花岗岩滞后应变型岩爆模拟试验中破坏特征分析

doi:10.3724/1000-6915.jrme.2024.0601

Abstract
Figure/Table
References (0)
Related Citation (15)

Download: PDF (2846 KB) HTML (1 KB)
Export: BibTeX | EndNote (RIS)

Abstract Strain-induced rock burst can be classified into instantaneous and delayed types according to rockburst causes. In this paper, a real three-axis unloading and delayed strain-induced rock burst simulation experiment was conducted on granite using a deep-seated rock burst simulation experimental system. Based on the signal collected by the acoustic emission system, quantitative analysis of parameters and waveform was performed. At the same time, high-speed photography was used to record the process of rock burst destruction, and the characteristics of rock surface failure were observed. The occurrence mechanism of delayed strain-induced burst in granite rock was revealed from multiple perspectives. The results indicate that granite occurred severe delayed type rock burst under the special stress loading condition which referred to loading in three directions, unloading one single face and then loading in vertical direction. Before the granite occurred rock burst, the AE ringing counts had an intensive and explosive growth while the AE b-value showed a sudden continuous decline. During the rock burst phase, the proportion of AE signals with high amplitude in low-frequency showed a growth trend, indicating there occurred rapid development of large-scale cracks with higher energy release in rock. Based on AE cluster analysis of RA-AF distribution division, it was found that there appeared tensile and shear composite failure, and both the amount of tensile and shear type cracks decreased at first and then had an obvious increase until final decreased. Tensile-shear crack ratio increased and then decreased, remained stable, rose and then dropped again to the lowest value. The fractal of AE ringing count rate presented dense distribution in a short period of time before burst, and had a sudden decrease sharply after the continuous vibration. Compared the warning information of rock burst determined by AE ringing count, b-value, major frequency, RA-AF distribution and AE fractal dimension, the average precursor response coefficients were 1.18%, 0.94%, 1.50%, 1.45% and 0.91% respectively. Hence, the response time for identifying precursors based on the AE major frequency-amplitude and tensile-shear crack amount and ratio were earlier. They could more finely characterize the complexity of AE signals and reveal the rock fracture mechanism. This study can provide reference for revealing the mechanism of delayed type rock burst occurrence and establishing disaster warning methods.

Key words： rock mechanics delayed type strain rock burst granite acoustic emission precursor

	Service

	E-mail this article
	Add to my bookshelf
	Add to citation manager
	E-mail Alert
	RSS
	Articles by authors
	WANG Hongjian1
	2
	ZHANG Jinran1
	LIU Dongqiao3
	ZHAO Fei1
	3
	SHI Xiaoshan2
	4
	REN Fuqiang5
	WANG Chuang1

Cite this article:

WANG Hongjian1,2,ZHANG Jinran1, et al. Analysis of failure characteristics in delayed strain-type rock burst simulation test on granite[J]. , 2025, 44(6): 1481-1499.

URL:

https://rockmech.whrsm.ac.cn/EN/10.3724/1000-6915.jrme.2024.0601 OR https://rockmech.whrsm.ac.cn/EN/Y2025/V44/I6/1481

[32]	甘一雄，吴顺川，任义，等. 基于声发射上升时间/振幅与平均频率值的花岗岩劈裂破坏评价指标研究[J]. 岩土力学，2020，41(7)：2 324-2 332.(GAN Yixiong，WU Shunchuan，REN Yi，et al. Evaluation indexes of granite splitting failure based on RA and AF of AE parameters[J]. Rock and Soil Mechanics，2020，41(7)：2 324- 2 332.(in Chinese))
[19]	苗金丽，何满潮，李德建，等. 花岗岩应变岩爆声发射特征及微观断裂机制[J]. 岩石力学与工程学报，2009，28(8)：1 593-1 603. (MIAO Jinli，HE Manchao，LI Dejian，et al. Acoustic emission characteristics of granite under strain rockburst test and its micro-fracture mechanism[J]. Chinese Journal of Rock Mechanics and Engineering，2009，28(8)：1 593-1 603.(in Chinese))
[1]	何满潮. 深部的概念体系及工程评价指标[J]. 岩石力学与工程学报，2005，24(16)：2 854-2 858.(HE Manchao. Conception system and evaluation indexs for deep engineering[J]. Chinese Journal of Rock Mechanics and Engineering，2005，24(16)：2 854-2 858.(in Chinese))
[33]	关庆圆. 钢筋混凝土梁损伤过程的声发射多参数分析及损伤识别[硕士学位论文][D]. 扬州：扬州大学，2023.(GUAN Qingyuan. Acoustic emission multi-parameter analysis and damage identification of reinforced concrete beam damage process[M. S. Thesis][D]. Yangzhou：Yangzhou University，2023.(in Chinese))
[20]	SU G S，GAN W，ZHAI S B，et al. Acoustic emission precursors of static and dynamic instability for coarse-grained hard rock[J]. Journal of Central South University，2020，27(10)：2 883-2 898.
[2]	何满潮，苗金丽，李德建，等. 深部花岗岩试样岩爆过程实验研究[J]. 岩石力学与工程学报，2007，184(5)：865-876.(HE Manchao，MIAO Jinli，LI Dejian，et al. Experimental study on rockburst processes of granite specimen at great depth[J]. Chinese Journal of Rock Mechanics and Engineering，2007，184(5)：865-876.(in Chinese))
[34]	GRASSBERGER P，PROCACCIA I. Estimation of the Kolmogorov entropy from a chaotic signal[J]. Physical Review A，1983，28(4)：2 591.
[21]	何满潮，赵菲，张昱，等. 瞬时应变型岩爆模拟试验中花岗岩主频特征演化规律分析[J]. 岩土力学，2015，36(1)：1-8.(HE Manchao，ZHAO Fei，ZHANG Yu，et al. Feature evolution of dominant frequency components in acoustic emissions of instantaneous strain-type granitic rockburst simulation tests[J]. Rock and Soil Mechanics，2015，36(1)：1-8.(in Chinese))
[3]	张文东. 深埋岩体隧洞滞后型岩爆特征及其时效变形诱发机理研究[硕士学位论文][D]. 大连：大连理工大学，2015.(ZHANG Wendong. Study in characteristics and time-dependent deformation mechanism of delayed rockburst in deep tunnel in rock mass[M. S. Thesis][D]. Dalian：Dalian University of Technology，2015.(in Chinese))
[22]	孙飞跃，郭佳奇，刘希亮，等. 真三轴单面卸荷条件下中间主应力对深埋洞室岩爆影响特征[J]. 煤炭学报，2024，49(增1)：220-235. (SUN Feiyue，GUO Jiaqi，LIU Xiliang，et al. Study on the influence of intermediate principal stress on rockburst in deep cavern under true triaxial condition with single face unloading[J]. Journal of China Coal Society，2024，49(Supp.1)：220-235.(in Chinese))
[35]	丛宇，冯夏庭，郑颖人，等. 不同应力路径大理岩声发射破坏前兆的试验研究[J]. 岩土工程学报，2016，38(7)：1 193-1 201.(CONG Yu，FENG Xiating，ZHENG Yingren，et al. Experimental study on acoustic emission failure precursors of marble under different stress paths[J]. Chinese Journal of Geotechnical Engineering，2016，38(7)：1 193-1 201.(in Chinese))
[4]	杨艳霜，周辉，张传庆，等. 大理岩单轴压缩时滞性破坏的试验研究[J]. 岩土力学，2011，32(9)：2 714-2 720.(YANG Yanshuang，ZHOU Hui，ZHANG Chuanqing，et al. Experimental investigation on time-lag failure properties of marble under uniaxial compressive test[J]. Rock and Soil Mechanics，2011，32(9)：2 714-2 720.(in Chinese))
[23]	苏国韶，燕思周，闫召富，等. 真三轴加载条件下岩爆过程的声发射演化特征[J]. 岩土力学，2019，40(5)：1 673-1 682.(SU Guoshao，YAN Sizhou，YAN Zhaofu，et al. Evolution characteristics of acoustic emission in rockburst process under true-triaxial loading conditions[J]. Rock and Soil Mechanics，2019，40(5)：1 673-1 682.(in Chinese))
[5]	WANG C，CAO C，LI C，et al. Experimental investigation on synergetic prediction of granite rockburst using rock failure time and acoustic emission energy[J]. Journal of Central South University，2022，29(4)：1 262-1 273.
[36]	张艳博，梁鹏，田宝柱，等. 花岗岩灾变声发射信号多参量耦合分析及主破裂前兆特征试验研究[J]. 岩石力学与工程学报，2016，35(11)：2 248-2 258.(ZHANG Yanbo，LIANG Peng，TIAN Baozhu，et al. Multi parameter coupling analysis of acoustic emission signals of granite disaster and the precursor characteristics of the main rupture[J]. Chinese Journal of Rock Mechanics and Engineering，2016，35(11)：2 248-2 258.(in Chinese))
[24]	曾强. 不同岩爆倾向灰岩声发射参量分析及破裂特征研究[硕士学位论文][D]. 赣州：江西理工大学，2021.(ZENG Qiang. Analysis of acoustic emission parameters of limestone with different rock burst tendencies and research on fracture characteristics[M. S. Thesis][D]. Ganzhou：Jiangxi University of Science and Technology，2021.(in Chinese))
[6]	王学滨，潘一山，杜亚志. 围压对圆形巷道岩爆过程中声发射及能量释放规律的影响[J]. 世界科技研究与发展，2010，32(4)：462-465.(WANG Xuebin，PAN Yishan，DU Yazhi. Influence of confining pressures on the rule of acoustic events and energy liberation during rockburst in the surrounding rock of circular tunnel[J]. Word SCI-Tech R&D，2010，32(4)：462-465.(in Chinese))
[7]	冯夏庭，陈炳瑞，明华军，等. 深埋隧洞岩爆孕育规律与机制：即时型岩爆[J]. 岩石力学与工程学报，2012，31(3)：433-444.(FENG Xiating，CHEN Bingrui，MING Huajun，et al. Evolution law and mechanism of rockbursts in deep tunnels：immediate rockburst[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(3)：433-444.(in Chinese))
[8]	马天辉，唐春安，唐烈先，等. 基于微震监测技术的岩爆预测机制研究[J]. 岩石力学与工程学报，2016，35(3)：470-483.(MA Tianhui，TANG Chun?an，TANG Liexian，et al. Mechanism of rock burst forcasting based on micro-seismic monitoring technology[J]. Chinese Journal of Rock Mechanics and Engineering，2016，35(3)：470-483. (in Chinese))
[25]	WANG H J，LIU DAAN，CUI Z D，et al. Investigation of the fracture modes of red sandstone using XFEM and acoustic emissions[J]. Theoretical and Applied Fracture Mechanics，2016，85：283-293.
[9]	张光，吴顺川，张诗淮，等. 砂岩单轴压缩试验P波速度层析成像及声发射特性研究[J]. 岩土力学，2023，44(2)：483-496. (ZHANG Guang，WU Shunchuan，ZHANG Shihuai，et al. P-wave velocity tomography and acoustic emission characteristics of sandstone under uniaxial compression[J]. Rock and Soil Mechanics，2023，44(2)：483-496.(in Chinese))
[10]	刘冬桥，刘赫赫，王炀，等. 钻孔卸压防治岩爆实验及破坏特征研究[J]. 岩石力学与工程学报，2023，42(1)：100-114.(LIU Dongqiao，LIU Hehe，WANG Yang，et al. Experiment study on drilling pressure relief for rockburst prevention and its failure characteristics[J]. Chinese Journal of Rock Mechanics and Engineering，2023，42(1)：100-114.(in Chinese))
[26]	GUTENBERG B，RICHTER C F. Frequency of earthquakes in California[J]. Bulletin of the Seismological Society of America，1944，34(4)：185-188.
[11]	赵奎，李从明，曾鹏，等. 持续高温作用下花岗岩特征应力及声发射特征试验研究[J]. 岩石力学与工程学报，2024，43(7)：1 580-1 592.(ZHAO Kui，LI Congming，ZENG Peng，et al. Experimental study on characteristic stress and acoustic emission characteristics of granite under continued high temperature[J]. Chinese Journal of Rock Mechanics and Engineering，2024，43(7)：1 580- 1 592.(in Chinese))
[27]	吴小平. b值物理机制的再探讨[J]. 西北地震学报，1990，(3)：1-13.(WU Xiaoping. A reapproaching on physical mechanism of b value[J]. Northwestern Seismological Journal，1990，(3)：1-13.(in Chinese))
[12]	贾蓬，钱一锦，王茵，等. 基于声发射信息的热损伤花岗岩单轴压缩破裂机制及破裂前兆[J]. 工程科学学报，2023，45(12)：2 129-2 139.(JIA Peng，QIAN Yijin，WANG Yin，et al. Fracture mechanism and precursors of thermally damaged granite uniaxial compression based on acoustic emission information[J]. Chinese Journal of Engineering，2023，45(12)：2 129-2 139.(in Chinese))
[13]	董陇军，张义涵，孙道元，等. 花岗岩破裂的声发射阶段特征及裂纹不稳定扩展状态识别[J]. 岩石力学与工程学报，2022，41(1)：120-131.(DONG Longjun，ZHANG Yihan，SUN Daoyuan，et al. Stage characteristics of acoustic emission and identification of unstable crack state for granite fractures[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(1)：120-131.(in Chinese))
[28]	MOGI K. Study of the elastic shocks caused by the fracture of heterogeneous materials and the relation to earthquake phenomena[J]. Bulletin of the Earthquake Research Institute，1962，(40)：125-173.
[14]	储超群，吴顺川，曹振生，等. 基于声发射技术的花岗岩破裂特征试验研究[J]. 中南大学学报：自然科学版，2021，52(8)：2 919-2 932. (CHU Chaoqun，WU Shunchuan，CAO Zhensheng，et al. Experimental research on fracture characteristics of granite with acoustic emission technology[J]. Journal of Central South University：Science and Technology，2021，52(8)：2 919-2 932.(in Chinese))
[29]	侯公羽，荆浩勇，梁金平，等. 不同卸荷速率下矩形巷道变形及声发射特性试验研究[J]. 岩土力学，2019，40(9)：3 309-3 318.(HOU Gongyu，JING Haoyong，LIANG Jinping，et al. Experimental study of deformation and acoustic emission characteristics of rectangular roadway under different unloading rates[J]. Rock and Soil Mechanics，2019，40(9)：3 309-3 318.(in Chinese))
[15]	李元辉，刘建坡，赵兴东，等. 岩石破裂过程中的声发射b值及分形特征研究[J]. 岩土力学，2009，30(9)：2 559-2 563.(LI Yuanhui，LIU Jianpo，ZHAO Xingdong，et al. Study on b-value and fractal dimension of acoustic emission during rock failure process[J]. Rock and Soil Mechanics，2009，30(9)：2 559-2 563.(in Chinese))
[30]	MIAO S T，PAN P Z，ZHAO X G，et al. Experimental study on damage and fracture characteristics of Beishan granite subjected to high-temperature treatment with DIC and AE techniques[J]. Rock Mechanics and Rock Engineering，2020，54(1/3)：1-23.
[16]	张国凯，李海波，夏祥，等. 单轴加载条件下花岗岩声发射及波传播特性研究[J]. 岩石力学与工程学报，2017，36(5)：1 133-1 144. (ZHANG Guokai，LI Haibo，XIA Xiang，et al. Experiment study on acoustic emission and wave propagation in granite under uniaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering，2017，36(5)：1 133-1 144.(in Chinese))
[31]	刘冬桥，孙杰，张磊，等. 岩石张拉、剪切裂纹划分方法及其在岩爆前兆中的应用[J]. 中南大学学报：自然科学版，2023，54(3)：1 153-1 167.(LIU Dongqiao，SUN Jie，ZHANG Lei，et al. Division method of tensile and shear crack and its application in sandstone rockburst precursor[J]. Journal of Central South University：Science and Technology，2023，54(3)：1 153-1 167.(in Chinese))
[17]	DU K，LI X F，YANG C Z，et al. Experimental investigations on mechanical performance of rocks under fatigue loads and biaxial confinements[J]. Journal of Central South University，2020，27(10)：2 985-2 998.
[18]	杨永杰，王德超，郭明福，等. 基于三轴压缩声发射试验的岩石损伤特征研究[J]. 岩石力学与工程学报，2014，33(1)：98-104.(YANG Yongjie，WANG Dechao，GUO Mingfu，et al. Study of rock damage characteristics based on acoustic emission tests under triaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(1)：98-104.(in Chinese))
[32]	甘一雄，吴顺川，任义，等. 基于声发射上升时间/振幅与平均频率值的花岗岩劈裂破坏评价指标研究[J]. 岩土力学，2020，41(7)：2 324-2 332.(GAN Yixiong，WU Shunchuan，REN Yi，et al. Evaluation indexes of granite splitting failure based on RA and AF of AE parameters[J]. Rock and Soil Mechanics，2020，41(7)：2 324- 2 332.(in Chinese))
[19]	苗金丽，何满潮，李德建，等. 花岗岩应变岩爆声发射特征及微观断裂机制[J]. 岩石力学与工程学报，2009，28(8)：1 593-1 603. (MIAO Jinli，HE Manchao，LI Dejian，et al. Acoustic emission characteristics of granite under strain rockburst test and its micro-fracture mechanism[J]. Chinese Journal of Rock Mechanics and Engineering，2009，28(8)：1 593-1 603.(in Chinese))
[33]	关庆圆. 钢筋混凝土梁损伤过程的声发射多参数分析及损伤识别[硕士学位论文][D]. 扬州：扬州大学，2023.(GUAN Qingyuan. Acoustic emission multi-parameter analysis and damage identification of reinforced concrete beam damage process[M. S. Thesis][D]. Yangzhou：Yangzhou University，2023.(in Chinese))
[20]	SU G S，GAN W，ZHAI S B，et al. Acoustic emission precursors of static and dynamic instability for coarse-grained hard rock[J]. Journal of Central South University，2020，27(10)：2 883-2 898.
[34]	GRASSBERGER P，PROCACCIA I. Estimation of the Kolmogorov entropy from a chaotic signal[J]. Physical Review A，1983，28(4)：2 591.
[21]	何满潮，赵菲，张昱，等. 瞬时应变型岩爆模拟试验中花岗岩主频特征演化规律分析[J]. 岩土力学，2015，36(1)：1-8.(HE Manchao，ZHAO Fei，ZHANG Yu，et al. Feature evolution of dominant frequency components in acoustic emissions of instantaneous strain-type granitic rockburst simulation tests[J]. Rock and Soil Mechanics，2015，36(1)：1-8.(in Chinese))
[35]	丛宇，冯夏庭，郑颖人，等. 不同应力路径大理岩声发射破坏前兆的试验研究[J]. 岩土工程学报，2016，38(7)：1 193-1 201.(CONG Yu，FENG Xiating，ZHENG Yingren，et al. Experimental study on acoustic emission failure precursors of marble under different stress paths[J]. Chinese Journal of Geotechnical Engineering，2016，38(7)：1 193-1 201.(in Chinese))
[22]	孙飞跃，郭佳奇，刘希亮，等. 真三轴单面卸荷条件下中间主应力对深埋洞室岩爆影响特征[J]. 煤炭学报，2024，49(增1)：220-235. (SUN Feiyue，GUO Jiaqi，LIU Xiliang，et al. Study on the influence of intermediate principal stress on rockburst in deep cavern under true triaxial condition with single face unloading[J]. Journal of China Coal Society，2024，49(Supp.1)：220-235.(in Chinese))
[36]	张艳博，梁鹏，田宝柱，等. 花岗岩灾变声发射信号多参量耦合分析及主破裂前兆特征试验研究[J]. 岩石力学与工程学报，2016，35(11)：2 248-2 258.(ZHANG Yanbo，LIANG Peng，TIAN Baozhu，et al. Multi parameter coupling analysis of acoustic emission signals of granite disaster and the precursor characteristics of the main rupture[J]. Chinese Journal of Rock Mechanics and Engineering，2016，35(11)：2 248-2 258.(in Chinese))
[23]	苏国韶，燕思周，闫召富，等. 真三轴加载条件下岩爆过程的声发射演化特征[J]. 岩土力学，2019，40(5)：1 673-1 682.(SU Guoshao，YAN Sizhou，YAN Zhaofu，et al. Evolution characteristics of acoustic emission in rockburst process under true-triaxial loading conditions[J]. Rock and Soil Mechanics，2019，40(5)：1 673-1 682.(in Chinese))
[24]	曾强. 不同岩爆倾向灰岩声发射参量分析及破裂特征研究[硕士学位论文][D]. 赣州：江西理工大学，2021.(ZENG Qiang. Analysis of acoustic emission parameters of limestone with different rock burst tendencies and research on fracture characteristics[M. S. Thesis][D]. Ganzhou：Jiangxi University of Science and Technology，2021.(in Chinese))
[25]	WANG H J，LIU DAAN，CUI Z D，et al. Investigation of the fracture modes of red sandstone using XFEM and acoustic emissions[J]. Theoretical and Applied Fracture Mechanics，2016，85：283-293.
[26]	GUTENBERG B，RICHTER C F. Frequency of earthquakes in California[J]. Bulletin of the Seismological Society of America，1944，34(4)：185-188.
[27]	吴小平. b值物理机制的再探讨[J]. 西北地震学报，1990，(3)：1-13.(WU Xiaoping. A reapproaching on physical mechanism of b value[J]. Northwestern Seismological Journal，1990，(3)：1-13.(in Chinese))
[28]	MOGI K. Study of the elastic shocks caused by the fracture of heterogeneous materials and the relation to earthquake phenomena[J]. Bulletin of the Earthquake Research Institute，1962，(40)：125-173.
[29]	侯公羽，荆浩勇，梁金平，等. 不同卸荷速率下矩形巷道变形及声发射特性试验研究[J]. 岩土力学，2019，40(9)：3 309-3 318.(HOU Gongyu，JING Haoyong，LIANG Jinping，et al. Experimental study of deformation and acoustic emission characteristics of rectangular roadway under different unloading rates[J]. Rock and Soil Mechanics，2019，40(9)：3 309-3 318.(in Chinese))
[30]	MIAO S T，PAN P Z，ZHAO X G，et al. Experimental study on damage and fracture characteristics of Beishan granite subjected to high-temperature treatment with DIC and AE techniques[J]. Rock Mechanics and Rock Engineering，2020，54(1/3)：1-23.
[31]	刘冬桥，孙杰，张磊，等. 岩石张拉、剪切裂纹划分方法及其在岩爆前兆中的应用[J]. 中南大学学报：自然科学版，2023，54(3)：1 153-1 167.(LIU Dongqiao，SUN Jie，ZHANG Lei，et al. Division method of tensile and shear crack and its application in sandstone rockburst precursor[J]. Journal of Central South University：Science and Technology，2023，54(3)：1 153-1 167.(in Chinese))
[32]	甘一雄，吴顺川，任义，等. 基于声发射上升时间/振幅与平均频率值的花岗岩劈裂破坏评价指标研究[J]. 岩土力学，2020，41(7)：2 324-2 332.(GAN Yixiong，WU Shunchuan，REN Yi，et al. Evaluation indexes of granite splitting failure based on RA and AF of AE parameters[J]. Rock and Soil Mechanics，2020，41(7)：2 324- 2 332.(in Chinese))
[33]	关庆圆. 钢筋混凝土梁损伤过程的声发射多参数分析及损伤识别[硕士学位论文][D]. 扬州：扬州大学，2023.(GUAN Qingyuan. Acoustic emission multi-parameter analysis and damage identification of reinforced concrete beam damage process[M. S. Thesis][D]. Yangzhou：Yangzhou University，2023.(in Chinese))
[34]	GRASSBERGER P，PROCACCIA I. Estimation of the Kolmogorov entropy from a chaotic signal[J]. Physical Review A，1983，28(4)：2 591.
[35]	丛宇，冯夏庭，郑颖人，等. 不同应力路径大理岩声发射破坏前兆的试验研究[J]. 岩土工程学报，2016，38(7)：1 193-1 201.(CONG Yu，FENG Xiating，ZHENG Yingren，et al. Experimental study on acoustic emission failure precursors of marble under different stress paths[J]. Chinese Journal of Geotechnical Engineering，2016，38(7)：1 193-1 201.(in Chinese))
[36]	张艳博，梁鹏，田宝柱，等. 花岗岩灾变声发射信号多参量耦合分析及主破裂前兆特征试验研究[J]. 岩石力学与工程学报，2016，35(11)：2 248-2 258.(ZHANG Yanbo，LIANG Peng，TIAN Baozhu，et al. Multi parameter coupling analysis of acoustic emission signals of granite disaster and the precursor characteristics of the main rupture[J]. Chinese Journal of Rock Mechanics and Engineering，2016，35(11)：2 248-2 258.(in Chinese))