Deformation mechanism and stability evaluation of Dingjiapo landslide considering the matric suction of unsaturated soil
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摘要:
丁家坡滑坡位于云阳县黄石镇中湾村，对拟建的云阳—开州（云开）高速公路安全具有潜在的威胁。为了查明丁家坡滑坡特征，开展了野外工程地质测绘、钻探与试验测试，采用Geo-studio完全耦合计算模式分析了不同降雨工况下滑坡渗流场、应力场、位移场的变化，考察了基质吸力在滑坡稳定性评价中的作用，并计算了不同降雨历时、降雨强度下滑坡的稳定性系数。结果表明：（1）丁家坡滑坡的斜坡地形、松散的岩性、潜在的临空面等因素决定了滑坡的形成与发育，坡体渗透性较好，降雨作用激励滑坡的变形，目前该滑坡处于蠕滑阶段；（2）降雨入渗后，坡体孔隙水压力增加，基质吸力减小，有效应力和抗剪强度降低，在土-岩界面形成剪应力集中，产生应变和位移，滑坡变形破坏；（3）高强度短历时的降雨使坡体浅层迅速饱和，易形成浅层滑，低强度长历时的降雨使坡体浸润较深，易造成深部滑动，其潜在滑动面主要为土-岩界面；（4）在非饱和状态下土体基质吸力对滑坡的稳定性具有重要影响；（5）目前滑坡处于基本稳定状态，一旦发生降雨，滑坡稳定性将降低，降雨历时越久、降雨强度越大，滑坡越易失稳。相对于滑坡Ⅱ区，滑坡Ⅰ区对云开高速公路安全的影响更大，应该重点对滑坡Ⅰ区进行防护治理。该研究可为工程设计、施工及滑坡的预警预报提供依据。
Abstract:The rainfall-induced Dingjiapo landslide poses a potential threat to the safety of the proposed Yunyang to Kaizhou (Yunkai) expressway. In order to identify the characteristics of Dingjiapo landslide, field engineering geological mapping, drilling and tests are carried out, and a numerical simulation code Geo-studio in a fully coupled computing mode is used to analyze the variations of landslide seepage field, stress field and displacement field under different rainfall conditions. The role of matrix suction in landslide stability evaluation is analyzed and the landslide stability factors under different rainfall duration and rainfall intensity are estimated. The results show that the slope topography, loose soil and rock characteristics and potential free surface of slope determine the landslide formation and development, the permeability of the landslide body is relatively high and the rainfall stimulates the landslide deformation. The landslide is currently in a creep stage with a few fissures in the central and these fissures show signs of widening during the rainy season. Following the rainfall infiltration, pore water pressure rises, matrix suction declines, effective stress and shear strength also decline, and shear stress concentration occurs in the soil-rock interface, which causes strain and displacement of the slope and deformation and damage of the landslide. High-intensity short-term rainfall could rapidly infiltrate the shallow soil and induce a shallow slide in the saturated section. Low-intensity long-term rainfall can saturate the deep soil and cause a deep landslide with the soil-rock interface as a slip surface. The matrix suction has an important influence on the stability of soil landslide. The stability analysis results show that this landslide at present is in a basically stable state and the stability factor would drop in case of rainfall. The longer the rain lasts and the higher the rainfall intensity is, the lower the stability factor will be. The landslide I area has a greater impact on the safety of Yunkai Expressway than the landslide II area and more attention should be paid to the protection and treatment of the landslide I area.
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Key words:
- landslide /
- deformation mechanism /
- rainfall infiltration /
- matrix suction /
- stability evaluation
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表 1 岩土体的物理参数
Table 1. Physical parameters of the rock and soil
岩土介质/参数 滑坡Ⅰ区 滑坡Ⅱ区 滑床 粉质黏土夹碎石块 粉砂质泥岩 中砂岩 天然重度/（kN·m−3） 19.7 19.7 25.1 24.7 饱和重度/（kN·m−3） 20.0 20.0 − − 天然黏聚力/kPa 13.0 15.0 − − 黏聚力（饱和）/kPa 10.5 12.8 − − 天然内摩擦角/（°） 10.5 13.0 − − 内摩擦角（饱和）/（°） 8.6 10.6 − − 弹性模量/MPa 10.0 10.0 4 030 30 000 泊松比 0.30 0.30 0.29 0.20 渗透系数/（m·d−1） 1.35 1.35 0.000 5 0.01 注：“−”表示参数不需要设置，为无。 
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[1] 熊珅,易武,王力,等. 三峡库区八字门滑坡变形破坏机理分析[J]. 中国地质灾害与防治学报,2019,30(5):9 − 18. [XIONG Shen,YI Wu,WANG Li,et al. Analysis of deformation and failure mechanism of Bazimen landslide in Three Gorges Reservoir area[J]. The Chinese Journal of Geological Hazard and Control,2019,30(5):9 − 18. (in Chinese with English abstract) doi: 10.16031/j.cnki.issn.1003-8035.2019.05.02
[2] 李德营,徐勇,殷坤龙,等. 降雨型滑坡高速运动与堆积特征模拟研究:以宁乡县王家湾滑坡为例[J]. 地质科技情报,2019,38(4):225 − 230. [LI Deying,XU Yong,YIN Kunlong,et al. Simulation of high-speed movement and accumulation characteristics of rainfall-induced landslide:a case of wangjiawan landslide in Ningxiang County[J]. Geological Science and Technology Information,2019,38(4):225 − 230. (in Chinese with English abstract)
[3] 黄晓虎,易武,龚超,等. 开挖致使古滑坡复活变形机理研究[J]. 岩土工程学报,2020,42(7):1276 − 1285. [HUANG Xiaohu,YI Wu,GONG Chao,et al. Reactivation and deformation mechanism of ancient landslides by excavation[J]. Chinese Journal of Geotechnical Engineering,2020,42(7):1276 − 1285. (in Chinese with English abstract)
[4] 马凤山,李国庆,张亚民,等. 西气东输管道靖边-延川段地质灾害遥感识别及危险性评价[J]. 工程地质学报,2008,16(增刊1):138 − 144. [MA Fengshan,LI Guoqing,ZHANG Yamin,et al. Geological hazard evaluation of oil-gas pipeling in loess area based on multiple remote sensing information[J]. Journal of Engineering Geology,2008,16(Sup1):138 − 144. (in Chinese with English abstract)
[5] 蒲娉璠. 重庆市滑坡灾害时空分布特征与易发性评价研究[D]. 上海: 华东师范大学, 2016
PU Pingfan. Analysis of temporal and spatial characteristics of landslide disaster and landslide susceptibility assessment in Chongqing[D]. Shanghai: East China Normal University, 2016. （in Chinese with English abstract）
[6] 付宏渊,陈镜丞,曾铃,等. 降雨对炭质泥岩-土分层路堤渗流与变形影响的模型试验[J]. 中南大学学报(自然科学版),2018,49(11):2852 − 2860. [FU Hongyuan,CHEN Jingcheng,ZENG Ling,et al. Model test on effect of rainfall on seepage and deformation of carbonaceous mudstone-soil stratified embankment[J]. Journal of Central South University (Science and Technology),2018,49(11):2852 − 2860. (in Chinese with English abstract) doi: 10.11817/j.issn.1672-7207.2018.11.027
[7] PAN Y,WU G,ZHAO Z,et al. Analysis of rock slope stability under rainfall conditions considering the water-induced weakening of rock[J]. Computers and Geotechnics,2020,128:103806. doi: 10.1016/j.compgeo.2020.103806
[8] 卫童瑶,殷跃平,高杨,等. 三峡库区巫山县塔坪H1滑坡变形机制[J]. 水文地质工程地质,2020,47(4):73 − 81. [WEI Tongyao,YIN Yueping,GAO Yang,et al. Deformation mechanism of the Taping H1 landslide in Wushan County in the Three Gorges Reservoir area[J]. Hydrogeology & Engineering Geology,2020,47(4):73 − 81. (in Chinese with English abstract)
[9] 李冬冬. 降雨诱发豫西锁固型滑坡演化机理模型试验研究[D]. 郑州: 华北水利水电大学, 2020
LI Dongdong. Experimental study on the evolution mechanism of landslides with locked section induced by rainfall infiltration in western Henan Province[D]. Zhengzhou: North China University of Water Resources and Electric Power, 2020（in Chinese with English abstract）
[10] 张勇,温智,程英建. 四川巴中市滑坡灾害与降雨雨型关系探讨[J]. 水文地质工程地质,2020,47(2):178 − 182. [ZHANG Yong,WEN Zhi,CHENG Yingjian. A discussion of the relationship between landslide disaster and rainfall types in Bazhong of Sichuan[J]. Hydrogeology & Engineering Geology,2020,47(2):178 − 182. (in Chinese with English abstract)
[11] 徐辉,刘海知. 诱发滑坡的多尺度降雨特征[J]. 山地学报,2019,37(6):858 − 867. [XU Hui,LIU Haizhi. Multi-scale rainfall characteristics of rainfall-induced landslides[J]. Mountain Research,2019,37(6):858 − 867. (in Chinese with English abstract)
[12] 曾昌禄, 李荣建, 关晓迪, 等. 不同雨强条件下黄土边坡降雨入渗特性模型试验研究[J]. 岩土工程学报, 2020, 42（增刊1）: 111 − 115
ZENG Changlu, LI Rongjian, GUAN Xiaodi, et al. Experimental study on rainfall infiltration characteristics of loess slopes under different rainfall intensities[J]. Chinese Journal of Geotechnical Engineering, 2020, 42（Sup 1）: 111 − 115. （in Chinese with English abstract）
[13] 李新卫,晏鄂川,李辉. 暴雨作用下铜仁地区典型滑坡变形机理研究[J]. 人民长江,2016,47(7):44 − 49. [LI Xinwei,YAN Echuan,LI Hui. Study on deformation mechanism of typical landslide triggered by rainstorm in Tongren area of Guizhou Province[J]. Yangtze River,2016,47(7):44 − 49. (in Chinese with English abstract)
[14] 霍志涛,李高,王力,等. 降雨型滑坡浅层滑动对土体含水率变化的响应[J]. 长江科学院院报,2022,39(7):110 − 117. [HUO Zhitao,LI Gao,WANG Li,et al. Response of shallow sliding of rainfall-type landslide to the change of soil moisture cntent[J]. Journal of Yangtze River Scientific Research Institute,2022,39(7):110 − 117. (in Chinese with English abstract) doi: 10.11988/ckyyb.20210211
[15] BISHOP A W,BLIGHT G E. Some aspects of effective stress in saturated and partly saturated soils[J]. Géotechnique,1963,13(3):177 − 197.
[16] FREDLUND D G,MORGENSTERN N R,WIDGER R A. The shear strength of unsaturated soils[J]. Canadian Geotechnical Journal,1978,15(3):313 − 321. doi: 10.1139/t78-029
[17] 付宏渊,马吉倩,史振宁,等. 非饱和土抗剪强度理论的关键问题与研究进展[J]. 中国公路学报,2018,31(2):1 − 14. [FU Hongyuan,MA Jiqian,SHI Zhenning,et al. Key issues and research progress of shear strength theory of unsaturated soil[J]. China Journal of Highway and Transport,2018,31(2):1 − 14. (in Chinese with English abstract) doi: 10.3969/j.issn.1001-7372.2018.02.001
[18] 王新刚, 谷天峰, 王家鼎. 基质吸力控制下的非饱和黄土三轴蠕变试验研究[J]. 水文地质工程地质, 2017, 44（4）: 57-61
WANG Xingang, GU Tianfeng, WANG Jiading, Research on the triaxial creep test of unsaturated loess under the matric suction control[J]. Hydrogeology & Engineering Geology, 2017, 44（4）: 57-61. （in Chinese with English abstract）
[19] 郑文晓,甘建军,李荐华. 基质吸力对灰岩区滑带土强度影响的试验分析[J]. 长江科学院院报,2020,37(7):120 − 124. [ZHENG Wenxiao,GAN Jianjun,LI Jianhua. Experimental study on effect of matric suction on strength of slip soil in limestone zone[J]. Journal of Yangtze River Scientific Research Institute,2020,37(7):120 − 124. (in Chinese with English abstract) doi: 10.11988/ckyyb.20190278
[20] WANG H,SUN P,WANG G,et al. Experimental and numerical study of shallow loess slope failure induced by irrigation[J]. CATENA,2021,206:105548. doi: 10.1016/j.catena.2021.105548
[21] 吴俊杰,王成华,李广信. 非饱和土基质吸力对边坡稳定的影响[J]. 岩土力学,2004,25(5):732 − 736. [WU Junjie,WANG Chenghua,LI Guangxin. Influence of matric suction in unsaturated soils on slope stability[J]. Rock and Soil Mechanics,2004,25(5):732 − 736. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-7598.2004.05.013
[22] 黄达,匡希彬,罗世林. 三峡库区藕塘滑坡变形特点及复活机制研究[J]. 水文地质工程地质,2019,46(5):127 − 135. [HUANG Da,KUANG Xibin,LUO Shilin. A study of the deformation characteristics and reactivation mechanism of the Outang landslide near the Three Gorges Reservoir of China[J]. Hydrogeology & Engineering Geology,2019,46(5):127 − 135. (in Chinese with English abstract) doi: 10.16030/j.cnki.issn.1000-3665.2019.05.17
[23] LU N, WILLIAM J LIKOS. 非饱和土力学[M]. 韦昌富, 侯龙, 简文星, 译. 北京: 高等教育出版社, 2012: 161 − 192
LU N, WILLIAM J LIKOS. Unsaturated soil mechanics[M]. WEI Changfu, HOU Long, JIAN Wenxing, trans. Beijing: Higher Education Press, 2012: 161 − 192. （in Chinese）
[24] 黄观文,王家兴,杜源,等. 顾及降雨及库水位因素的滑坡时滞分析与预测—以三峡库区新铺滑坡为例[J]. 地球科学与环境学报,2021,43(3):621 − 631. [HUANG Guanwen,WANG Jiaxing,DU Yuan,et al. Time-delay analysis and prediction of landslide considering precipitation and reservoir water level:A case study of Xinpu landslide in Three Gorges Reservoir area,China[J]. Journal of Earch Sciences and Environment,2021,43(3):621 − 631. (in Chinese with English abstract)
[25] 何坤,胡卸文,马国涛,等. 四川省盐源玻璃村特大型玄武岩古滑坡复活机制[J]. 岩土力学,2020,41(10):3443 − 3455. [HE Kun,HU Xiewen,MA Guotao,et al. The reactivated mechanism of Boli Village giant ancient basalt landslide in Yanyuan,Sichuan[J]. Rock and Soil Mechanics,2020,41(10):3443 − 3455. (in Chinese with English abstract) doi: 10.16285/j.rsm.2019.2168
[26] GEO-SLOPE International Ltd. 中仿科技（CnTech）公司, 译. 非饱和土体渗流分析软件SEEP/W用户指南[M]. 北京: 冶金工业出版社, 2011, 8: 141 − 149
Seepage modeling with SEEP/W 2007[M]. Beijing: Metallurgical Industry Press, 2011, 8: 141 − 149
[27] VAN GENUCHTEN M T. A closed-form equation for predicting the hydraulic conductivity of unsaturated soils[J]. Soil Science Society of America Journal,1980,44(5):892 − 898. doi: 10.2136/sssaj1980.03615995004400050002x
[28] FREDLUND D G,XING A. Equations for the soil-water characteristic curve[J]. Canadian Geotechnical Journal,1994,31(4):521 − 532. doi: 10.1139/t94-061
[29] FREDLUND D G,XING A,FREDLUND M D,et al. The relationship of the unsaturated soil shear strength to the soil-water characteristic curve[J]. Canadian Geotechnical Journal,1996,33(3):440 − 448. doi: 10.1139/t96-065
[30] VANAPALLI S K,FREDLUND D G,PUFAHL D E,et al. Model for the prediction of shear strength with respect to soil suction[J]. Canadian Geotechnical Journal,1996,33(3):379 − 392. doi: 10.1139/t96-060
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