Study on the influence of stress and water content on creep characteristics of fractured granite
WANG Chunping1，2，LIAO Yilin3，LIU Jianfeng3，LIU Jian1，2，ZHAO Xingguang1，2，CHEN Liang1，2，WANG Lu3，4
(1. Beijing Research Institute of Uranium Geology，Beijing 100029，China；2. CAEA Innovation Center for Geological Disposal of High-Level Radioactive Waste，Beijing 100029，China；3. College of Water Resource and Hydropower，Sichuan University，Chengdu，Sichuan 610065，China；4. School of Architecture and Civil Engineering，Xihua University，Chengdu，Sichuan 610039，China)
Abstract：To investigate the effects of stress and water content on the creep characteristics of fractured granite，a series of creep tests were carried out using the high temperature triaxial rheological test system for rock. The experiment mainly consists of the multi-stress creep tests under different confining pressures，and uniaxial creep tests under different water content. The test samples were intact granite and granite with different inclinational fractures，which were taken from Beishan pre-selected area of Gansu Province for geological disposal of high-level radioactive waste in China. The experimental results indicates that, the lateral deformation of fractured granite presents more significant creep characteristics，and the lateral steady creep strain rate is slightly higher than axial steady creep strain rate. With the increase of the stress level，the axial strain presents a linear growth relationship，while the lateral strain and the axial and lateral steady creep strain rates all show an exponential function growth relationship. Under the condition of the same confining pressure and the same deviatoric stress，the larger the fracture inclination angle is，the larger the axial and lateral strains are，and the higher the axial and lateral steady creep rates are. Under saturated state，the steady creep rate of granite is significantly increased，and the rock mass is more prone to deformation under the same stress，resulting in the failure of granite under lower creep load or shorter creep duration. When the inclination angle θ is 45° or 60°，the failure time of saturated sample is only 1.05‰ or 0.84‰ of the failure time of dry sample. The failure modes of fractured granite can be divided into three types：causing new fractures which cut across the pre-made fracture(θ = 30°)，slipping of the pre-made fracture(θ = 60°) and the compound failure of the first two forms(θ = 45°). The confining pressure of 10 MPa，and the dry or saturated state have no significant influence on the creep failure form of fractured granite.
王春萍1，2，廖益林3，刘建锋3，刘 健1，2，赵星光1，2，陈 亮1，2，王 璐3，4. 应力及含水状态对裂隙花岗岩蠕变特性的影响研究[J]. 岩石力学与工程学报, 2024, 43(4): 907-917.
WANG Chunping1，2，LIAO Yilin3，LIU Jianfeng3，LIU Jian1，2，ZHAO Xingguang1，2，CHEN Liang1，2，WANG Lu3，4. Study on the influence of stress and water content on creep characteristics of fractured granite. , 2024, 43(4): 907-917.
[1] 陈世万，王贵宾，杨春和，等. 高放废物处置库围岩开挖损伤区研究的关键问题及进展[J]. 辐射防护，2019，39(2)：137–149.(CHEN Shiwan，WANG Guibin，YANG Chunhe，et al. Key issues and research progress of excavation damage zone in surrounding rocks of high-level radioactive waste disposal repositories[J]. Radiation Protection，2019，39(2)：137–149.(in Chinese))
[2] 黄润秋，黄 达，段绍辉，等. 锦屏Ⅰ级水电站地下厂房施工期围岩变形开裂特征及地质力学机制研究[J]. 岩石力学与工程学报，2011，30(1)：23–35.(HUANG Runqiu，HUANG Da，DUAN Shaohui，et al. Geomechanics mechanism and characteristics of surrounding rock mass deformation failure in construction phase for underground powerhouse of Jinping I hydropower station[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(1)：23–35.(in Chinese))
[3] LOCKNER D A，BYERLEE J D，KUKSENKO V，et al. Observations of quasistatic fault growth from acoustic emissions[M]. EVANS B，WONG T F，ed. London，US：Academic Press，1992：3–31.
[4] BRANTUT N，HEAP M J，MEREDITH P G，et al. Time-dependent cracking and brittle creep in crustal rocks：A review[J]. Journal of Structural Geology，2013，52：17–43.
[5] WANG C P，LIU J F，CHEN L，et al. Mechanical behaviour and damage evolution of Beishan granite considering the transient and time-dependent effects of excavation unloading[J]. European Journal of Environmental and Civil Engineering，2022，26(8)：3 187–3 203.
[6] WANG C P，LIU J F，LIU J. Effect of stress condition on the creep behaviour of Beishan granite[C]// China Rock 2020. [S. l.]：IOP Publishing，2020：032005.
[7] HEAP M J，BAUD P，MEREDITH P G，et al. Brittle creep in basalt and its application to time-dependent volcano deformation[J]. Earth and Planetary Science Letters，2011，307：71–82.
[8] TANG S B，LI J M，DING S，et al. The influence of water-stress loading sequences on the creep behavior of granite[J]. Bulletin of Engineering Geology and the Environment，2022，81：482.
[9] ZHA E S，ZHANG Z T，ZHANG R，et al. Long-term mechanical and acoustic emission characteristics of creep in deeply buried Jinping marble considering excavation disturbance[J]. International Journal of Rock Mechanics and Mining Sciences，2021，139：104603.
[10] 邵珠山，靳冬冬，陈浩哲，等. 含水状态对石英砂岩单轴分级蠕变性能影响研究[J]. 应用力学学报，2021，38(5)：1 839–1 845.(SHAO Zhushan，JIN Dongdong，CHEN Haozhe，et al. Investigation on creep properties of different moisture state quartz sandstone by multi-stage test[J]. Chinese Journal of Applied Mechanics，2021，38(5)：1 839–1 845.(in Chinese))
[11] MISHRA B，VERMA P. Uniaxial and triaxial single and multistage creep tests on coal-measure shale rocks[J]. International Journal of Coal Geology，2015，137：55–65.
[12] 胡 波，杨圣奇，徐 鹏，等. 单裂隙砂岩蠕变模型参数时间尺度效应及颗粒流数值模拟研究[J]. 岩土工程学报，2019，41(5)：864–873.(HU Bo，YANG Shengqi，XU Peng，et al. Time-scale effect of the creep model parameters and particle flow simulation of sandstone with a single crack[J]. Chinese Journal of Geotechnical Engineering，2019，41(5)：864–873.(in Chinese))
[13] 杨 超，黄 达，蔡 睿，等. 张开穿透型单裂隙岩体三轴卸荷蠕变特性试验[J]. 岩土力学，2018，39(1)：53–62.(YANG Chao，HUANG Da，CAI Rui，et al. Triaxial unloading creep tests on rock mass with an open and penetrating flaw[J]. Rock and Soil Mechanics，2018，39(1)：53–62.(in Chinese))
[14] 杨 超，黄 达，黄润秋，等．断续双裂隙砂岩三轴卸荷蠕变特性试验及损伤蠕变模型[J]．煤炭学报，2016，41(9)：2 203–2 211. (YANG Chao，HUANG Da，HUANG Runqiu，et al. Experimental study on the triaxial unloading creep characteristics of stone with two pre-existing cracks and its damage creep model[J]. Journal of China Coal Society，2016，41(9)：2 203–2 211.(in Chinese))
[15] 杨 超，冯振华，王 鑫，等. 多级时效荷载下双裂隙砂岩变形与破裂特征试验研究[J]. 岩石力学与工程学报，2017，36(9)：2 092–2 101.(YANG Chao，FENG Zhenhua，WANG Xin，et al. Experimental research on deformation and crack coalescence properties of sandstone containing two pre-existing fissures under multistage time-dependent loading[J]. Chinese Journal of Rock Mechanics and Engineering，2017，36(9)：2 092–2 101.(in Chinese))
[16] 刘德峰，刘鹏涛，张臻悦，等. 轴压水压耦合作用下裂隙砂岩蠕变特性[J]. 工程科学与技术，2021，53(1)：94–103.(LIU Defeng，LIU Pengtao，ZHANG Zhenyue，et al. Creep Characteristics of fractured sandstone under the coupling action of axial compression and hydraulic pressure[J]. Advanced Engineering Sciences，2021，53(1)：94–103.(in Chinese))
[17] ZHAO Y L，ZHANG L Y，WANG W J，et al. Creep behavior of intact and cracked limestone under multi-level loading and unloading cycles[J]. Rock Mechanics and Rock Engineering，2017，50(6)：1–16.
[18] CHU Z F，WU Z J，WANG Z Y，et al. Micro-mechanism of brittle creep in saturated sandstone and its mechanical behavior after creep damage[J]. International Journal of Rock Mechanics and Mining Science，2022，149：104994.
[19] 陈 英，谢 辉，杨 俊，等. 真实水压作用下裂隙大理岩蠕变特性试验研究[J]. 工程科学与技术，2021，53(4)：149–157.(CHEN Ying，XIE Hui，YANG Jun，et al. Experimental study on creep properties of fractured marble under water pressure[J]. Advanced Engineering Sciences，2021，53(4)：149–157.(in Chinese))
[20] 陈 亮，刘建锋，王春萍，等. 不同温度及应力状态下北山花岗岩蠕变特征研究[J]. 岩石力学与工程学报，2015，34(6)：1 228–1 235. (CHEN Liang，LIU Jianfeng，WANG Chunping，et al. Creep behavior of the Beishan granite under different temperature and stress conditions[J]. Chinese Journal of Rock Mechanics and Engineering，2015，34(6)：1 228–1 235.(in Chinese))
[21] CHEN L，WANG C P，LIU J F，et al. Effects of temperature and stress on the time-dependent behavior of Beishan granite[J]. International Journal of Rock Mechanics and Mining Sciences，2017，93：316–323.
[22] LIN Q X，LIU Y M，THAM L G，et al. Time-dependent strength degradation of granite[J]. International Journal of Rock Mechanics and Mining Sciences，2009，46：1 103–1 114.
[23] LIU J F，LUO X，FENG G，et al. Creep characteristics of thermally-stressed Beishan granite under triaxial compression[J]. International Journal of Rock Mechanics and Mining Sciences，2023，162：105302.
[24] WANG J，CHEN L，SU R，et al. The Beishan underground research laboratory for geological disposal of high-level radioactive waste in China：Planning，Site selection，site characterization and in situ tests[J]. Journal of Rock Mechanics and Geotechnical Engineering，2018，10：411–435.
[25] 夏 冬，杨天鸿，王培涛，等. 干燥及饱和岩石循环加卸载过程中声发射特征试验研究[J]. 煤炭学报，2014，39(7)：1 243–1 247.(XIA Dong，YANG Tianhong，WANG Peitao，et al. Experimental study of acoustic emission characteristics of dry and saturated rock during cyclic loading and unloading process[J]. Journal of China Coal Society，2014，39(7)：1 243–1 247.(in Chinese))
[26] 贾 蓬，卢佳亮，毛松泽，等. 不同饱和度冻融砂岩动态冲击压缩特性及损伤机制研究[J]. 岩石力学与工程学报，2023，42(12)： 2 908–2 918.(JIA Peng，LU Jialiang，MAO Songze，et al. Dynamic impact compression characteristics and damage mechanism of freeze-thaw sandstones with different saturation levels[J]. Chinese Journal of Rock Mechanics and Engineering，2023，42(12)：2 908– 2 918.(in Chinese))
2024, Vol. 43 
