Analysis of dynamic fragmentation characteristics of rock avalanche with tectonic joints
-
摘要: 近年来西南地区崩塌灾害频发,严重影响区域生态环境和人类活动。为明确崩塌体运动过程中的破碎特征,基于对纳雍县鬃岭崩塌的野外地质勘察,使用离散元颗粒流方法模拟了鬃岭崩塌在破坏及堆积阶段的动力破碎过程,并对崩塌体中破碎体的最大弗雷特直径(Feret’s diameter)分布特征进行统计分析。结果表明:1. 重力作用下鬃岭崩塌内部构造节理迅速贯通,将崩塌体分割为大量破碎块体,最终沿顺倾节理面滑下。2. 在崩塌前期破坏及后续堆积过程中均存在明显的破碎现象,具体表现为初始破坏时的大范围解体与后续堆积过程中的摩擦拉裂破碎。3. 采用双参数Weibull分布模型及分形几何理论拟合了不同时刻破碎体粒径分布曲线,结果显示崩塌体在堆积阶段(t = 21.7~72.4 s)的破碎程度弱于前期破坏阶段(t = 0~21.7 s)的破碎程度,破碎体的分形维数及细粒径破碎体的占比在整个运动过程中不断增大,再次论证了崩塌体破坏及堆积全过程中的破碎解体现象。研究结果为揭示鬃岭崩塌的动力破碎机理提供了理论依据,为西南山区崩塌灾害的防治提供了科学指导。Abstract: In recent years, rock avalanche disasters have been occurring frequently in southwest China, which seriously affect the regional ecological environment and human activities. To understand the fragmentation characteristics of the avalanche masses during their movement, this study is based on the field investigation of the rock avalanche in Zongling Town, Nayong County. The dynamic fragmentation process of the rock avalanche during the failure and accumulation stages was simulated using the particle discrete element method. Additionally, the distribution characteristics of the maximum Feret's diameter of the fragments within the rock avalanche mass were statistically analyzed. The results show that: 1. Under the effect of gravity, the internal structural joints of the rock avalanche rapidly interconnected, dividing the avalanche mass into numerous fragmented blocks that eventually slid along the down-dip joint surfaces. 2. The collapse exhibited significant fragmentation phenomena in the entire movement process, with extensive disintegration during the initial failure and friction-induced tearing and cracking fragmentation during the accumulation stage. 3. The feret's diameter distribution curves of the fragments at different time intervals were fitted using Weibull two-parameter distribution model and fractal geometry theory. The results showed that the fragmentation degree of the avalanche during the accumulation stage (t = 21.7 to 72.4 s) was weaker than that during the initial failure stage (t = 0 to 21.7 s). The fractal dimension of the fragments and the proportion of fine-grained fragments continuously increased throughout the entire movement process, once again confirming the fragmentation and disintegration phenomena during the entire process of failure and accumulation. The research findings provide a theoretical basis for revealing the dynamic fragmentation mechanism of the Zongling rock avalanche, and provide scientific guidance for the prevention and control of rock avalanche disasters in the mountainous areas of Southwest China.
-
Key words:
- rock avalanche /
- dynamic fragmentation /
- tectonic joints /
- Feret's diameter /
- discrete element method
-
图 1 纳雍县鬃岭崩塌
Figure 1. Aerial view of the Zongling rock avalanche: (a) satellite photograph of the rock avalanche in Zongling Town, Nayong County; (b) stratum lithology in the Zongling avalanche area; (c) photo of the avalanches from the panoramic view[19]
表 1 合成岩石试样(SRMS)微观参数
Table 1. Micromechanical parameters of synthetic rock mass specimen(SMRS)
关键参数名称 参数值 颗粒密度 ρ/(kg/m3) 2 200 颗粒粒径R/(m) 0.002-0.003 颗粒有效模量emod/(N/m2) 7e9 刚度比kratio 1.5 胶结有效模量pb_emod/(N/m2) 1.21e10 胶结刚度比pb_kratio 1.5 胶结抗拉强度pb_ten/(N/m2) 8.1e8 胶结粘聚力pb_coh/(N/m2) 4.6e8 胶结内摩擦角pb_fa/(degree) 39.8 -
[1] 曲雪妍,李媛,杨旭东,等. 中国地质灾害总体特征与形势分析[J]. 中国地质灾害与防治学报,2016,27(4):109 − 113. [QU Xueyan,LI Yuan,YANG Xudong,et al. The general characteristics and situation analysis of geo-hazards in China[J]. The Chinese Journal of Geological Hazard and Control,2016,27(4):109 − 113. (in Chinese with English abstract) doi: 10.16031/j.cnki.issn.1003-8035.2016.04.19 QU Xueyan, LI Yuan, YANG Xudong, et al . The general characteristics and situation analysis of geo-hazards in China[J]. The Chinese Journal of Geological Hazard and Control,2016 ,27 (4 ):109 −113 . (in Chinese with English abstract) doi: 10.16031/j.cnki.issn.1003-8035.2016.04.19[2] 丁俊,魏伦武,赖绍民,等. 我国西南地区城市地质灾害与防治对策[J]. 中国地质灾害与防治学报,2004,15(增刊1):119 − 122. [DING Jun,WEI Lunwu,LAI Shaomin,et al. Urban geological hazard and countermeasures of control in Southwest of China[J]. The Chinese Journal of Geological Hazard and Control,2004,15(Sup 1):119 − 122. (in Chinese with English abstract)DING Jun, WEI Lunwu, LAI Shaomin, et al. Urban geological hazard and countermeasures of control in Southwest of China[J]. The Chinese Journal of Geological Hazard and Control, 2004, 15(Sup 1): 119 − 122. (in Chinese with English abstract) [3] 陈鹏宇. 岩质高边坡坡体结构特征分析与稳定性研究——以焦作市龙寺矿山岩质高边坡为例[D]. 武汉:中国地质大学,2015. [CHEN Pengyu. Structural characteristics analysis and stability study of high rock slope:A case study of Longsi Mine in Jiaozuo City[D]. Wuhan:China University of Geosciences,2015. (in Chinese with English abstract)CHEN Pengyu. Structural characteristics analysis and stability study of high rock slope: A case study of Longsi Mine in Jiaozuo City[D]. Wuhan: China University of Geosciences, 2015. (in Chinese with English abstract) [4] 贺续文,刘忠,廖彪,等. 基于离散元法的节理岩体边坡稳定性分析[J]. 岩土力学,2011,32(7):2199 − 2204. [HE Xuwen,LIU Zhong,LIAO Biao,et al. Stability analysis of jointed rock slopes based on discrete element method[J]. Rock and Soil Mechanics,2011,32(7):2199 − 2204. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-7598.2011.07.046 HE Xuwen, LIU Zhong, LIAO Biao, et al . Stability analysis of jointed rock slopes based on discrete element method[J]. Rock and Soil Mechanics,2011 ,32 (7 ):2199 −2204 . (in Chinese with English abstract) doi: 10.3969/j.issn.1000-7598.2011.07.046[5] HE L,AN X M,MA G W,et al. Development of three-dimensional numerical manifold method for jointed rock slope stability analysis[J]. International Journal of Rock Mechanics and Mining Sciences,2013,64:22 − 35. doi: 10.1016/j.ijrmms.2013.08.015 [6] AN Xinmei,NING Youjun,MA Guowei,et al. Modeling progressive failures in rock slopes with non-persistent joints using the numerical manifold method[J]. International Journal for Numerical and Analytical Methods in Geomechanics,2014,38(7):679 − 701. doi: 10.1002/nag.2226 [7] 李连崇,唐春安,邢军,等. 节理岩质边坡变形破坏的RFPA模拟分析[J]. 东北大学学报,2006,27(5):559 − 562. [LI Lianchong,TANG Chunan,XING Jun,,et al. Numerical simulation and analysis of deformation and failure of jointed rock slopes by RFPA-slope[J]. Journal of Northeastern University (Natural Science),2006,27(5):559-562. (in Chinese with English abstract)LI Lianchong, TANG Chunan, XING Jun, , et al. Numerical simulation and analysis of deformation and failure of jointed rock slopes by RFPA-slope[J]. Journal of Northeastern University (Natural Science), 2006, 27(5): 559-562. (in Chinese with English abstract) [8] 张秀丽. 断续节理岩体破坏过程的数值分析方法研究[D]. 武汉:中国科学院研究生院(武汉岩土力学研究所),2007. [ZHANG Xiuli. Study on numerical analysis method of failure process of discontinuous jointed rock mass[D]. Wuhan:Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,2007. (in Chinese with English abstract)ZHANG Xiuli. Study on numerical analysis method of failure process of discontinuous jointed rock mass[D]. Wuhan: Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, 2007. (in Chinese with English abstract) [9] 王博. 破碎岩石边坡动力稳定性及抗震加固研究[D]. 重庆:重庆交通大学,2020. [WANG Bo. Study on dynamic stability and seismic reinforcement of broken rock slope[D]. Chongqing:Chongqing Jiaotong University,2020. (in Chinese with English abstract)WANG Bo. Study on dynamic stability and seismic reinforcement of broken rock slope[D]. Chongqing: Chongqing Jiaotong University, 2020. (in Chinese with English abstract) [10] LOCAT P,COUTURE R,LEROUEIL S,et al. Fragmentation energy in rock avalanches[J]. Canadian Geotechnical Journal,2006,43(8):830 − 851. doi: 10.1139/t06-045 [11] CROSTA G B,FRATTINI P,FUSI N. Fragmentation in the val pola rock avalanche,Italian Alps[J]. Journal of Geophysical Research,2007,112(F1):F01006. [12] PERINOTTO H,SCHNEIDER J L,BACHÈLERY P,et al. The extreme mobility of debris avalanches:A new model of transport mechanism[J]. Journal of Geophysical Research:Solid Earth,2015,120(12):8110 − 8119. doi: 10.1002/2015JB011994 [13] WANG Yufeng,CHENG Qiangong,ZHU Qi. Surface microscopic examination of quartz grains from rock avalanche basal facies[J]. Canadian Geotechnical Journal,2015,52(2):167 − 181. doi: 10.1139/cgj-2013-0284 [14] LUO Junyao,XU Zemin,REN Zhe,et al. Rock avalanche-debris geometry and implications for rock-avalanche genesis[J]. Geomorphology,2019,334:60 − 75. doi: 10.1016/j.geomorph.2019.02.029 [15] CAGNOLI B,ROMANO G P. Effect of grain size on mobility of dry granular flows of angular rock fragments:An experimental determination[J]. Journal of Volcanology and Geothermal Research,2010,193(1/2):18 − 24. [16] GAO Ge,MEGUID M A,CHOUINARD L E,et al. Insights into the transport and fragmentation characteristics of earthquake-induced rock avalanche:numerical study[J]. International Journal of Geomechanics,2020,20(9):■ − ■. [17] DUNNING S A. The grain size distribution of rock- avalanche deposits in valley-confined settings[J]. Italian Journal of Engineering Geology and Environment,2006(1):117 − 121. [18] 常文斌,王平,于一帆,等. 颗粒离散元模拟边坡动力响应的研究进展[J]. 水利与建筑工程学报,2021,19(2):48 − 53. [CHANG Wenbin,WANG Ping,YU Yifan,et al. Research progress of the slope dynamic response simulation by particle discrete elements method[J]. Journal of Water Resources and Architectural Engineering,2021,19(2):48 − 53. (in Chinese with English abstract) doi: 10.3969/j.issn.1672-1144.2021.02.009 CHANG Wenbin, WANG Ping, YU Yifan, et al . Research progress of the slope dynamic response simulation by particle discrete elements method[J]. Journal of Water Resources and Architectural Engineering,2021 ,19 (2 ):48 −53 . (in Chinese with English abstract) doi: 10.3969/j.issn.1672-1144.2021.02.009[19] WANG Jing,WANG Chao,XIE Chou,et al. Monitoring of large-scale landslides in Zongling,Guizhou,China,with improved distributed scatterer interferometric SAR time series methods[J]. Landslides,2020,17(8):1777 − 1795. doi: 10.1007/s10346-020-01407-5 [20] CUNDALL P A. A computer model for simulating progressive,large scale movement in blocky rock systems[J]. Symp. ISRM,Nancy,France,Proc,1971,2. [21] GAO Ge,MEGUID M A,CHOUINARD L E,et al. Dynamic disintegration processes accompanying transport of an earthquake-induced landslide[J]. Landslides,2021,18(3):909 − 933. doi: 10.1007/s10346-020-01508-1 [22] CHEONG Y S,SALMAN A D,HOUNSLOW M J. Effect of impact angle and velocity on the fragment size distribution of glass spheres[J]. Powder Technology,2003,138(2/3):189 − 200. [23] PALUSZNY A,TANG Xuhai,NEJATI M,et al. A direct fragmentation method with Weibull function distribution of sizes based on finite- and discrete element simulations[J]. International Journal of Solids and Structures,2016,80:38 − 51. doi: 10.1016/j.ijsolstr.2015.10.019 [24] CHEONG Y S,REYNOLDS G K,SALMAN A D,et al. Modelling fragment size distribution using two-parameter Weibull equation[J]. International Journal of Mineral Processing,2004,74:S227 − S237. doi: 10.1016/j.minpro.2004.07.012 [25] SHEN Weigang,ZHAO Tao,CROSTA G B,et al. Analysis of impact-induced rock fragmentation using a discrete element approach[J]. International Journal of Rock Mechanics and Mining Sciences,2017,98:33 − 38. doi: 10.1016/j.ijrmms.2017.07.014 [26] 王有鹏,李德文,王锦鹏. 金沙江巧家段冲积物动态图像法粒度特征研究[J]. 地质论评,2019,65(2):503 − 513. [WANG Youpeng,LI Dewen,WANG Jinpeng. Analysis on grain size of alluvial sediments in the Qiaojia segment,Upper Yangtze River,based on dynamic image method[J]. Geological Review,2019,65(2):503 − 513. (in Chinese with English abstract) doi: 10.16509/j.georeview.2019.02.019 WANG Youpeng, LI Dewen, WANG Jinpeng . Analysis on grain size of alluvial sediments in the Qiaojia segment, Upper Yangtze River, based on dynamic image method[J]. Geological Review,2019 ,65 (2 ):503 −513 . (in Chinese with English abstract) doi: 10.16509/j.georeview.2019.02.019[27] 陈泽琦,范伟军,郭斌,等. 基于形态重建和反向跟踪的粗集料级配视觉检测[J]. 计量学报,2021,42(6):710 − 717. [CHEN Zeqi,FAN Weijun,GUO Bin,et al. A visual detection method for particle size of moving coarse aggregate based on morphological reconstruction and reverse tracking[J]. Acta Metrologica Sinica,2021,42(6):710 − 717. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-1158.2021.06.04 CHEN Zeqi, FAN Weijun, GUO Bin, et al . A visual detection method for particle size of moving coarse aggregate based on morphological reconstruction and reverse tracking[J]. Acta Metrologica Sinica,2021 ,42 (6 ):710 −717 . (in Chinese with English abstract) doi: 10.3969/j.issn.1000-1158.2021.06.04[28] MIN Wang. Analysis on bubble sort algorithm optimization[C]//2010 International Forum on Information Technology and Applications. July 16 − 18,2010,Kunming,China. IEEE,2010:208 − 211. [29] 美)Clifford A. Shaffer. 数据结构与算法分析:C++版[M]. 张铭,刘晓丹等译. 北京:电子工业出版社,2010. [CLIFFORD A practical introduction to data structures and algorithm analysis[M]. Beijing:Publishing House of Electronics Industry,2010. (in Chinese with English abstract)CLIFFORD A practical introduction to data structures and algorithm analysis[M]. Beijing: Publishing House of Electronics Industry, 2010. (in Chinese with English abstract) [30] ZHANG Jian,JIN Rui. An improved bubble sort method - marking bubble sort[C]//Xu Z,Parizi RM,Loyola-González O,et al. The International Conference on Cyber Security Intelligence and Analytics. Cham:Springer,2021:862 − 868. [31] WALTON W H. Feret‘s statistical diameter as a measure of particle size[J]. Nature,1948,162(4113):329 − 330. [32] EPSTEIN B. The mathematical description of certain breakage mechanisms leading to the logarithmico-normal distribution[J]. Journal of the Franklin Institute,1947,244(6):471 − 477. doi: 10.1016/0016-0032(47)90465-1 [33] ROSIN P. Laws governing the fineness of powdered coal[J]. Journal of Institute of Fuel,1933,7:29 − 36. [34] MOTT N F,LINFOOT E H. A theory of fragmentation[M]// Fragmentation of Rings and Shells. Berlin,Heidelberg:Springer,2006:207 − 225. [35] PALUSZNY A,TANG X H,ZIMMERMAN R W. Fracture and impulse based finite-discrete element modeling of fragmentation[J]. Computational Mechanics,2013,52(5):1071 − 1084. doi: 10.1007/s00466-013-0864-5 [36] MCSAVENEY M J. Recent rockfalls and rock avalanches in mount cook National Park,new zealand[M]//Reviews in Engineering Geology. 2002,15::Geological Society of America,2002:35 − 70. [37] MA Gang,ZHOU Wei,REGUEIRO R A,et al. Modeling the fragmentation of rock grains using computed tomography and combined FDEM[J]. Powder Technology,2017,308:388 − 397. doi: 10.1016/j.powtec.2016.11.046 [38] SALMAN A D,HOUNSLOW M J,VERBA A. Particle fragmentation in dilute phase pneumatic conveying[J]. Powder Technology,2002,126(2):109 − 115. doi: 10.1016/S0032-5910(02)00048-7 [39] WEIBULL W. A statistical distribution function of wide applicability[J]. Journal of Applied Mechanics,1951,18(3):293 − 297. doi: 10.1115/1.4010337 [40] CARMONA H A,WITTEL F K,KUN F,et al. Fragmentation processes in impact of spheres[J]. Physical Review E,Statistical,Nonlinear,and Soft Matter Physics,2008,77(5 Pt 1):051302. [41] TURCOTTE D L. Fractals and fragmentation[J]. Journal of Geophysical Research,1986,91(B2):1921. doi: 10.1029/JB091iB02p01921 [42] IGATHINATHANE C,MELIN S,SOKHANSANJ S,et al. Machine vision based particle size and size distribution determination of airborne dust particles of wood and bark pellets[J]. Powder Technology,2009,196(2):202 − 212. doi: 10.1016/j.powtec.2009.07.024 [43] 王玉峰,程谦恭,朱圻. 汶川地震触发高速远程滑坡-碎屑流堆积反粒序特征及机制分析[J]. 岩石力学与工程学报,2012,31(6):1089 − 1106. [WANG Yufeng,CHENG Qiangong,ZHU Qi. Inverse grading analysis of deposit from rock avalanches triggered by Wenchuan earthquake[J]. Chinese Journal of Rock Mechanics and Engineering,2012,31(6):1089 − 1106. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-6915.2012.06.002 WANG Yufeng, CHENG Qiangong, ZHU Qi . Inverse grading analysis of deposit from rock avalanches triggered by Wenchuan earthquake[J]. Chinese Journal of Rock Mechanics and Engineering,2012 ,31 (6 ):1089 −1106 . (in Chinese with English abstract) doi: 10.3969/j.issn.1000-6915.2012.06.002 -