(1. State Key Laboratory of Coal Mine Disaster Dynamics and Control，Chongqing University，Chongqing 400044，China；
2. State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam，Chongqing University，Chongqing 400044，China)
Abstract：The fine sandstone from the Xujiahe group of Three Gorges reservoir area is selected as object. The effect of various acid solutions with different pH values on sandstone under shearing load is investigated by using the independent development of meso-shear test equipment for coal rock. Simultaneously，temporal and spatial evolution law of microcrack of sandstone sample under the shear loading is researched by image processing technology. The relationship between the crack initiation and the degree of sandstone erosion was investigated. The results show that there is obvious correlation between the shear stress and crack evolution of sandstone at different time points，and process from surface crack?s initiation to the unstable failure of the samples was completed in a relatively short time. In the process of rupture failure of sandstone，it almost produced intergranular fracture in the mineral grain boundaries and cements，and transgranular fracture only produced in highly concentrated region of stress. Furthermore，as the increase of acidic strength of solution and time of erosion，the erosion degree and the deformation of sandstone increased，while the shear strength reduced and the width of crack corresponding increased，crack situation was more complex. Therefore，chemical solution is an important factor which affects the rock?s strength and deformation attenuation.
[1] 蔡美峰，何满朝，刘东燕. 岩石力学与工程[M]. 北京：科学出版社，2002：68–72.(CAI Meifeng，HE Manchao，LIU Dongyan. Rock mechanics and engineering[M]. Beijing：Science Press，2002：68–72.(in Chinese))
[2] 李 鹏，刘 建，李国和，等. 水化学作用对砂岩抗剪强度特性影响效应研究[J]. 岩土力学，2011，32(2)：380–386.(LI Peng，LIU Jian，LI Guohe，et al. Experimental study for shear strength characteristics of sandstone under water-rock interaction effects[J]. Rock and Soil Mechanics，2011，32(2)：380–386.(in Chinese))
[3] ATKINSON B K，MEREDITH P G. Stress corrosion cracking of quartz：a note on the influence of chemical environment[J]. Tectonophysics，1981，77(1)：1–11.
[4] 姚华彦，冯夏庭，崔 强，等. 化学溶液及其水压作用下单裂纹灰岩破裂的细观试验[J]. 岩土力学，2009，30(1)：59–78.(YAO Huayan，FENG Xiating，CUI Qiang，et al. Meso-mechanical experimental study of meso-fraeturing process of limestone under coupled chemical corrosion and water pressure[J]. Rock and Soil Mechanics，2009，30(1)：59–78.(in Chinese))
[5] 姚华彦，冯夏庭，崔 强，等. 化学侵蚀下硬脆性灰岩变形和强度特性的试验研究[J]. 岩土力学，2009，30(2)：338–344.(YAO Huayan，FENG Xiating，CUI Qiang，et al. Experimental study of effect of chemical corrosion on strength and deformation of hard brittle limestone[J]. Rock and Soil Mechanics，2009，30(2)：338–344.(in Chinese))
[6] 陈炳瑞，冯夏庭，姚华彦，等. 水化学溶液下灰岩力学特性及神经网络模拟研究[J]. 岩土力学，2010，31(4)：1 173–1 180.(CHEN Bingrui，FENG Xiating，YAO Huayan，et al. Study on mechanical behavior of limestone and simulation using neural network model under different water-chemical environment[J]. Rock and Soil Mechanics，2010，31(4)：1 173–1 180.(in Chinese))
[7] 汤连生，张鹏程，王思敬. 水–岩化学作用的岩石宏观力学效应的试验研究[J]. 岩石力学与工程学报，2002，21(4)：526–531.(TANG Liansheng，ZHANG Pengcheng，WANG Sijing. Testing study on macroscopic mechanic effect of chemical action of water on rocks[J]. Chinese Journal of Rock Mechanics and Engineering，2002，21(4)：526–531.(in Chinese))
[8] 汤连生，王思敬. 岩石水化学损伤的机制及量化方法探讨[J]. 岩石力学与工程学报，2002，21(3)：314–319.(TANG Liansheng，WANG Sijing. Analysis of mechanism and quantitative methods of chemical damage in water-rock interaction[J]. Chinese Journal of Rock Mechanics and Engineering，2002，21(3)：314–319.(in Chinese))
[9] 徐则民，黄润秋，范柱国. 滑坡灾害孕育——激发过程中的水–岩相互作用[J]. 自然灾害学报，2005，14(1)：1–9.(XU Zemin，HUANG Runqiu，FAN Zhuguo. Water-rock interaction in process of landslide preparing and triggering[J]. Journal of Natural Disasters，2005，14(1)：1–9.(in Chinese))
[10] 陈四利，冯夏庭，周 辉. 化学腐蚀下砂岩三轴细观损伤机制及损伤变量分析[J]. 岩土力学，2004，25(9)：1 363–1 367.(CHEN Sili，FENG Xiating，ZHOU Hui. Study on triaxial meso-failure mechanism and damage variables of sandstone under chemical erosion[J]. Rock and Soil Mechanics，2004，25(9)：1 363–1 367.(in Chinese))
[11] 曹 平，杨 慧，江学良，等. 水岩作用下岩石亚临界裂纹的扩展规律[J]. 中南大学学报：自然科学版，2010，41(2)：.649–654.(CAO Ping，YANG Hui，JIANG Xueliang，et al. Subcritical crack growth of rock during water-rock interaction[J]. Journal of Central South University：Science and Technology，2010，41(2)：649–654.(in Chinese))
[12] 李 宁，朱运明，张 平，等. 酸性环境中钙质胶结砂岩的化学损伤模型[J]. 岩土工程学报，2003，25(4)：396–399.(LI Ning，ZHU Yunming，ZHANG Ping，et al. A chemical damage model of sandstone in acid environment[J]. Chinese Journal of Geotechnical Engineering，2003，25(4)：396–399.(in Chinese))
[13] 许 江，彭守建，尹光志，等. 含瓦斯煤岩细观剪切试验装置的研制及应用[J]. 岩石力学与工程学报，2011，30(4)：677–685.(XU Jiang，PENG Shoujian，YIN Guangzhi，et al. Development of meso- shear test equipment for coal rock containing gas and its application[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(4)：677–685.(in Chinese))
[14] 许 江，吴 慧，陆丽丰，等. 不同含水状态下砂岩剪切过程中声发射特性试验研究[J]. 岩石力学与工程学报，2012，31(5)：914–920.(XU Jiang，WU Hui，LU Lifeng，et al. Experimental study of acoustic emission characteristics during shearing process of sandstone under different water contents[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(5)：914–920.(in Chinese))
[15] 许 江，陆丽丰，杨红伟，等. 剪切荷载作用下砂岩细观开裂扩展演化特征研究[J]. 岩石力学与工程学报，2011，30(5)：944–949.(XU Jiang，LU Lifeng，YANG Hongwei，et al. Study of evolution law of microfracturing progress of sandstone under shear loading[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(5)：944–949.(in Chinese))
2012, Vol. 31 
