过程,运用损伤力学研究页岩破裂过程中的损伤规律.建立页岩损伤与裂纹环向应变的表达式,揭示酸处理页岩的损伤渐裂机理.With an outcrop shale in the shale gas field in Chongqing as a case study,acid-treated experiments were done to obtain the variations in the relative mass,secondary porosity and mechanical parameters;the results showed that the above parameters were deeply dependent upon the immersion time,and there was a relationship between the chemical damage and above parameters,indicating that the chemical damage on the same shale was greater and the mechanical parameters smaller.The mechanical response of the shale with regards to a different dip angle and acid-treated time was compared and a conclusion drawn,i.e.the peal strength of the acid-treated shale under the same loading condition was lower,and especially the mechanical parameters and peak strength decreased much more with a greater chemical damage with regards to a longer acid-treated time.The mechanical theory was used to compare the crack evolution about the original shale and acid-treated shale,explaining that the crack circumference strain could represent the process of the shale failure,and the damage theory was also used to research into the damage variations for the shale failure.The expression for the shale damage and crack circumference was proposed to reveal the gradual-crack mechanism.

关 键 词：酸处理页岩 页岩气 化学损伤 力学响应 损伤渐裂 

分 类 号：TU45[建筑科学—岩土工程]