Reactivation and deformation mechanism of ancient landslides by excavation
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摘要: 以三峡库区兴山县大礼溪村古滑坡为例,通过地质勘察、近1 a的现场宏观巡查、人工GPS位移监测数据、自动GPS监测数据等,在剖析该滑坡存在的古滑坡特征的基础上,分析了滑坡复活过程中地表裂缝发育的时空规律以及变形特征,并结合Geo-Studio模拟确定了开挖和降雨两种作用对古滑坡复活变形的影响及主次关系。研究表明:①大礼溪滑坡为地质历史时期形成的含软层中—陡倾顺层岩质古滑坡;②滑坡复活变形与开挖作用密切相关,前期集中于临近最早开挖区域的前缘Q3附近,并沿着开挖方向逐渐在前缘Q4、Q5出现,最终在前缘Q5附近演化出次级滑坡,与此同时,纵向上变形逐渐向中后部推进,表现出渐进后退的发育特征;③开挖作用是滑坡变形复活的主要因素和诱发因素,降雨为激发因素,两者共同作用促使变形持续发展。Abstract: The Dalixi ancient landslide in Xingshan County in the Three Gorges Reservoir area is taken as an example. Based on the analysis of its characteristics, the deformation characteristics and temporal-spatial laws of surface cracks of the ancient landside in the process of landslide revival are analyzed by use of geological survey, site inspection for nearly one year, artificial GPS displacement monitoring data and automatic monitoring data. Based on the Geo-Studio simulation, the influences of excavation and rainfall on the revival deformation of the ancient landslide and the primary and secondary relationships are determined. The results show that: (1) The Dalixi landslide is a middle-steep consequent ancient rock landslide with soft layer in geological history period. (2) The deformation of Dalixi landslide is closely related to excavation. In the early stage, it concentrates near the leading edge Q3 of the first excavation area, and gradually appears along the excavation direction at the leading edge Q4 and Q5, and finally evolves into the secondary landslides near the leading edge Q5. At the same time, the vertical deformation gradually advances to the middle and rear, showing the characteristics of progressive retrogression. (3) The excavation is the inducing factor for the revival of landslide deformation, and the rainfall is the stimulating factor. Both of them work together to promote the sustainable development of landslide deformation
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Keywords:
- ancient landslide /
- deformation reactivation /
- excavation /
- deformation feature
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表 1 大礼溪滑坡地表裂缝统计表
Table 1 Statistical data of cracks of Dalixi landslide
编号 走向/(°) 性质 位置 出现时间 T1~T9 155~235 前缘Q3附近拉张裂缝,长约3~30 m,宽约1~5 cm,无明显上下错动,可见约深度5~10 cm 前缘Q3 2017年2月 T10~T17 130~240 前缘Q4附近拉张裂缝,长约5~40 m,宽约3~30 cm,局部有错动约5~20 cm,可见约深度5~15cm 前缘Q4 2017年3月,4月 T18~T28 130~160 前缘Q5附近拉张、剪切裂缝,断续延伸5~50 m,宽约10~35 cm,局部有错动约200 cm,可见约深度10~30 cm 前缘Q5 2017年5月次级滑坡发生时产生 T29~T30 160~190 拉张裂缝,长约50~60 m,宽约3~10 cm,可见约深度10 cm 滑体中部 2017年7月 T31~T35 170~260 拉张裂缝,长约4~8 m,宽约1~3 cm,可见约深度5~10 cm 滑体中部 2017年7月 T36,T40~T57 145~170 滑体拉张裂缝,长约5~40 m,宽约1~10 cm,局部有明显错动约150 cm,可见约深度15~30 cm 滑体中后部 2017年10月 T37~T39,T58~T65 155~230 后缘拉张、剪切裂缝,长约5~10 m,宽约5~15 cm,局部有上下错动约5~10 cm,可见约深度20cm 后缘及两侧边界裂缝 2017年10月 表 2 大礼溪滑坡物理力学参数
Table 2 Physical and mechanical parameters of Dalixi landslide
材料 重度/(kN·m-3) 黏聚力c/kPa 内摩擦角φ/(°) 泊松比 模拟 室内试验 模拟 室内试验 滑体 24.5 31.5 33.0 21.0 21.0 0.30 滑带 22.0 23.0 23.6 16.6 17.0 0.35 滑床 25.0 — — — — — -
[1] CRUDEN D M, VARNES D J. Landslide types and processes, special report, transportation research board[J]. National Academy of Sciences, 1996, 247: 36-75.
[2] BURDA J, HARTVICH F, VALENTA J, et al. Climate- induced landslide reactivation at the edge of the Most Basin (Czech Republic): progress towards better landslide prediction[J]. Natural Hazards and Earth System Sciences, 2013, 13: 361-374. doi: 10.5194/nhess-13-361-2013
[3] RONCHETTI F, BORGATTI L, CERVI F, et al. The Valoria landslide reactivation in 2005 — 2006 (Northern Apennines, Italy)[J]. Landslides, 2007, 4(2): 189-195. doi: 10.1007/s10346-006-0073-9
[4] DENG H, WU L Z, HUANG R Q, et al. Formation of the Siwanli ancient landslide in the Dadu River, China[J]. Landslides, 2017, 14(1): 385-394. doi: 10.1007/s10346-016-0756-9
[5] 吴瑞安, 张永双, 郭长宝, 等. 川西松潘上窑沟古滑坡复活特征及危险性预测研究[J]. 岩土工程学报, 2018, 40(9): 1659-1667. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201809014.htm WU Rui-an, ZHANG Yong-shuang, GUO Chang-bao. Reactivation characteristics and hazard prediction of Shangyaogou ancient landslide in Songpan County of Sichuan Province[J]. Chinese Journal of Geotechnical Engineering, 2018, 40(9): 1659-1667. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201809014.htm
[6] 郭健, 许模, 赵勇, 等. 黑水河库区某古滑坡形成及复活机制[J]. 成都理工大学学报(自然科学版), 2013, 40(6): 721-728. https://www.cnki.com.cn/Article/CJFDTOTAL-CDLG201306012.htm GUO Jian, XU Mo, ZHAO Yong, et al. Formation and reactivation mechanism of an ancient landslide in Heishui reservoir of Minjiang River, China[J]. Journal of Chengdu University of Technology, 2013, 40(6): 721-728. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-CDLG201306012.htm
[7] 李明辉, 李浩然, 王东辉. 大渡河上游亚喀则滑坡复活变形机理及发展趋势分析[J]. 水土保持研究, 2014, 21(1): 305-309. https://www.cnki.com.cn/Article/CJFDTOTAL-STBY201401059.htm LI Ming-hui, LI Hao-ran, WANG Dong-hui. The revival mechanism and development tendency of Yakaze landslide in the upper reaches of Dadu River[J]. Research of Soil and Water Conservation, 2014, 21(1): 305-309. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-STBY201401059.htm
[8] 付博, 严明, 李波, 等. 岷江某水电站库区#1滑坡复活机制分析[J]. 工程地质学报, 2008, 16(1): 11-16. https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ200801004.htm FU Bo, YAN Ming, LI Bo, et al. Analysis of revivification mechanism for a landslide on a hydropower station reservoir in Minjiang[J]. Journal of Engineering Geology, 2008, 16(1): 11-16. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ200801004.htm
[9] WANG J J, LIANG Y, ZHANG H P, et al. A loess landslide induced by excavation and rainfall[J]. Landslides, 2014, 11(1): 141-152.
[10] GU D M, HUANG D, YANG W D, et al. Understanding the triggering mechanism and possible kinematic evolution of a reactivated landslide in the Three Gorges Reservoir[J]. Landslides, 2017, 14(6): 2073-2087.
[11] 李明辉, 郑万模, 石胜伟, 等. 丹巴县甲居滑坡复活机制及其稳定性分析[J]. 山地学报, 2008, 26(5): 577-582. https://www.cnki.com.cn/Article/CJFDTOTAL-SDYA200805013.htm LI Ming-hui, ZHENG Wan-mo, SHI Sheng-wei, et al. The revival mechanism and stability analysis to Jiaju landslide of Danba county in Sichuan province[J]. Journal of Mountain Science, 2008, 26(5): 577-582. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-SDYA200805013.htm
[12] 张永双, 郭长宝, 周能娟. 金沙江支流冲江河巨型滑坡及其局部复活机理研究[J]. 岩土工程学报, 2013, 35(3): 445-453. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201303008.htm ZHANG Yong-shuang, GUO Chang-bao, ZHOU Neng-juan. Characteristics of Chongjianghe landslide at a branch of Jinsha River and its local reactivation mechanism[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(3): 445-453. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201303008.htm
[13] 哈秋舲. 三峡工程永久船闸陡高边坡各向异性卸荷岩体力学研究[J]. 岩石力学与工程学报, 2001, 26(5): 605-610. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX200105003.htm HA Qiu-ling. Study on the anisotropic unloading rock mass mechanics for the steep-high rock slope of the three gorges project permanent shiplock[J]. Chinese Journal of Rock Mechanics and Engineering, 2001, 26(5): 605-610. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX200105003.htm
[14] 盛谦. 深挖岩质边坡开挖扰动区与工程岩体力学性状研究[D]. 武汉: 中国科学院武汉岩土力学研究所, 2002. SHENG Qian. Excavation Disturbed Zone of Deep Cutting Rock Slopes and Mechanics Behaviour of Engineering Rock Mass[D]. Wuhan: Institute of Rock and Soil Mechanics, The Chinese Academy of Sciences, 2002. (in Chinese)
[15] 黄润秋, 林峰, 陈德基, 等. 岩质高边坡卸荷带形成及其工程性状研究[J]. 工程地质学报, 2001, 9(3): 228-229. https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ200103000.htm HUANG Run-qiu, LIN Feng, CHEN De-ji, et al. Formation mechanism of unloading fracture zone of high slopes and its engineering behaviors[J]. Journal of Engineering Geology, 2001, 9(3): 228-229. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-GCDZ200103000.htm
[16] 李明, 张嘎, 李焯芬, 等. 开挖对边坡变形影响的离心模型试验研究[J]. 岩土工程学报, 2011, 33(4): 667-672. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201104030.htm LI Ming, ZHANG Ga, LEE C F, et al. Centrifugal model tests on excavation-induced deformation of slopes[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(4): 667-672. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201104030.htm
[17] 许强, 汤明高, 黄润秋. 大型滑坡监测预警与应急处置[M]. 北京: 科学出版社, 2015. XU Qiang, TANG Ming-gao, HUANG Run-qiu. Monitoring, Warning and Emergency Treatment of Large Landslide[M]. Beijing: Science Press, 2015. (in Chinese)
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