|
|
|
| STUDY OF CHARACTERISTICS OF b VALUE FOR MICROSEISMIC EVENTS IN HIGH ROCK SLOPE |
| XU Nuwen1，2，DAI Feng1，ZHOU Zhong3，SHA Chun3，TANG Chun?an4 |
| (1. State Key Laboratory of Hydraulics and Mountain River Engineering，Sichuan University，Chengdu，Sichuan 610065，China；2. School of Civil and Hydraulic Engineering，Shandong University，Jinan，Shandong 250061，China；3. HydroChina Chengdu Engineering Corporation，Chengdu，Sichuan 610072，China；4. School of Civil Engineering，Dalian University of Technology，Dalian，Liaoning 116024，China) |
|
|
|
|
Abstract The magnitude-frequency relation(b value) of microseismic events recorded at the left bank slope of Jinping first stage hydropower station was analyzed. In order to in-depth investigate the slope stability and resolve the complex surface conditions of highly fractured rock mass，a microseismic monitoring system was implemented at the rock slope in June 2009 based on common monitoring instrument including multipoint extensometer and graphite rod convergence gauge. Seismic source parameters such as magnitude，location and time were captured during the monitoring period. The variation of b value was thus determined with time and excavation-induced microcrackings were identified and delineated after analyzing the monitoring data recorded from June 2009 and to 2011. Results show that rock mass damage is closely related with b value. The b value of microseismic events at the dam spandrel equals 0.87，showing the microseismicity plays little effect on the rock slope stability. Meanwhile，the little increase of b value(from 0.49 to 0.65) at the unknown geological structure indicated the hazard probability of rock mass failure inside the unknown geological structure of left slope decreased. Results can provide references for predicting rock mass instability and improving monitoring accuracy in similar rock slopes.
|
|
Received: 26 April 2013
|
|
|
|
| [1] LABUZ J F，BIOLZI L. Experiment with rock：remarks on strength and stability issues[J]. International Journal of Rock Mechanics and Mining Sciences，2007，44(4)：525–537.
[2] LEI X L，MASUDA K，NISHIZAWA O，et al. Detailed analysis of acoustic emission activity during catastrophic fracture of faults in rock[J]. Journal of Structural Geology，2004，26(2)：247–258.
[3] 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)：2 559–2 564.(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)：2 559–2 564.(in Chinese))
[4] 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))
[5] 高 峰，李建军，李肖音，等. 岩石声发射特征的分形分析[J]. 武汉理工大学学报，2005，27(7)：67–69.(GAO Feng，LI Jianjun，LI Xiaoyin，et al. Fractal analysis of the characteristics of acoustic emission of rock[J]. Journal of Wuhan University of Technology，2005，27(7)：67–69.(in Chinese))
[6] 董毓利，谢和平，赵 鹏. 混凝土受压全过程声发射b值与分形维值的研究[J]. 实验力学，1996，11(3)：273–276.(DONG Yuli，XIE Heping，ZHAO Peng. Study on b value and fractal dimension Df of concrete under complete process compression[J]. Journal of Experimental Mechanics，1996，11(3)：273–276.(in Chinese))
[7] 唐礼忠，汪令辉，张 君，等. 大规模开采矿山地震视应力和变形与区域性危险地震预测[J]. 岩石力学与工程学报，2011，30(6)： 1 168–1 178.(TANG Lizhong，WANG Linghui，ZHANG Jun，et al. Seismic apparent stress and deformation in a deep mine under large-scale mining and area hazardous seismic prediction[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(6)：1 168–1 178.(in Chinese))
[8] 李庶林，尹贤刚，郑文达，等. 凡口铅锌矿多通道微震监测系统及其应用研究[J]. 岩石力学与工程学报，2005，24(12)：2 048–2 053. (LI Shulin，YIN Xiangang，ZHENG Wenda，et al. Research of multi- channel microseismic monitoring system and its application to Fankou lead-zinc mine[J]. Chinese Journal of Rock Mechanics and Engineering，2005，24(12)：2 048–2 053.(in Chinese))
[9] 姜福兴，叶根喜，王存文，等. 高精度微震监测技术在煤矿突水监测中的应用[J]. 岩石力学与工程学报，2008，27(9)：1 932–1 938. (JIANG Fuxing，YE Genxi，WANG Cunwen，et al. Application of high-precision microseismic monitoring technique to water inrush monitoring in coal mine[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(9)：1 932–1 938.(in Chinese))
[10] 李 铁，纪洪广. 矿井不明水体突出过程的微震辨识技术[J]. 岩石力学与工程学报，2010，29(1)：134–139.(LI Tie，JI Hongguang. Identification of water inrush process of unknown water body using microseismic monitoring technique[J]. Chinese Journal of Rock Mechanics and Engineering，2010，29(1)：134–139.(in Chinese))
[11] XU N W，TANG C A，LI L C，et al. Microseismic monitoring and stability analysis of the left bank slope in Jinping first stage hydropower station in southwestern China[J]. International Journal of Rock Mechanics and Mining Sciences，2011，48(6)：950–963.
[12] 徐奴文，唐春安，沙 椿，等. 锦屏一级水电站左岸边坡微震监测系统及其应用研究[J]. 岩石力学与工程学报，2010，29(5)：915–925.(XU Nuwen，TANG Chun?an，SHA Chun，et al. Microseismic monitoring system establishment and its engineering applications to left bank slope of Jinping I hydropower station[J]. Chinese Journal of Rock Mechanics and Engineering，2010，29(5)：915–925.(in Chinese))
[13] 徐奴文，唐春安，周 钟，等. 岩石边坡潜在失稳区域微震识别方法[J]. 岩石力学与工程学报，2011，30(5)：893–900.(XU Nuwen，TANG Chun?an，ZHOU Zhong，et al. Identification of potential failure regions using microseismic monitoring technique[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(5)：893–900.(in Chinese))
[14] TANG C A，WANG J M，ZHANG J J. Preliminary engineering appliction of microseismic monitoring technique to rockburst prediction in tunneling of Jinping II project[J]. Journal of Rock Mechanics and Geotechnical Engineering，2011，2(3)：193–208.
[15] 陈炳瑞，冯夏庭，曾雄辉，等. 深埋隧洞TBM掘进微震实时监测与特征分析[J]. 岩石力学与工程学报，2011，30(2)：275–283. (CHEN Bingrui，FENG Xiating，ZENG Xionghui，et al. Real-time microseismic monitoring and its characteristic analysis during TBM tunneling in deep-buried tunnel[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(2)：275–283.(in Chinese))
[16] 张伯虎，邓建辉，高明忠，等. 基于微震监测的水电站地下厂房安全性评价研究[J]. 岩石力学与工程学报，2012，31(5)：937–944. (ZHANG Bohu，DENG Jianhui，GAO Mingzhong，et al. Safety evaluation research based on microseismic monitoring in underground powerhouse of hydropower station[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(5)：937–944.(in Chinese))
[17] GUTENBERG B，RICHTER C F. Frequency of earthquakes in California[J]. Bulletin of the Seismological Society of America，1944，34(4)：185–188.
[18] 李全林，于 涛，郝柏林，等. 地震频度——震级关系的时空扫描[M]. 北京：地震出版社，1979：109.(LI Quanlin，YU Tao，HAO Bolin，et al. Tempo-spatial scanning of earthquake frequency- magnitude relation[M]. Beijing：Seismological Press，1979：109.(in Chinese))
[19] GIBOWICZ S J，KIJKO A. An introduction to mining seismology[M]. New York：Academic Press，1994：396.
[20] LEGGE N B，SPOTTISWOODE S M. Fracturing and microseismicity ahead of a deep gold mine stope in the pre-remnant stages of mining[C]// Proceedings of the 6th International Congress on Rock Mechanics. Montreal：[s.n.]，1987：1 071–1 078.
[21] HUDYMA M R，MILNE D，GRANT D R. Geomechanics of sill pillar mining in rockburst prone conditions. Final report：sill pillar monitoring using conventional methods[R]. [S.l.] ：Mining Research Directorate，1995：104.
[22] HUDYMA M R. Analysis and interpretation of clusters of seismic events in mines[Ph. D. Thesis][D]. Perth，Australia：University of Western Australia，2008.
[23] LEI X L，KUSUNOSE K，NISHIZAWA O，et al. Quasi-static fault growth and cracking in homogeneous brittle rock under triaxial compression using acoustic emission monitoring[J]. Journal of Geophysical Research，2000，105(B3)：6 127–6 139.
[24] WANG C L，WU A X，LIU X H，et al. Study on fractal characteristics of b value with microseismic activity in deep mining[J]. Procedia Earth and Planetary Science，2009，1(1)：592–597. |
|
|
|
2014, Vol. 33 
