Analysis of sliding mechanism of the cut slopes with multi-weak interlayers under rainfall
-
摘要: 本文基于抚顺西露天矿南帮滑坡工程实例，分析地下水及降雨入渗作用下顺倾软弱夹层边坡失稳的水力学模式，采用FLAC3D软件对抚顺西露天矿南帮边坡在地下水及降雨入渗作用下边坡变形的演化过程进行数值模拟分析，总结地下水及降雨入渗作用下顺倾多软弱夹层边坡的滑动规律。结果表明：降雨入渗和地下水的流动对坡体产生渗透压力，坡体破裂面大量发育，最大合位移约为1.27 m，形成多阶段滑坡，整体呈现混合式滑坡；边坡变形破坏期间，坡顶附近易沿弱层产生拉涨破坏，为地表水渗透和地下水的运移提供通道，并呈现多滑面的特点，形成贯通的剪切破坏面，进一步导致边坡的多段变形；地下水及降雨入渗影响下，边坡弱层含水率累积增加，损伤破裂，体积应变增量降低，有效应力降低，孔压累积上升，抗剪强度减低，从而诱发滑坡。相比降雨工况下，采用不同坡高高度回填压脚防护的边坡具有较高的安全系数，考虑工程实际综合比较不同防治方案，在降雨影响下，回填压脚至1/2坡高高度防治效果更好，边坡较稳定。Abstract: This paper presents an analysis of the hydraulic model of the slope instability of a down-dipping soft sandwich slope, focusing on the southern slope landslide project of Fushun West open Pit Mine. The study investigates the effects of groundwater and rainfall infiltration on the slope deformation evolution process using numerical simulation analysis with FLAC3D software. The sliding law of the slope with soft interlayer under the action of groundwater and rainfall infiltration is summarized. The results show that rainfall infiltration and groundwater flow produce osmotic pressure on the slope, causing the development of a large number of rupture surfaces on the slope. The maximum cumulative displacement is about 1.27 meters, resulting in a multi-stage landslide with a mixed landslide type. During the deformation and failure of the slope, tension failure is prone to occur along the weak layer near the slope top, providing a channel for surface water infiltration and groundwater migration, and showing the characteristics of multiple sliding surface, forming a continuous shear failure surface, which further leads to the multi-stage deformation of the slope. Under the influence of groundwater and rainfall infiltration, the water content in the weak layer of slope accumulates, resulting in damage and rupture, reducing the volume strain increment, lowering the effective stress, increasing the pore pressure, and reduing the shear strength, thereby inducing landslide. To improve the stability of the slope, the study compares different prevention and control schemes, including backfilling presser foot with different slope heights. The study finds that compared with the rainfall condition, the slope protected by backfilling presser foot with different slope heights has a higher safety factor. Considering the engineering practice, the backfilling and pressure protection up to half of the slope height has a better effect on preventing and controlling the slope, and the slope is more stable.
-
Key words:
- groundwater and rainfall infiltration /
- weak interlayer /
- FLAC3D /
- numerical simulation /
- stress
-
图 1 抚顺西露天矿南帮工程地质剖面图
Figure 1. Geological cross-section of the southern slope of Fushun West open Pit Mine
图 2 抚顺西露天矿南帮地裂缝
Figure 2. Site photo of ground cracks on the southern slope of Fushun West open Pit Mine
图 3 南帮滑坡形成机制模型
Figure 3. Model of formation mechanism of the southern slope of Fushun West open Pit Mine
图 5 坡体随循环步长增加的合位移变化情况（单位：m）
Figure 5. The variation of the cumulative displacement of the slope with increasing cycle steps （unit: m）
图 6 坡体随循环步长增加发展的塑性区变化情况
Figure 6. Changes in the plastic zone developed by the slope with increasing cycle step
图 8 监测点体积应变增量随时间的发展演化情况
Figure 8. Evolution of the development of volumetric strain increments over time at monitoring points
图 9 监测点x向有效应力随时间的发展演化情况
Figure 9. Evolution of the development of the effective stress in the x-direction over time at monitoring points
地层岩性 密度/（kg/m3） 弹性模量/（GPa） 泊松比 粘聚力/（MPa） 抗拉强度/（MPa） 内摩擦角/° 渗透系数/（m2/Pa/s） 凝灰岩 2590 10 0.24 3 2 45 9e-10 凝灰岩（弱化） 2590 1 0.24 0.3 0.2 40 9e-10 玄武岩 2800 25 0.23 3 2 40 9e-10 玄武岩（弱化） 2800 2.5 0.23 0.3 0.2 35 9e-10 煤 1400 1.2 0.24 0.45 0.15 30 9e-10 煤（弱化） 1400 1.2 0.24 0.45 0.24 35 3e-9 弱层 2100 15 0.24 2.5 1.75 48 9e-10 弱层（弱化） 2100 0.018 0.4 0.003 0.01 10 9e-10 花岗片麻岩 2800 35 0.22 4 3 45 8e-9 回填土 1860 0.27 0.3 0.2 0.1 25 9e-10 回填土（弱化） 1860 0.027 0.3 0.02 0.01 20 9e-10 断层泥 1800 0.01 0.4 0.18 0.2 7 3e-9 油页岩 2550 5 0.22 0.15 0.35 35 9e-10 
下载: 导出CSV
表 2 边坡防治方案稳定性评价结果
Table 2. Stability evaluation results of slope control scheme
工况 防治方案剖面图 边坡合位移变化云图 安全系数 稳定性分析 现状 
1.22 稳定 降雨 
0.71 不稳定 回填1/10
坡高
0.89 不稳定 回填1/5
坡高
0.96 不稳定 回填1/4
坡高
1.02 欠稳定 回填1/3
坡高
1.08 欠稳定 回填1/2
坡高
1.15 稳定 回填3/5
坡高
1.21 稳定 回填2/3
坡高
1.42 稳定 回填3/4
坡高
1.36 稳定
下载: 导出CSV
-
[1] 李安洪, 周德培, 冯君. 顺层岩质边坡稳定性分析与支挡防护设计[M]. 北京: 人民交通出版社, 2011LI Anhong, ZHOU Depei, FENG Jun. Stability analysis and retaining protection design of bedding rock slope[M]. Beijing: China Communications Press, 2011. （in Chinese with English abstract） [2] 蒋先念,张晨阳. 三峡库区典型顺斜向岩质滑坡变形破坏特征及失稳机制分析[J]. 中国地质灾害与防治学报,2021,32(2):36 − 42. [JIANG Xiannian,ZHANG Chenyang. Deformation characteristics and failure mechanism of large-scale obliquely dip rock landslide in the Three Gorges Reservoir Region[J]. The Chinese Journal of Geological Hazard and Control,2021,32(2):36 − 42. (in Chinese with English abstract) [3] 李守定,李晓,吴疆,等. 大型基岩顺层滑坡滑带形成演化过程与模式[J]. 岩石力学与工程学报,2007,26(12):2473 − 2480. [LI Shouding,LI Xiao,WU Jiang,et al. Evolution process and pattern of sliding zone in large consequent bedding rock landslide[J]. Chinese Journal of Rock Mechanics and Engineering,2007,26(12):2473 − 2480. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-6915.2007.12.012 [4] 张璟,陈文胜,蒋茂林. 等厚顺层岩质边坡稳定性的模型试验研究及数值验证[J]. 北方交通,2020(10):40 − 44. [ZHANG Jing,CHEN Wensheng,JIANG Maolin. Model test study and numerical verification of stability of bedding rock slope with equal thickness[J]. Northern Communications,2020(10):40 − 44. (in Chinese) [5] 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) [6] 陈林万,张晓超,裴向军,等. 降雨诱发直线型黄土填方边坡失稳模型试验[J]. 水文地质工程地质,2021,48(6):151 − 160. [CHEN Linwan,ZHANG Xiaochao,PEI Xiangjun,et al. Model test of the linear loess fill slope instability induced by rainfall[J]. Hydrogeology & Engineering Geology,2021,48(6):151 − 160. (in Chinese with English abstract) doi: 10.16030/j.cnki.issn.1000-3665.202010041 [7] 王智德,夏元友,夏国邦,等. 顺层岩质边坡稳定性极限分析上限法[J]. 岩土力学,2015,36(2):576 − 583. [WANG Zhide,XIA Yuanyou,XIA Guobang,et al. Upper bound limit analysis method for stability analysis of bedding rock slopes[J]. Rock and Soil Mechanics,2015,36(2):576 − 583. (in Chinese with English abstract) [8] 冯君,周德培,李安洪. 顺层岩质边坡开挖稳定性研究[J]. 岩石力学与工程学报,2005,24(9):1474 − 1478. [FENG Jun,ZHOU Depei,LI Anhong. Research on stability of rock bedded slopes[J]. Chinese Journal of Rock Mechanics and Engineering,2005,24(9):1474 − 1478. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-6915.2005.09.003 [9] 陈从新,黄平路,卢增木. 岩层倾角影响顺层岩石边坡稳定性的模型试验研究[J]. 岩土力学,2007,28(3):476 − 481. [CHEN Congxin,HUANG Pinglu,LU Zengmu. Study on correlation between stability of consequent rock slope and obliquity of rock layer by simulation experiment[J]. Rock and Soil Mechanics,2007,28(3):476 − 481. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-7598.2007.03.009 [10] HART M W. Bedding-parallel shear zones as landslide mechanisms in horizontal sedimentary rocks[J]. Environmental and Engineering Geoscience,2000,6(2):95 − 113. doi: 10.2113/gseegeosci.6.2.95 [11] 舒继森,唐震,才庆祥. 水力学作用下顺层岩质边坡稳定性研究[J]. 中国矿业大学学报,2012,41(4):521 − 525. [SHU Jisen,TANG Zhen,CAI Qingxiang. Research on stability of bedding rock slopes under hydraulic pressure[J]. Journal of China University of Mining & Technology,2012,41(4):521 − 525. (in Chinese with English abstract) [12] 魏刚,殷志强,罗银飞,等. 黄河上游康杨滑坡堆积体特征及形成机理分析[J]. 中国地质灾害与防治学报,2022,33(2):1 − 8. [WEI Gang,YIN Zhiqiang,LUO Yinfei,et al. Analysis on the accumulation deposits characteristics and formation mechanism of Kangyang landslide in the upper reaches of Yellow River[J]. The Chinese Journal of Geological Hazard and Control,2022,33(2):1 − 8. (in Chinese with English abstract) doi: 10.16031/j.cnki.issn.1003-8035.2022.02-01 [13] HOEK E, BRAY J. Rock slope engineering, 3rd ed[M]. London: [s.n.], 1981. [14] 赵磊,付昱凯,陈春利,等. 青川浅层滑坡降雨入渗及稳定性研究[J]. 干旱区资源与环境,2022,36(1):111 − 119. [ZHAO Lei,FU Yukai,CHEN Chunli,et al. Study on rainfall infiltration and stability of Qingchuan shallow landslide[J]. Journal of Arid Land Resources and Environment,2022,36(1):111 − 119. (in Chinese) doi: 10.13448/j.cnki.jalre.2022.015 [15] 聂永鹏,倪万魁,刘魁,等. 陕西延安某老滑坡场地上建筑物破坏机理分析[J]. 中国地质灾害与防治学报,2019,30(2):43 − 50. [NIE Yongpeng,NI Wankui,LIU Kui,et al. Damage mechanism of buildings on an old landslide in Yan’an City[J]. The Chinese Journal of Geological Hazard and Control,2019,30(2):43 − 50. (in Chinese with English abstract) doi: 10.16031/j.cnki.issn.1003-8035.2019.02.06 [16] 田辽西,赵玉苹,赵伟. 降雨入渗对某滑坡地下水渗流及滑坡稳定性影响[J]. 科学技术创新,2022(20):125 − 128. [TIAN Liaoxi,ZHAO Yuping,ZHAO Wei. Influence of rainfall infiltration on groundwater seepage and landslide stability of a landslide[J]. Scientific and Technological Innovation,2022(20):125 − 128. (in Chinese with English abstract) doi: 10.3969/j.issn.1673-1328.2022.20.032 [17] 刘艳辉,刘丽楠. 基于诱发机理的降雨型滑坡预警研究—以花岗岩风化壳二元结构斜坡为例[J]. 工程地质学报,2016,24(4):542 − 549. [LIU Yanhui,LIU Linan. Rainfall-induced mechanism based early warning model for slopes of dualistic layers in weathered granitic area[J]. Journal of Engineering Geology,2016,24(4):542 − 549. (in Chinese with English abstract) [18] RICHARDS L A. Capillary conduction of liquids through porous mediums[J]. Physics,1931,1(5):318 − 333. doi: 10.1063/1.1745010 [19] FREDLUND D G,XING A Q. Equations for the soil-water characteristic curve[J]. Canadian Geotechnical Journal,1994,31(4):521 − 532. doi: 10.1139/t94-061 [20] 黄润秋,徐则民,许模. 地下水的致灾效应及异常地下水流诱发地质灾害[J]. 地球与环境,2005,33(3):1 − 9. [HUANG Runqiu,XU Zemin,XU Mo. Hazardous effects of underground water and extraordinary water flow-induced geohazards[J]. Geology-geochemistry,2005,33(3):1 − 9. (in Chinese with English abstract) doi: 10.3969/j.issn.1672-9250.2005.03.001 [21] 郭子钰,刘向峰,王来贵,等. 抚顺西露天矿开挖作用下边坡变形破坏滑动规律研究[J]. 金属矿山,2021(12):190 − 199. [GUO Ziyu,LIU Xiangfeng,WANG Laigui,et al. Study on the slope deformation and failure sliding law under the excavation of Fushun west open-pit mine[J]. Metal Mine,2021(12):190 − 199. (in Chinese with English abstract) [22] 郭子钰. 露天煤矿边坡变形破坏滑动全过程研究[D]. 阜新: 辽宁工程技术大学GUO Ziyu. Study on the whole process of slope deformation, failure and sliding in open-pit coal mine[D]. Fuxin: Liaoning Technical University. （in Chinese with English abstract） [23] 缪海宾. 抚顺西露天矿高陡边坡蠕变-大变形综合预警及防治技术研究[D]. 阜新: 辽宁工程技术大学,MIAO Haibin. Research on comprehensive early warning and prevention technology of creep-large deformation in high and steep slope of Fushun west open-pit mine[D]. Fuxin: Liaoning Technical University, . （in Chinese with English abstract） [24] 崔原. 抚顺西露天矿南帮滑坡地质特征与机理分析[D]. 长春: 吉林大学CUI Yuan. Geological characteristics and mechanism analysis of south slope landslide in Fushun west open pit mine[D]. Changchun: Jilin University. （in Chinese with English abstract） [25] 李超. 抚顺西露天矿南帮边坡稳定性分析[D]. 阜新: 辽宁工程技术大学LI Chao. Stability analysis of south slope of Fushun west open pit mine[D]. Fuxin: Liaoning Technical University. （in Chinese with English abstract） [26] 郭富赟,周小龙,火飞飙,等. 舟曲断裂带滑坡灾害效应与防治对策研究[J]. 中国地质灾害与防治学报,2022,33(6):80 − 89. [GUO Fuyun,ZHOU Xiaolong,HUO Feibiao,et al. Study on landslide disaster effect and prevention countermeasures in Zhouqu fault zone[J]. The Chinese Journal of Geological Hazard and Control,2022,33(6):80 − 89. (in Chinese) -
下载:
点击查看大图
图(9) / 表(2)
计量
- 文章访问数: 700
- HTML全文浏览量: 2277
- PDF下载量: 131
- 被引次数: 0
邮件订阅
RSS