作者：蔡国军1,2, 孙文鹏1,2, 陈锡锐1,2, 杨森林1,2, 贾俊3, 李林1,2
作者单位：1. 成都理工大学 地质灾害防治与地质环境保护国家重点实验室，四川 成都 610059;
2. 成都理工大学 地质工程国家级实验教学示范中心，四川 成都 610059;
3. 中国地质调查局西安地质调查中心/西北地质科技创新中心自然资源部黄土地质灾害重点实验室，陕西 西安 710054
关键词：岩石力学;砂岩;循环加卸载;损伤力学特性;滞回环特性
摘要：
通过选取陕西省略阳市某滑坡表层的中风化砂岩进行静态单轴压缩试验与三轴循环加卸载试验，研究低围压循环加卸载条件下岩石的损伤力学特性，得到力学参数、损伤参数、滞回环面积等随循环过程的演化规律及循环荷载作用下砂岩的变形破坏机制。结果表明：循环加卸载试验过程中，围压增强砂岩抵抗变形破坏能力，随着围压增大，动弹性模量明显增大而动泊松比逐渐降低，砂岩试样内凹现象逐渐“模糊”；滞回环面积受围压与轴向载荷影响明显，与围压变化呈负相关，与轴向载荷变化呈正相关，轴向载荷增大时，不可逆应变逐渐累积，砂岩损伤加剧；砂岩内部原始裂隙在初始较低循环荷载作用下压密，后过渡到弹性变形与裂纹稳定扩展阶段，随着试验进行，裂纹加速演化不稳定扩张，岩样逐渐变形失稳破坏。
Research on damage mechanical characteristics of sandstone under graded cyclic loading and unloading
CAI Guojun1,2, SUN Wenpeng1,2, CHEN Xirui1,2, YANG Senlin1,2, JIA Jun3, LI Lin1,2
1. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu 610059, China;
2. National Geological Engineering Experimental Teaching Demonstration Center, Chengdu University of Technology, Chengdu 610059, China;
3. Key Laboratory for Geo-hazards in Loess Area, MNR Xi'an Center of China Geological Survey/Northwest China Center for Geoscience Innovation, Xi'an 710054, China
Abstract: By selecting a medium-weathered sandstone from a landslide surface layer in Lueyang City, Shanxi Province for static uniaxial compression tests and triaxial cyclic loading and unloading tests, the author studies the mechanical properties of the damage under the cyclic loading and unloading conditions with low circumferential pressure, thus obtaining the evolution of mechanical parameters, damage parameters, the area of hysteresis loop and other parameters with the cyclic process, and the deformation and damage mechanism of the sandstone under cyclic loading. The results show that: during the cyclic loading and unloading tests, the circumferential pressure enhances the resistance of sandstone to deformation and damage, and the dynamic elastic modulus increases significantly with the increase of circumferential pressure while the dynamic Poisson's ratio decreases gradually, and the concavity of sandstone specimens is gradually "blurred"; the area of hysteresis loop is affected by the circumferential pressure and axial load, and is negatively correlated with the change of circumferential pressure and positively correlated with the change of axial load. When the axial load increases, the irreversible strain gradually accumulates and the damage of sandstone intensifies; the original fracture inside the sandstone is compressed and dense under the initial low cyclic load, and then transitions to the stage of elastic deformation and stable expansion of fracture, and as the test proceeds, the fracture accelerates the evolution of unstable expansion and the rock sample gradually deforms and destabilizes.
Keywords: rock mechanics;sandstone;cyclic loading and unloading;damage mechanical characteristics;hysteretic loop characteristics
2023, 49(1):161-168 收稿日期: 2021-06-25;收到修改稿日期: 2021-09-09
基金项目: 自然资源部中国地质调查局地质调查项目（DD20190714）；国家自然科学基金（41202209, 41977255）；国家重点实验室自主课题（SKLGP2019Z017）；四川省科技计划（2019YJ0403）资助
作者简介: 蔡国军(1982-),男,江西抚州市人,高级实验师,硕士,研究方向为地质工程和岩土工程
参考文献
[1] 黄润秋, 李为乐. “5.12”汶川大地震触发地质灾害的发育分布规律研究[J]. 岩石力学与工程学报, 2008, 27(12): 2585-2592
[2] 葛修润, 蒋宇, 卢允德, 等. 周期荷载作用下岩石疲劳变形特性试验研究[J]. 岩石力学与工程学报, 2003, 22(10): 1581-1585
[3] 邓华锋, 胡玉, 李建林, 等. 循环加卸载过程中砂岩能量耗散演化规律[J]. 岩石力学与工程学报, 2016, 35(增1): 2869-2875
[4] 周家文, 杨兴国, 符文熹, 等. 脆性岩石单轴循环加卸载试验及断裂损伤力学特性研究[J]. 岩石力学与工程学报, 2010, 29(6): 1172-1183
[5] 杨春和, 马洪岭, 刘建锋. 循环加、卸载下盐岩变形特性试验研究[J]. 岩土力学, 2009, 30(12): 3562-3568
[6] EBERHARDT E, STEAD D, STIMPSON B. Quantifying progressive pre-peak brittle fracture damage in rock during uniaxial compression[J]. International Journal of Rock Mechanics and Mining Sciences, 1999, 36(3): 361-380
[7] EBERHARDT E, STEAD D, STIMPSON B, et al. Identifying crack initiation and propagation thresholds in brittle rock[J]. Canadian Geotechnical Journal, 1998, 35(2): 222-233
[8] 李宏岩. 低温下砂岩动态力学特性试验研究[J]. 中国测试, 2022, 48(6): 148-152
[9] 彭瑞东, 鞠杨, 高峰, 等. 三轴循环加卸载下煤岩损伤的能量机制分析[J]. 煤炭学报, 2014, 39(2): 245-252
[10] 杨小彬, 程虹铭, 吕嘉琦, 等. 三轴循环荷载下砂岩损伤耗能比演化特征研究[J]. 岩土力学, 2019, 40(10): 3751-3757+3766
[11] 苗胜军, 刘泽京, 赵星光, 等. 循环荷载下北山花岗岩能量耗散与损伤特征[J]. 岩石力学与工程学报, 2021, 40(5): 928-938
[12] 孟庆彬, 王从凯, 黄炳香, 等. 三轴循环加卸载条件下岩石能量演化及分配规律[J]. 岩石力学与工程学报, 2020, 39(10): 2047-2059
[13] 李子运, 吴光, 黄天柱, 等. 三轴循环荷载作用下页岩能量演化规律及强度失效判据研究[J]. 岩石力学与工程学报, 2018, 37(3): 662-670
[14] 荣笛, 孟陆波. 三轴循环荷载下饱和板岩的滞后特性研究[J]. 中国测试, 2021, 47(6): 57-62
[15] 赵星光, 李鹏飞, 马利科, 等. 循环加、卸载条件下北山深部花岗岩损伤与扩容特性[J]. 岩石力学与工程学报, 2014, 33(9): 1740-1748
[16] 李鹏飞, 赵星光, 郭政, 等. 北山花岗岩在三轴压缩条件下的强度参数演化[J]. 岩石力学与工程学报, 2017, 36(7): 1599-1610
[17] 赵星光, 马利科, 苏锐, 等. 北山深部花岗岩在压缩条件下的破裂演化与强度特性[J]. 岩石力学与工程学报, 2014, 33(增2): 3665-3675
[18] 黄正均, 赵星光, 李远, 等. 体积应变率对北山花岗岩疲劳特性的影响[J]. 岩石力学与工程学报, 2018, 37(5): 1161-1168
[19] BIENIAWSKI Z T, BERNEDE M J. Suggested methods for determining the uniaxial compressive strength and deformability of rock materials[J]. International Journal of Rock Mechanics and Mining Sciences, 1979, 16(2): 135-140
[20] 蔡国军, 赵大安, 冯伟强, 等. 不同围压条件下千枚岩宏观破坏与微观破裂特征分析[J]. 中国测试, 2021, 47(6): 45-50
