Analysis on the formation causes of the moli landslide and river blockage risk in Guoye town, Zhouqu County
-
摘要: 受降雨的影响,2 021年2月26日至28日,舟曲县果耶镇磨里滑坡发生蠕动变形,坡体裂缝发育,变形迹象明显,共造成92户402人受灾,直接经济损失约1 446.3万元。本文以舟曲县果耶镇磨里滑坡为研究对象,通过遥感解译、无人机航拍和地质勘察等方法,深入了解磨里滑坡所处的地质环境、土体物理力学性质等,对该滑坡的成因进行了详细分析、对滑坡的稳定进行了理论计算和位移监测分析。在野外调查和钻探分析的基础上,采用Massflow数值模型对舟曲县果耶镇磨里滑坡进行数值模拟与预测,确定物源区范围及厚度以预测滑坡的堆积过程以及堵江风险,预测了滑坡堵江的高度以及对上游和下游区域造成的危害。结果表明:(1)磨里滑坡呈长舌状,形态和变形清晰明显,滑体由碎石土和破碎千枚岩组成,平均深度40 m,总体积2 120×104 m3,属特大型深层滑坡。(2)不利的地形条件、岩土体的软化、强烈的构造运动、降雨的入渗和前缘河水冲刷下切形成临空面是滑坡形成的主要因素。(3)该滑坡存在摧毁滑坡体房屋道路和堵江的风险,建议对受磨里滑坡威胁的居民尽快采取避险搬迁措施。本研究可为类似滑坡地质灾害链的成因机制和应急防控等提供参考。Abstract: Due to the heavy rainfall, from February 26th to 28th 2021, the Moli landslide in Guoye Town, Zhouqu County, experienced creeping deformation with the development of slope cracks and obnious signs of deformation. A total of of 92 households with 402 people were affected, causing a direct economic loss of approximately 14.463 million yuan. This study focuses on the Moli landslide in Guoye Town, where the geological environment and physical and mechanical properties of the soil were deeply understood through remote sensing interpretation, aerial photography, and geological investigation. The cause of the landslide formation was analyzed in detail, and the stability of the landslide was calculated theoretically and analyzed for displacement monitoring. Based on field investigation and drilling analysis, the Massflow numerical model was used to simulate and predict the Moli landslide in Guoye Town, Zhouqu County. The range and thickness of the source area were determined to predict the accumulation process of the landslide and the risk of river blocking. The height of the river blocking and the harm caused by the landslide to the upstream and downstream regions were predicted. The results showed that: (1) Moli landslide is a super-large deep landslide with a long tongue shape, clear shape and deformation, and composed of broken phyllite and broken stone soil. The average depth of the slide body is 40m, and the total volume is 21.2 million square meters. (2) The main factors of landslide formation are unfavorable topographic conditions, softening of rock and soil, strong tectonic movement, rainfall infiltration, and front river erosion. (3) The landslide has the risk of destroying the landslide houses, roads, and blocking the river. It is suggested that the residents threatened by the Moli landslide should take measures to avoid danger and relocate as soon as possible. This study can provide reference for the formation mechanism and emergency prevention and control of similar landslide geological disaster chains.
-
表 1 滑块滑带土取值表
Table 1. Property table of the soils at slide block slip zone
状态 容重( kN/m3) 强度指标 实验标准值 反演值 采用值 天然 18 内聚力C(KPa) 20.5 19.9 20.2 内摩擦角φ(°) 16.3 15.9 16.1 饱和 24 内聚力C(KPa) 18.5 17.9 18.2 内摩擦角φ(°) 15.3 14.9 15.1 表 2 滑坡体稳定性成果汇总表
Table 2. 2, Summary table of landslide stability results
计算工况 稳定系数 稳定状态 工况1:自重 1.070 基本稳定 工况2:自重+暴雨 0.925 不稳定 工况3:自重+地震 0.835 不稳定 表 3 滑坡动力过程模拟假设情景与参数
Table 3. Simulation scenarios and parameters for landslide dynamic process
情景 滑带土含水率 粘聚力(KPa) 内摩擦角(°) 情景一 6% 54.79 35 情景二 18% 23.05 24 情景三 30% 0.21 15 表 4 溃决洪水演进过程模拟假设情景与参数
Table 4. Simulation scenarios and parameters for evaluation of outburst flood
情景 河流流量
(m3/s)曼宁
系数抗剪强度
系数床负载
系数模拟时常
(h)情景四 20 0.04 0.13 1.5 15 情景五 15 0.04 0.13 1.5 15 -
[1] 胡卸文,黄润秋,朱海勇,等. 唐家山堰塞湖库区马铃岩滑坡地震复活效应及其稳定性研究[J]. 岩石力学与工程学报,2009,28(6):1270 − 1278. [HU Xiewen,HUANG Runqiu,ZHU Haiyong,et al. Earthquake reactivation effects and stability study of malingyan landslide in Tangjiashan dammed lake[J]. Chinese Journal of Rock Mechanics and Engineering,2009,28(6):1270 − 1278. (in Chinese with English abstract) [2] 卢万年. 用空气动力学分析坡体高速滑坡的滑行问题[J]. 地球科学与环境学报,1991,13(4):77 − 85. [LU Wannian. Airo-dynamic approach to sliding problems of high landslide[J]. Journal of Earth Science and Enivronmental,1991,13(4):77 − 85. (in Chinese with English abstract) [3] 黄润秋, 王士天, 张悼元. 斜坡岩体高速滑动的“滚动摩擦”机制[A]. 见: 工程地质科学新进展[C]. 成都: 成都科技大学出版社, 1989, 318-325HUANG Runqiu, WANG Shitian, ZHANG Xiaoyuan. “Rolling friction” mechanism“A” for high-speed sliding of slope rock mass. See: New Progress in engineering geology [C]. Chengdu: Chengdu University of Science and Technology Press, 1989, 318-325]. [4] 胡广韬,赵法锁,李丽,等. 基岩地区高速滑坡的多级冲程与超前溅泥气浪[J]. 地球科学与环境学报,1988,10(1):79 − 87. [HU Guangtao,ZHAO Fasuo,LI Li,et al. Multiple-stroking of high-speed landslides and overstepping gas billows including mud in bed rock areas[J]. Journal of Earth Science and Enivronmental,1988,10(1):79 − 87. (in Chinese with English abstract) [5] 廖军,邓涛,周越良,等. 降雨作用下第四系堆积体路堤稳定性[J]. 科学技术与工程,2021,21(23):10090 − 10097. [LIAO Jun,DENG Tao,ZHOU Yueliang,et al. Stability of quaternary accumulation embankment under rainfall[J]. Science Technology and Engineering,2021,21(23):10090 − 10097. (in Chinese with English abstract) [6] 云烨,吕孝雷,付希凯,等. 星载InSAR技术在地质灾害监测领域的应用[J]. 雷达学报,2020,9(1):73 − 85. [YUN Ye,LÜ Xiaolei,FU Xikai,et al. Application of spaceborne interferometric synthetic aperture radar to geohazard monitoring[J]. Journal of Radars,2020,9(1):73 − 85. (in Chinese with English abstract) [7] 代聪,李为乐,陆会燕,等. 甘肃省舟曲县城周边活动滑坡InSAR探测[J]. 武汉大学学报(信息科学版),2021,46(7):994 − 1002. [DAI Cong,LI Weile,LU Huiyan,et al. Active landslides detection in Zhouqu County,Gansu Province using InSAR technology[J]. Geomatics and Information Science of Wuhan University,2021,46(7):994 − 1002. (in Chinese with English abstract) [8] 张国帅,王晓亮,夏建新. 入渗条件下颗粒堆积体稳定性试验研究[J]. 泥沙研究,2021,46(5):68 − 73. [ZHANG Guoshuai,WANG Xiaoliang,XIA Jianxin. Experimental study on stability of particle accumulation under infiltration[J]. Journal of Sediment Research,2021,46(5):68 − 73. (in Chinese with English abstract) [9] 石固林,徐浪,张璇钰,等. 西山村滑坡时序形变的SBAS-InSAR监测[J]. 测绘科学,2021,46(2):93 − 98. [SHI Gulin,XU Lang,ZHANG Xuanyu,et al. Monitoring time series deformation of Xishancun landslide with SBAS-InSAR[J]. Science of Surveying and Mapping,2021,46(2):93 − 98. (in Chinese with English abstract) [10] 朱庆,曾浩炜,丁雨淋,等. 重大滑坡隐患分析方法综述[J]. 测绘学报,2019,48(12):1551 − 1561. [ZHU Qing,ZENG Haowei,DING Yulin,et al. A review of major potential landslide hazards analysis[J]. Acta Geodaetica et Cartographica Sinica,2019,48(12):1551 − 1561. (in Chinese with English abstract) [11] 张雨林,石惊涛,涂国祥,等. 粗、巨颗粒富集位置对堆积体降雨入渗的影响[J]. 水利水运工程学报,2021(5):76 − 83. [ZHANG Yulin,SHI Jingtao,TU Guoxiang,et al. Influence of coarse and giant particles enrichment position on rainfall infiltration of accumulation body[J]. Hydro-Science and Engineering,2021(5):76 − 83. (in Chinese with English abstract) [12] 柴贺军,刘汉超,张倬元. 中国滑坡堵江的类型及其特点[J]. 成都理工学院学报,1998,25(3):411 − 416. [CHAI Hejun,LIU Hanchao,ZHANG Zhuoyuan. Study on the categories of landslide damming of rivers and their characteristics[J]. Journal of Chengdu University of Technology,1998,25(3):411 − 416. (in Chinese with English abstract) [13] 李娜. 云南省滑坡堵江灾害及其对策[C]. 滑坡文集(9). 北京: 铁道出版社, 1992LI Na. Landslide Blocking River disaster in Yunnan province and its countermeasures[C]. Landslide Essays (9). Beijing: Railway Press, 1992. [14] 柴贺军,刘汉超,张倬元. 滑坡堵江的基本条件[J]. 地质灾害与环境保护,1996,7(1):41 − 46. [CHAI Hejun,LIU Hanchao,ZHANG Zhuoyuan. The main conditions of landslide dam[J]. Journal of Geological Hazards and Enveronment Preservation,1996,7(1):41 − 46. (in Chinese with English abstract) [15] 于宝国,边波,李春龙,等. 基于知识图谱的碎石土堆积体滑坡研究热点及发展趋势[J]. 地球科学前沿(汉斯),2021(10):1326 − 1340. [YU B G,BIAN B,LI C L,et al. Research hotspot and development trend of gravel soil accumulation landslide based on knowledge graph[J]. Frontiers of Earth Science (Hans),2021(10):1326 − 1340. (in Chinese with English abstract) [16] 李忠生. 国内外地震滑坡灾害研究综述[J]. 灾害学,2003,18(4):64 − 70. [LI Zhongsheng. The state of the art of the research on seismic landslide hazard at home and abroad[J]. Journal of Catastrophology,2003,18(4):64 − 70. (in Chinese with English abstract) [17] 方玉树. 超大型滑坡动力学问题研究[J]. 水文地质工程地质,1988,15(6):20 − 24. [FANG Yushu. Study on dynamic problems of super-large landslide[J]. Hydrogeology & Engineering Geology,1988,15(6):20 − 24. (in Chinese) [18] 刘建康,程尊兰,佘涛. 云南鲁甸红石岩堰塞湖溃坝风险及其影响[J]. 山地学报,2016,34(2):208 − 215. [LIU Jiankang,CHENG Zunlan,SHE Tao. Assessment of dam failure and secondary hazards for hongshiyan dammed lake caused by Ludian earthquake in niulanjiang river[J]. Mountain Research,2016,34(2):208 − 215. (in Chinese with English abstract) [19] 贺小黑,彭鑫,谭建民,等. 地下水渗流对崩坡积滑坡稳定性和变形的影响—以湖南安化春风滑坡群为例[J]. 中国地质灾害与防治学报,2020,31(6):96 − 103. [HE Xiaohei,PENG Xin,TAN Jianmin,et al. Influence of groundwater seepage on stability and deformation of colluvial deposit landslide:Taking Chunfeng Landslide group in Anhua County of Hunan Province as an example[J]. The Chinese Journal of Geological Hazard and Control,2020,31(6):96 − 103. (in Chinese with English abstract) [20] TANG Y M,SHU H P,XUE Q A,et al. Field monitoring-based and theoretical analysis of Baota Mountain landslide stability[J]. Advances in Civil Engineering,2021,2021:1 − 16. [21] FLAGEOLLET J C,MAQUAIRE O,MARTIN B,et al. Landslides and climatic conditions in the Barcelonnette and Vars Basins (Southern French Alps,France)[J]. Geomorphology,1999,30(1/2):65 − 78. -