Triggering mechanism and secondary landslide analyses of the “7•23” Shuicheng landslide in Guizhou
-
摘要:
2019年7月23日，贵州省六盘水市水城区鸡场镇发生特大山体滑坡，造成了43人遇难，9人失踪。滑坡发生后，残留滑体堆积物与附近不稳定斜坡仍然威胁坡脚村民居住地。基于滑坡现场精细调查，探明了水城滑坡地质环境条件，阐述了滑坡的孕灾环境、诱发因素与破坏模式；首次对滑后残留滑体堆积物与附近不稳定斜坡进行了不同降雨条件下的稳定性分析。结果表明：极端降雨可能促使水城滑坡的大量堆积物发生二次滑坡运动；此外，基于流态滑体运动控制方程及数值求解，对二次失稳破坏后的滑体动力学过程及潜在致灾范围进行了预测。研究结果可对水城滑坡二次破坏的滑体动力致灾机理与坡脚村民生命财产的保障工作起到支撑作用。
Abstract:On July 23, 2019, a catastrophic landslide occurred in Jichang Town, Shuicheng District, Liupanshui City, Guizhou Province, resulting in the tragic loss of 43 lives, with 9 people still missing, and causing direct economic losses estimated at approximately 103 million Yuan. Following the landslide, significant debris and an unstable slope continued to threaten the nearby residences in the Pingzhai and Pingxing groups. Through comprehensive on-site investigations, this study identifies and analyzes both the geological environment and contributing factors of the Shuicheng landslide, providing an in-depth understanding of its triggering mechanisms. For the first time, a thorough stability analysis of the post-landslide residual deposits and the adjacent unstable slope under varying precipitation conditions is presented. The results indicate that extreme rainfall may trigger secondary landslide within the extensive debris deposits from the Shuicheng landslide. Additionally, we performed a dynamic behavior analysis of the unstable slope using rheological models and depth-averaged approaches. The findings provide essential insights into the dynamical mechanisms driving secondary landslide disasters and are crutial for safeguarding the lives and properties of residents at the slope toe.
-
Key words:
- Shuicheng landslide /
- triggering mechanism /
- slope stability /
- dynamic behavior
-
-
表 1 滑坡成因分析一览表
Table 1. Overview of landslide causation analysis of the Shuicheng landslide
主要
影响
因素地形
地貌滑坡体发育于波状起伏地形的斜坡体上，后缘为平台区，汇水面积较大。坡体呈“陡缓陡”交替分布，地面起伏较大，滑源区没有系统的排水通道，不利地表水排泄。斜坡上呈“陡缓陡”地形，陡坡部位临空条件较好，坡度35°～50°，临空高度大于10 m，为滑坡失稳提供了条件 地层
岩性根据钻探及物探资料显示，滑坡体主要为第四系坡堆积层及强风化玄武岩，强风化层呈散体-碎裂结构，抗剪强度较低；其次，大量地表水易下渗在强风化层界面上汇聚，长期受地下水浸泡影响，界面处岩土体强度易降低，不利坡体稳定 水文
条件根据现场调查来看，滑坡区受大气降雨影响明显。滑坡体后缘汇水面积较大，降雨条件下，后缘大量地表水漫流下渗，致使地下水水位抬高，并向滑坡体前缘斜坡体上排出。高水位的地下水对堆积体产生强大浮托力，不利斜坡稳定 诱发
外因降雨是滑坡形成的主要诱发因素，一方面增加了坡体自重，另一方面大量雨水沿覆盖层下渗，富集于滑带处，长期浸泡降低了滑带土的物理力学指标，不利于坡体稳定。同时后缘大面积的汇水抬高地下水水位，向沟道排出，对堆积体产生强大的浮托力，降低坡体稳定；
斜坡上公路开挖形成高边坡，改变了原有地形地貌，破坏原始斜坡力学平衡，且公路开挖形成的高陡边坡又为滑坡的形成提供了良好的位移空间变形模式 滑坡在强降雨作用下，大量雨水下渗浸泡后，产生强大浮托力，坡体在自重作用下，易沿底部强风化层界面向下部临空侧整体发生滑动变形，为一推移式变形破坏滑坡 破坏模式 综合现场调查、钻孔揭露及物探成果，水城区鸡场镇坪地村岔沟组滑坡物质组成分为三层，自上而下分别为：第四系堆积层，强风化玄武岩及中风化玄武岩层；根据钻探、物探资料及现场变形特征推测，滑坡的破坏模式可能为在堆积层及强风化玄武岩层范围内产生似圆弧型滑动，及在堆积层与基岩界面产生折线滑动 
下载: 导出CSV
表 2 稳定性计算结果表
Table 2. Slope stability calculation results
剖面 滑面 计算工况 稳定系数 评价 1−1′ 主要滑面 自重+天然水位 1.174 稳定 自重+ 1/3饱水 1.073 基本稳定 自重+2/3饱水 1.035 欠
稳定对照滑面 自重+附加荷载+天然水位 1.122 基本稳定 自重+附加荷载+1/3饱水 1.037 欠
稳定自重+附加荷载+2/3饱水 0.996 不
稳定2−2′ 主要滑面 自重+天然水位 1.135 基本稳定 自重+ 1/3饱水 1.021 欠
稳定自重+ 2/3饱水 0.989 不
稳定次级滑面 自重+天然水位 1.302 稳定 自重+1/3饱水 1.105 基本稳定 自重+ 2/3饱水 1.064 基本稳定
下载: 导出CSV
-
[1] 李滨,殷跃平,高杨,等. 西南岩溶山区大型崩滑灾害研究的关键问题[J]. 水文地质工程地质,2020,47(4):5 − 13. [LI Bin,YIN Yueping,GAO Yang,et al. Critical issues in rock avalanches in the karst mountain areas of southwest China[J]. Hydrogeology & Engineering Geology,2020,47(4):5 − 13. (in Chinese with English abstract)]
LI Bin, YIN Yueping, GAO Yang, et al. Critical issues in rock avalanches in the karst mountain areas of southwest China［J］. Hydrogeology & Engineering Geology, 2020, 47（4）: 5 − 13. （in Chinese with English abstract）
[2] 殷跃平,高少华. 高位远程地质灾害研究: 回顾与展望[J]. 中国地质灾害与防治学报,2024,35(1):1 − 18. [YIN Yueping, GAO Shaohua. Research on high-altitude and long-runout rockslides: Review and prospects[J]. The Chinese Journal of Geological Hazard and Control,2024,35(1):1 − 18. (in Chinese with English abstract)]
YIN Yueping, GAO Shaohua. Research on high-altitude and long-runout rockslides: Review and prospects［J］. The Chinese Journal of Geological Hazard and Control, 2024, 35（1）: 1 − 18. （in Chinese with English abstract）
[3] 许强,郑光,李为乐,等. 2018年10月和11月金沙江白格两次滑坡-堰塞堵江事件分析研究[J]. 工程地质学报,2018,26(6):1534 − 1551. [XU Qiang,ZHENG Guang,LI Weile,et al. Study on successive landslide damming events of Jinsha River in Baige village on October 11 and November 3,2018[J]. Journal of Engineering Geology,2018,26(6):1534 − 1551. (in Chinese with English abstract)]
XU Qiang, ZHENG Guang, LI Weile, et al. Study on successive landslide damming events of Jinsha River in Baige village on October 11 and November 3, 2018［J］. Journal of Engineering Geology, 2018, 26（6）: 1534 − 1551. （in Chinese with English abstract）
[4] 黄润秋,许强,等. 中国典型灾难性滑坡[M]. 北京:科学出版社,2008. [HUANG Runqiu,XU Qiang. Catastrophic landslides in China[M]. Beijing:Science Press,2008. (in Chinese)]
HUANG Runqiu, XU Qiang. Catastrophic landslides in China［M］. Beijing: Science Press, 2008. （in Chinese）
[5] ZHANG Yanbo,XING Aiguo,JIN Kaiping,et al. Investigation and dynamic analyses of rockslide-induced debris avalanche in Shuicheng,Guizhou,China[J]. Landslides,2020,17(9):2189 − 2203. doi: 10.1007/s10346-020-01436-0
[6] ZHUANG Yu,XING Aiguo,LENG Yangyang,et al. Investigation of characteristics of long runout landslides based on the multi-source data collaboration:A case study of the Shuicheng basalt landslide in Guizhou,China[J]. Rock Mechanics and Rock Engineering,2021,54(8):3783 − 3798. doi: 10.1007/s00603-021-02493-0
[7] 高浩源,高杨,贺凯,等. 贵州水城“7•23”高位远程滑坡冲击铲刮效应分析[J]. 中国岩溶,2020,39(4):535 − 546. [GAO Haoyuan,GAO Yang,HE Kai,et al. Impact and scraping effects of the high-elevation,long-runout “7•23” landslide in Shuicheng,Guizhou[J]. Carsologica Sinica,2020,39(4):535 − 546. (in Chinese with English abstract)]
GAO Haoyuan, GAO Yang, HE Kai, et al. Impact and scraping effects of the high-elevation, long-runout “7•23” landslide in Shuicheng, Guizhou［J］. Carsologica Sinica, 2020, 39（4）: 535 − 546. （in Chinese with English abstract）
[8] 郑光,许强,刘秀伟,等. 2019年7月23日贵州水城县鸡场镇滑坡-碎屑流特征与成因机理研究[J]. 工程地质学报,28(3):541 − 556. [ZHENG Guang,XU Qiang,LIU Xiuwei,et al. The Jichang landslide on July 23,2019 in Shuicheng,Guizhou:Characteristics and failure mechanism[J]. Journal of Engineering Geology,28(3):541 − 556. (in Chinese with English abstract)]
ZHENG Guang, XU Qiang, LIU Xiuwei, et al. The Jichang landslide on July 23, 2019 in Shuicheng, Guizhou: Characteristics and failure mechanism［J］. Journal of Engineering Geology, 28（3）: 541 − 556. （in Chinese with English abstract）
[9] 李华,史文兵,朱要强,等. 贵州省水城县“7•23”灾难性滑坡形成机制研究[J]. 自然灾害学报,2020,29(6):188 − 198. [LI Hua,SHI Wenbing,ZHU Yaoqiang,et al. Study on the formation mechanism of “7•23” catastrophic landslide in Shuicheng County,Guizhou Province,China[J]. Journal of Natural Disasters,2020,29(6):188 − 198. (in Chinese with English abstract)]
LI Hua, SHI Wenbing, ZHU Yaoqiang, et al. Study on the formation mechanism of “7•23” catastrophic landslide in Shuicheng County, Guizhou Province, China［J］. Journal of Natural Disasters, 2020, 29（6）: 188 − 198. （in Chinese with English abstract）
[10] 刘建强,许强,郑光,等. 贵州省鸡场滑坡地下水化学特征反映的水-岩(土)作用[J]. 水文地质工程地质,2023,50(2):132 − 140. [LIU Jianqiang,XU Qiang,ZHENG Guang,et al. Water-rock/soil interaction reflected by the chemical characteristics of groundwater of Jichang landslide in Guizhou Province[J]. Hydrogeology & Engineering Geology,2023,50(2):132 − 140. (in Chinese with English abstract)]
LIU Jianqiang, XU Qiang, ZHENG Guang, et al. Water-rock/soil interaction reflected by the chemical characteristics of groundwater of Jichang landslide in Guizhou Province［J］. Hydrogeology & Engineering Geology, 2023, 50（2）: 132 − 140. （in Chinese with English abstract）
[11] GUO Jian,YI Shujian,YIN Yanzhou,et al. The effect of topography on landslide kinematics:A case study of the Jichang town landslide in Guizhou,China[J]. Landslides,2020,17(4):959 − 973. doi: 10.1007/s10346-019-01339-9
[12] HUNGR O, FELL R, COUTURE R, et al. Estimating landslide motion mechanism, travel distance and velocity[M]. Landslide Risk Management. Boca Raton: CRC Press, 2005: 109 − 138.
[13] XING Aiguo,WANG Gonghui,LI Bin,et al. Long-runout mechanism and landsliding behaviour of large catastrophic landslide triggered by heavy rainfall in Guanling,Guizhou,China[J]. Canadian Geotechnical Journal,2015,52(7):971 − 981. doi: 10.1139/cgj-2014-0122
-
图(10)
表(2)
计量
- 文章访问数: 14
- PDF下载数: 1
- 施引文献: 0