Loading and Unloading Mechanical Properties and Energy Evolution Mechanism of Red-Bed Mudstone
-
摘要:
为研究红层泥岩的力学特性和能量演化规律，基于5种不同围压梯度（200、250、300、350、400 kPa）及轴压与围压不等速率的应力路径，以四川遂宁地区红层泥岩为例开展了室内循环加卸载试验，得到围压效应对红层泥岩力学特性、总应变能密度、弹性应变能密度、耗散能密度的影响，以及应力-应变与能量之间的演化规律. 研究结果表明：从初始加卸载至试验结束，轴向应力输入的总能量密度、弹性应变能密度以及耗散能密度总体呈先增大后减小的“正态分布”形式；在峰前阶段，弹性应变能密度与耗散能密度间的差值会随着循环加卸载次数的增加而增大；围压的侧限作用提高了试样承载能力，总能量密度、弹性应变能密度以及耗散能密度随着围压的增大而增大；在峰后阶段，当围压≤300 kPa时，耗散能密度低于弹性应变能密度，而围压＞300 kPa时，耗散能密度高于弹性应变能密度，围压增大会进一步抑制试样破坏后弹性应变能密度的释放；相同围压下，随着干湿循环次数的增加，干燥、饱和状态下的抗压强度和弹性应变能密度均呈负相关关系；相同干湿循环次数，干燥状态的抗压强度和弹性应变能密度比饱和状态高，呈正相关关系.
Abstract:To study the mechanical properties and energy evolution law of red-bed mudstone, five different confining pressure gradients (200, 250, 300, 350, and 400 kPa) and different rate stress paths between the axial and confining pressures are used to perform indoor cyclic loading and unloading tests, taking red-bed mudstone in the Suining area, Sichuan Province, as an example. The effects of the confining pressure on the mechanical properties, total strain energy density, elastic strain energy density, and dissipated energy density of the red-bedded mudstone and the evolution law between the stress-strain and energy are obtained. The results show that the total energy density, elastic strain energy density, and dissipated energy density of the axial stress input generally increase first and then decrease in a normal distribution from the initial loading and unloading to the end of the test. During the pre-peak stage, the difference between the elastic strain energy density and the dissipated energy density increases with increasing number of loading and unloading cycles. The confining effect of the confining pressure improves the bearing capacity of the samples, and the total energy density, elastic strain energy density, and dissipated energy density increase with increasing confining pressure. During the post-peak stage, when the confining pressure ≤ 300 kPa, the dissipated energy density is lower than the elastic strain energy density; meanwhile, when the confining pressure > 300 kPa, the dissipated energy density is higher than the elastic strain energy density, indicating that increasing the confining pressure further inhibits the release of elastic strain energy density after failure. Under the same confining pressure, the compressive strength and elastic strain energy density in the dry and saturated states are negatively correlated with the increase in the number of wet-dry cycles. For the same number of dry and wet cycles, the compressive strength and elastic strain energy density in the dry state are higher than those in the saturated state, showing a positive correlation.
-
Key words:
- cyclic loading and unloading /
- energy density /
- energy evolution /
- dissipation energy /
- red-bed mudstone
-
图 3 三轴加卸载试验的应力路径
Figure 3. Schematic diagram of stress path of triaxial loading and unloading test
图 6 三轴循环加卸载全过程应力-应变曲线
Figure 6. Stress-strain curves of triaxial cyclic loading and unloading
图 8 加卸载应力-应变包络曲线示意
Figure 8. Schematic diagram of the stress-strain envelope curve of loading and unloading
图 10 加卸载应力-应变包络曲线示意
Figure 10. Schematic diagram of the stress-strain envelope curve of loading and unloading
图 11 循环加卸载岩样能量密度计算
Figure 11. Calculation of energy density of cyclic loading and unloading rock samples
图 13 干燥状态应力-应变与能量密度关系
Figure 13. Relationships between stress-strain and energy density in the dry state
图 14 饱和状态应力-应变与能量密度关系
Figure 14. Relationships between stress-strain and energy density in saturated state
表 1 岩样基本物理性质
Table 1. Basic physical properties of rock samples
试样编号 天然含
水率/%黏聚力/
kPa内摩擦
角/（°）天然密度/
（g·cm−3）E1 11.4 642 40.6 2.12 E2 12.3 636 39.1 2.04 E3 13.2 618 37.7 1.98 
下载: 导出CSV
表 2 不同围压卸荷试验结果
Table 2. Results of different confining pressure unloading tests
试样
编号平均初
始围压/
kPa平均破
坏围压/
kPa平均抗
剪强度/
kPa平均泊
松比平均剪
切模量/
kPaE4、E5 200 75.0 634 0.31 238 E6、E7 250 62.5 702 0.33 265 E8、E9 300 88.0 834 0.33 315 E10、E11 350 134.0 871 0.31 326 E12、E13 400 174.0 983 0.32 382
下载: 导出CSV
-
[1] 谢和平,彭瑞东,鞠杨,等. 岩石破坏的能量分析初探[J]. 岩石力学与工程学报,2005,24(15): 2603-2608. doi: 10.3321/j.issn:1000-6915.2005.15.001XIE Heping, PENG Ruidong, JU Yang, et al. On energy analysis of rock failure[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(15): 2603-2608. doi: 10.3321/j.issn:1000-6915.2005.15.001 [2] 谢和平,彭瑞东,鞠杨. 岩石变形破坏过程中的能量耗散分析[J]. 岩石力学与工程学报,2004,23(21): 3565-3570. doi: 10.3321/j.issn:1000-6915.2004.21.001XIE Heping, PENG Ruidong, JU Yang. Energy dissipation of rock deformation and fracture[J]. Chinese Journal of Rock Mechanics and Engineering, 2004, 23(21): 3565-3570. doi: 10.3321/j.issn:1000-6915.2004.21.001 [3] 尤明庆,华安增. 岩石试样破坏过程的能量分析[J]. 岩石力学与工程学报,2002,21(6): 778-781. doi: 10.3321/j.issn:1000-6915.2002.06.004YOU Mingqing, HUA Anzeng. Energy analysis on failure process of rock specimens[J]. Chinese Journal of Rock Mechanics and Engineering, 2002, 21(6): 778-781. doi: 10.3321/j.issn:1000-6915.2002.06.004 [4] 谢和平,鞠杨,黎立云. 基于能量耗散与释放原理的岩石强度与整体破坏准则[J]. 岩石力学与工程学报,2005,24(17): 3003-3010. doi: 10.3321/j.issn:1000-6915.2005.17.001XIE Heping, JU Yang, LI Liyun. Criteria for strength and structural failure of rocks based on energy dissipation and energy release principles[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(17): 3003-3010. doi: 10.3321/j.issn:1000-6915.2005.17.001 [5] GAZIEV E. Rupture energy evaluation for brittle materials[J]. International Journal of Solids and Structures, 2001, 38(42/43): 7681-7690. [6] 杨永明,鞠杨,陈佳亮,等. 三轴应力下致密砂岩的裂纹发育特征与能量机制[J]. 岩石力学与工程学报,2014,33(4): 691-698. doi: 10.13722/j.cnki.jrme.2014.04.005YANG Yongming, JU Yang, CHEN Jialiang, et al. Cracks development features and energy mechanism of dense sandstone subjected to triaxial stress[J]. Chinese Journal of Rock Mechanics and Engineering, 2014, 33(4): 691-698. doi: 10.13722/j.cnki.jrme.2014.04.005 [7] MUNOZ H, TAHERI A, CHANDA E K. Rock drilling performance evaluation by an energy dissipation based rock brittleness index[J]. Rock Mechanics and Rock Engineering, 2016, 49(8): 3343-3355. doi: 10.1007/s00603-016-0986-0 [8] 田勇,俞然刚. 不同围压下灰岩三轴压缩过程能量分析[J]. 岩土力学,2014,35(1): 118-122,129. doi: 10.16285/j.rsm.2014.01.019TIAN Yong, YU Rangang. Energy analysis of limestone during triaxial compression under different confining pressures[J]. Rock and Soil Mechanics, 2014, 35(1): 118-122,129. doi: 10.16285/j.rsm.2014.01.019 [9] 黄达,谭清,黄润秋. 高应力强卸荷条件下大理岩损伤破裂的应变能转化过程机制研究[J]. 岩石力学与工程学报,2012,31(12): 2483-2493. doi: 10.3969/j.issn.1000-6915.2012.12.012HUANG Da, TAN Qing, HUANG Runqiu. Mechanism of strain energy conversion process for marble damage and fracture under high stress and rapid unloading[J]. Chinese Journal of Rock Mechanics and Engineering, 2012, 31(12): 2483-2493. doi: 10.3969/j.issn.1000-6915.2012.12.012 [10] 张黎明,高速,王在泉,等. 大理岩加卸荷破坏过程的能量演化特征分析[J]. 岩石力学与工程学报,2013,32(8): 1572-1578.ZHANG Liming, GAO Su, WANG Zaiquan, et al. Analysis of marble failure energy evolution under loading and unloading conditions[J]. Chinese Journal of Rock Mechanics and Engineering, 2013, 32(8): 1572-1578. [11] MENG Q B, ZHANG M W, ZHANG Z Z, et al. Experimental research on rock energy evolution under uniaxial cyclic loading and unloading compression[J]. Geotechnical Testing Journal, 2018, 41(4): 717-729. [12] MENG Q B, ZHANG M W, HAN L J, et al. Effects of acoustic emission and energy evolution of rock specimens under the uniaxial cyclic loading and unloading compression[J]. Rock Mechanics and Rock Engineering, 2016, 49(10): 3873-3886. doi: 10.1007/s00603-016-1077-y [13] 王向宇,周宏伟,钟江城,等. 三轴循环加卸载下深部煤体损伤的能量演化和渗透特性研究[J]. 岩石力学与工程学报,2018,37(12): 2676-2684. doi: 10.13722/j.cnki.jrme.2018.0697WANG Xiangyu, ZHOU Hongwei, ZHONG Jiangcheng, et al. Study on energy evolution and permeability characteristics of deep coal damage under triaxial cyclic loading and unloading conditions[J]. Chinese Journal of Rock Mechanics and Engineering, 2018, 37(12): 2676-2684. doi: 10.13722/j.cnki.jrme.2018.0697 [14] 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. doi: 10.16285/j.rsm.2018.2166YANG Xiaobin, CHENG Hongming, LÜ Jiaqi, et al. Energy consumption ratio evolution law of sandstones under triaxial cyclic loading[J]. Rock and Soil Mechanics, 2019, 40(10): 3751-3757,3766. doi: 10.16285/j.rsm.2018.2166 [15] 王晓强,姚华彦,代领,等. 皖南红层软岩崩解特性试验分析[J]. 地下空间与工程学报,2021,17(3): 683-691.WANG Xiaoqiang, YAO Huayan, DAI Ling, et al. Experimental study on slaking characteristics of red-bed soft rock in southern Anhui Province[J]. Chinese Journal of Underground Space and Engineering, 2021, 17(3): 683-691. [16] 纪宇,梁庆国,郭俊彦,等. 红层软岩地区高速铁路深路堑基底变形规律研究[J]. 铁道科学与工程学报,2021,18(3): 572-580. doi: 10.19713/j.cnki.43-1423/u.T20200425JI Yu, LIANG Qingguo, GUO Junyan, et al. Study on deformation law of deep foundation of high speed railway in red layer soft rock area[J]. Journal of Railway Science and Engineering, 2021, 18(3): 572-580. doi: 10.19713/j.cnki.43-1423/u.T20200425 [17] 李安润,邓辉,王小雪,等. 饱水-失水循环条件下红层泥岩蠕变特性及本构模型研究[J]. 工程地质学报,2021,29(3): 843-850. doi: 10.13544/j.cnki.jeg.2020-098LI Anrun, DENG Hui, WANG Xiaoxue, et al. Research on creep characteristics and constitutive model of red bed mudstone under saturated-dehydrated cycle[J]. Journal of Engineering Geology, 2021, 29(3): 843-850. doi: 10.13544/j.cnki.jeg.2020-098 [18] 周其健,马德翠,邓荣贵,等. 地热系统作用下红层软岩力学性能试验研究[J]. 岩土力学,2020,41(10): 3333-3342. doi: 10.16285/j.rsm.2020.0035ZHOU Qijian, MA Decui, DENG Ronggui, et al. Experimental study on mechanical properties of red-layer soft rock in geothermal systems[J]. Rock and Soil Mechanics, 2020, 41(10): 3333-3342. doi: 10.16285/j.rsm.2020.0035 [19] 余云燕,罗崇亮,包得祥,等. 兰州地区红层泥岩物理力学特性试验[J]. 兰州交通大学学报,2019,38(5): 1-6. doi: 10.3969/j.issn.1001-4373.2019.05.001YU Yunyan, LUO Chongliang, BAO Dexiang, et al. Experimental study on physical and mechanical properties of red mudstone in Lanzhou area[J]. Journal of Lanzhou Jiaotong University, 2019, 38(5): 1-6. doi: 10.3969/j.issn.1001-4373.2019.05.001 [20] 徐颖,李成杰,郑强强,等. 循环加卸载下泥岩能量演化与损伤特性分析[J]. 岩石力学与工程学报,2019,38(10): 2084-2091. doi: 10.13722/j.cnki.jrme.2019.0153XU Ying, LI Chengjie, ZHENG Qiangqiang, et al. Analysis of energy evolution and damage characteristics of mudstone under cyclic loading and unloading[J]. Chinese Journal of Rock Mechanics and Engineering, 2019, 38(10): 2084-2091. doi: 10.13722/j.cnki.jrme.2019.0153 [21] 秦涛,段燕伟,刘志,等. 砂岩循环加卸载过程能量的演化与损伤特性[J]. 黑龙江科技大学学报,2020,30(1): 8-15. doi: 10.3969/j.issn.2095-7262.2020.01.002QIN Tao, DUAN Yanwei, LIU Zhi, et al. Energy evolution and damage characteristics of sandstone under cyclic loading and unloading[J]. Journal of Heilongjiang University of Science and Technology, 2020, 30(1): 8-15. doi: 10.3969/j.issn.2095-7262.2020.01.002 [22] 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. doi: 10.13722/j.cnki.jrme.2020.0208MENG Qingbin, WANG Congkai, HUANG Bingxiang, et al. Rock energy evolution and distribution law under triaxial cyclic loading and unloading conditions[J]. Chinese Journal of Rock Mechanics and Engineering, 2020, 39(10): 2047-2059. doi: 10.13722/j.cnki.jrme.2020.0208 [23] 陈纪昌. 库区红层泥岩水化特性及干湿循环作用下的渐进损伤研究[J]. 中国农村水利水电,2021(3): 143-147,152. doi: 10.3969/j.issn.1007-2284.2021.03.028CHEN Jichang. Research on the hydration characteristics and progressive damage of red bed mudstone under dry-wet cycle in reservoir areas[J]. China Rural Water and Hydropower, 2021(3): 143-147,152. doi: 10.3969/j.issn.1007-2284.2021.03.028 [24] 国家质量技术监督局, 中华人民共和国住建部. 工程岩体试验方法标准: GB/T 50266—2013[S]. 北京: 中国计划出版社, 2013. -
下载:
点击查看大图
计量
- 文章访问数: 302
- HTML全文浏览量: 147
- PDF下载量: 34
- 被引次数: 0