|
|
|
| Acoustic emission characteristics of rock bridge test under different stress paths |
| CHEN Guoqing，ZHAO Cong，LIU Hui，HUANG Runqiu |
(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection，Chengdu University of Technology，
Chengdu，Sichuan 610059，China) |
|
|
|
|
Abstract The failure of rock bridge in rock slopes is an important factor for the instability of a slope. The triaxial loading，triaxial loading-unloading and triaxial unloading tests of different length of rock bridges were carried out. Acoustic emission(AE) characteristics of rock bridge during failure process under different stress paths was described，and the influence of confining pressure and rock bridge length on the AE characteristics was analyzed. The results showed that AE events are low during the compression and elastic deformation phase. AE events increased significantly during the plastic phase，and AE counts，the accumulated energy and amplitude reached their peak during failure phase. Significant changes in AE characteristics can be used as early warning for failure of rock sample， the variation of amplitude is more sensitive than other AE indicators. Therefore the monitoring of the amplitude is more effective for the failure warning. In this experiment the rock bridge is not immediately dropped to the residual strength after the peak strength，but two stress drop occurred after peak stress，each sudden drop of stress corresponds to the AE signal peaks. The phenomenon of“quiet period”or“post-peak rebound”occurred in the two stress drop，and AE characteristics of the“post-peak rebound”and“quiet period”is similar to the plastic phase. However，its amplitude，count rate and the accumulated energy are greater than plastic deformation stage which indicates the rock crack is still in a relatively rapid rate expansion，and resulting in the failure of rock bridge. Accumulated energy from the large to small are triaxial loading-unloading，triaxial unloading and triaxial loading under different stress paths. With the increase of length of rock bridges and confining pressure AE count rate peak and cumulative energy increased，and meaning more severe failure of rock bridge.
|
|
|
|
|
|
[1] 秦四清，李造鼎，张倬元，等. 岩石声发射技术概论[M]. 成都：西南交通大学出版社，1993：16–18.(QIN Siqing，LI Zaoding，ZHANG Zhuoyuan，et al. An introduction to acoustic emission techniques in rocks[M]. Chengdu：Southwest Jiaotong University Press，1993：16–18.(in Chinese))
[2] MANSUROV V A. Acoustic emission from failing rock behavior[J]. Rock Mechanics and Rock Engineering，1994，27(3)：173–182.
[3] HOLCOMB D J，COSTIN L S. Detecting damage surfaces in brittle materials using acoustic emissions[J]. Transactions of the ASME，1986，53(2)：536–544.
[4] SHIOTANI T，OHTSU M，IKEDA K. Detection and evaluation of AE waves due to rock deformation[J]. Construction and Building Materials，2001，15(5/6)：235–246.
[5] CAI M，MORIOKA H，KAISER P K，et al. Back-analysis of rock mass strength parameters using AE monitoring data[J]. International Journal of Rock Mechanics and Mining Sciences，2007，44(4)：538–549.
[6] SHKURATNIK V L，FILIMONOV L，KUCHURIN S V. Regularities of acoustic emission in coal samples under triaxial compression[J]. Journal of Mining Science，2005，41(1)：44–52.
[7] CHANG S H，LEE C I. Estimation of cracking and damage mechanisms in rock under triaxial compression by moment tensor analysis of acoustic emission[J]. International Journal of Rock Mechanics and Mining Sciences，2004，41(3)：1 069–1 086.
[8] 李庶林，尹贤刚，王泳嘉，等. 单轴受压岩石破坏全过程声发射特征研究[J]. 岩石力学与工程学报，2004，23(15)：2 499–2 503.(LI Shulin，YIN Xiangang，WANG Yongjia，et al. Studies of acoustic emission characteristics of uniaxial compressive rock failure[J]. Chinese Journal of Rock Mechanics and Engineering，2004，23(15)：2 499–2 503.(in Chinese))
[9] 余贤斌，谢 强，李心一，等. 直接拉伸、劈裂及单轴压缩试验下岩石的声发射特性[J]. 岩石力学与工程学报，2007，26(1)：137–142.(YU Xianbin，XIE Qiang，LI Xinyi，et al. Acoustic emission of rocks under direct tension，Brazilian and uniaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering，2007，26(1)：137–142.(in Chinese))
[10] 张晖辉，颜玉定，余怀忠，等. 循环载荷下大试件岩石破坏声发射实验——岩石破坏前兆的研究[J]. 岩石力学与工程学报，2004，23(21)：3 621–3 628.(ZHANG Huihui，YAN Yuding，YU Huaizhong，et al. Acoustic emission experimental research on large-scaled rock failure under cycling load-fracture precursor of rock[J]. Chinese Journal of Rock Mechanics and Engineering，2004，23(21)：3 621– 3 628.(in Chinese))
[11] 吴 刚，赵震洋. 不同应力状态下岩石类材料破坏的声发射特性[J]. 岩土工程学报，1998，20(2)：82–85.(WU Gang，ZHAO Zhenyang. Acoustic emission character of rock materials failure during various stress states[J]. Chinese Journal of Geotechnical Engineering，1998，20(2)：82–85.(in Chinese))
[12] 张 茹，谢和平，刘建锋，等. 单轴多级加载岩石破坏声发射特性试验研究[J]. 岩石力学与工程学报，2006，25(12)：2 584–2 588. (ZHANG Ru，XIE Heping，LIU Jianfeng，et al. Experimental study on acoustic emission characteristics of rock failure under uniaxial multilevel loadings[J]. Chinese Journal of Rock Mechanics and Engineering，2006，25(12)：2 584–2 588.(in Chinese))
[13] 蒋 宇，葛修润，任建喜. 岩石疲劳破坏过程中的变形规律及声发射特性[J]. 岩石力学与工程学报，2004，23(11)：1 810–1 814. (JIANG Yu，GE Xiurun，REN Jianxi. Deformation rules and acoustic emission characteristics of rocks in process of fatigue failure[J]. Chinese Journal of Rock Mechanics and Engineering，2004，23(11)：1 810–1 814.(in Chinese))
[14] 苏承东，高保彬，南 华，等. 不同应力路径下煤样变形破坏过程声发射特征的试验研究[J]. 岩石力学与工程学报，2009，28(4)：757–766.(SU Chengdong，GAO Baobin，NAN Hua，et al. Experimental study of acoustic emission characteristics during deformation and failure processes of coal samples under stress paths[J]. Chinese Journal of Rock Mechanics and Engineering，2009，28(4)：757–766.(in Chinese))
[15] 张黎明，王在泉，石 磊，等. 不同应力路径下大理岩破坏过程的声发射特性[J]. 岩石力学与工程学报，2012，31(6)：1 230–1 236. (ZHANG Liming，WANG Zaiquan，SHI Lei，et al. Acoustic emission characteristics of marble during failure process under different stress paths[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(6)：1 230–1 236.(in Chinese))
[16] 丛 宇，王在泉，郑颖人，等. 卸围压路径下大理岩破坏过程的声发射特性试验研究[J]. 西南交通大学学报，2014，49(1)：97–104.(CONG Yu，WANG Zaiquan，ZHENG Yingren，et al. Experimental study on acoustic emission features of marbles during unloading failure process[J]. Journal of Southwest Jiaotong University，2014，49(1)：97–104.(in Cinese))
[17] CHEN G Q，ZHANG Y，HUANG R Q，et al. Failure Mechanism of Rock Bridge Based on Acoustic Emission Technique[J]. Journal of Sensors，2015，Article ID 964730.
[18] 范 雷，周火明，熊诗湖. 现场岩体直剪试验声发射特征与其破坏机制[J]. 长江科学院报，2012，29(8)：29–32.(FAN Lei，ZHOU Huoming，XIONG Shihu. Acoustic emission characteristics and failure mechanism of rock mass in field shear test[J]. Journal of Yangtze River Scientific Research Institute，2012，29(8)：29–32.(in Chinese))
[19] 周 辉，孟凡震，张传庆，等. 结构面剪切过程中声发射特性的试验研究[J]. 岩石力学与工程学报，2015，34(增1)：2 827–2 836. (ZHOU Hui，MENG Fanzhen，ZHANG Chuanqing，et al. Experimental study of acoustic emission characteristic of discontinuity under shearing condition[J]. Chinese Journal of Rock Mechanics and Engineering，2015，34(Supp.1)：2 827–2 836.(in Chinese)) |
|
|
|
2016, Vol. 35 
