Deformation characteristics and genetic mechanism of a new landslide at K52 of Luyang freeway
-
摘要:
阳鹿（阳朔—鹿寨）高速公路K52新滑坡为古滑坡堆积体中局部复活的滑坡，处于急剧变形状态，需进行抢险性处治。复工后对该滑坡进行了详细的地质勘察及变形监测，借助FLAC3D软件对其成因、变形过程及变形机理进行了研究，得到了以下结论：（1）古滑坡堆积体形成于顺层岩质滑坡，堆积体内部发育软-可塑状软弱夹层风化页岩，为新滑坡的主要滑带土；（2）导致新滑坡变形的主要内因为不良地质、微地貌、特殊的岩土结构，主要外因为在中后部堆载、填土改变地表水径流路径、向滑坡排放生活用水及降雨；（3）新滑坡具有三层滑面，失稳前底部滑面为主滑面，失稳阶段中部滑面为主滑面，属前段推移后段牵引型复合式滑坡，具多级、逐级及渐进滑动特点；（4）新滑坡变形进程为：后缘拉张变形-中部剪切蠕变-滑体A、B推移剪出失稳-滑体C前缘临空牵引失稳；（5）新滑坡处治重点应防止顶部、中部及底部三个滑动面继续变形，也应防止古滑面及古滑坡堆积体内部其余风化页岩夹层产生次级滑动。
Abstract:The new landslide at K52 Luyang freeway is a new-reactivated landslide, which is in the accumulation of the giant landslides formed in ancient time. This landslide is in a state of rapid deformation, which requires the emergent treatment immediately. Many steps including geological survey, drilling, in-situ test, laboratory test, and deformation monitoring are applied to analysis this giant landslide after the resumption of construction, where the characteristics of geomorphology, stratum structure, sliding surface, sliding mass, sliding bed, deformation, and hydrogeology of the landslide were identified. By using FLAC3D software, several aspects containing the cause of this sliding and deformation mechanism were analyzed, The following conclusions were given after the functional investigation: (1) The giant ancient landslide accumulation was formed by deep rock landslide. Soft plastic weak intercalated weathered shale is developed in the accumulation body, which is the main sliding zone soil of the new landslide; (2) The main internal causes of the new landslide were unfavorable geology, micro landform, and the special geotechnical structure, while the main external causes were artificial loading on the middle and back part of the accumulation of the ancient landslide and rainfall; (3) There were three sliding surfaces, the lowest surface was the main sliding surface at the creep stage, the mddle surface was the main sliding surface at the unstable stage, and this sliding could be classified as the composite sliding of pushing from the front section and dragging by the back section, which had the features of multiply-stage, progressively gradual failure; (4) The deformation process of this new landslide was: firstly, there was a tensile deformation in the back part of the initial landslide and a shear creep in the middle. Then, the sliding A and B lost stability due to shear failure in the front edge, and the sliding C failed caused by the tensile force due to the lost support in the front edge; (5) The key point of new landslide treatment is to prevent the deformation of the top, mddle and lowest sliding surfaces, and to prevent the secondary sliding of the ancient sliding surface and other weathered shale Intercalations in the ancient landslide accumulation, which may be used as an acceptable reference for the uses of research and design by the similar engineering fields.
-
Key words:
- landslide /
- deformation mechanism /
- numerical simulation /
- freeway /
- stability /
- deformation monitoring
-
-
表 1 新滑坡结构特征
Table 1. Structural characteristics of new landslide
滑体区域 滑体特征 滑面特征 滑床特征 A区 上部为第四系松散人工填土，为本区主要
组成部分，下部少量为古滑坡堆积体顶部滑面，上陡下缓状，滑面由两部分组成，上部分位于人工填土内部，下部分滑面位于古滑坡堆积体内部，见图1右上照片，滑带土主要由风化页岩组成，呈土柱状，可塑状，滑带厚0.4～2.5 m 由两部分组成：上部分为人工填土；
下部分为古滑坡堆积体A+B区 由古滑坡堆积体及第四系人工填土组成，
两者含量相当中部滑面，上陡下缓状，滑面由两部分组成，上部分位于人工填土内部，下部分滑面位于古滑坡堆积体内部，见图1右中照片，滑带土主要由风化页岩组成，呈土柱状，软～可塑状，滑带厚0.4～2.0 m 由两部分组成：上部分为人工填土；
下部分为古滑坡堆积体C区 主要由古滑坡堆积体组成，上部为少量
第四系人工填土底部滑面，滑面陡倾状，由两部分组成，上部分位于残坡积层与堆积体交界面，下部分位于堆积体内部，滑
带土上部分为粉质黏土，可塑状，下部分为风化页岩，软～可塑状，滑带厚0.2～2.0 m由两部分组成：上部分为残坡积层，
下部分为古滑坡堆积体
下载: 导出CSV
表 2 新滑坡地表主要裂缝特征
Table 2. Characteristics of surface cracks in new landslides
裂缝编号 裂缝位置 裂缝类型 裂缝特征 发现时间 L1～L2 C区后缘 拉张裂缝 呈弧形，宽0.1～0.2 m，延伸50～100 m，可见深度0.2～1.2 m，裂缝前后下错台阶高度约0.2 m 2019年5—6月 L3～L5 C区两侧 拉张剪切裂缝 缝宽0.05～0.1 m，延伸10～30 m，呈小弧度变形，为拉张及剪切综合成因，裂缝两侧可见水平向错动 2019年5—6月 L6～L7 A区后缘 拉张裂缝 呈圈椅状分布，中轴线与滑动轴近重合，裂缝宽度约0.1～0.2 m，最大可视深度0.5 m，延伸长度约100～250 m，最大错台落差约0.8 m。裂缝有进一步贯通的趋势，是本滑坡裂缝发育最为活跃的地带，沉降变形明显 2018年7月至2019年6月
裂缝持续增加L8～L9 A区西侧
B区东侧剪切裂缝 近直线型，缝宽0.02～0.1 m，延伸10～50 m，为剪切成因，裂缝两侧可见相对错动 2019年1—4月 L10～L12 A区前缘 鼓胀裂缝 形状多样，为剪出口，与等高线近平行，缝宽0.1～0.3 m，延伸长度10～
25 m，局部裂缝见地下水冒出2019年1—4月 L13～L14 B区前缘 鼓胀裂缝 近直线，裂缝高程与等高线近重叠，为剪出口，缝宽0.1～0.3 m，延伸长度20～50 m，局部见少量地下水冒出 2019年1—4月
下载: 导出CSV
表 3 岩土体物理力学参数
Table 3. Physical and mechanical parameters of rock and soil
名称 重度/ (kN·m−3) 弹性模量/ MPa 泊松比 黏聚力/ kPa 内摩擦角/ (°) 天然 饱和 天然 饱和 天然 饱和 人工填土 19.4 20.0 55 0.30 22 18 30 23 古滑坡堆积体 20.2 21.0 85 0.28 30 25 27 23 滑面 19.6 20.4 5.60 0.35 25 20 20 16 淤泥质黏土 18.5 19.0 1.50 0.42 15 12 9 7 残坡积层 19.0 19.8 100.00 0.26 35 30 28 23 基岩 26.5 27.0 11500.00 0.23 150 100 45 40
下载: 导出CSV
-
[1] 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)
[2] 史文兵, 黄润秋, 左双英, 等. 贵州省贵定县定东小学滑坡形成机制[J]. 水土保持通报,2015,35(1):287 − 290. [SHI Wenbing, HUANG Runqiu, ZUO Shuangying, et al. Landslide formation mechanism at Dingdong primary school of Guiding County in Guizhou Province[J]. Bulletin of Soil and Water Conservation,2015,35(1):287 − 290. (in Chinese with English abstract)
[3] 张岩岩, 文海家, 麻超超, 等. 基于多源数据的蔡家坝特大型滑坡成因机制研究及稳定性评价[J]. 岩石力学与工程学报,2018,37(9):2048 − 2063. [ZHANG Yanyan, WEN Haijia, MA Chaochao, et al. Failure mechanism and stability analysis of huge landslide of Caijiaba based on multi-source data[J]. Chinese Journal of Rock Mechanics and Engineering,2018,37(9):2048 − 2063. (in Chinese with English abstract)
[4] 闫国强, 殷跃平, 黄波林, 等. 三峡库区巫山金鸡岭滑坡成因机制与变形特征[J]. 岩土力学,2019,40(增刊 1):329 − 340. [YAN Guoqiang, YIN Yueping, HUANG Bolin, et al. Formation mechanism and deformation characteristics of Jinjiling landslide in Wushan, Three Gorges Reservoir region[J]. Rock and Soil Mechanics,2019,40(Sup 1):329 − 340. (in Chinese with English abstract)
[5] 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)
[6] 中华人民共和国交通运输部. 公路滑坡防治设计规范: GTG/T 3334-2018[S]. 北京: 人民交通出版社股份有限公司, 2019.
Ministry of Transport of the People's Republic of China. Specifications for design of highway landslide stabilization: GTG/T 3334-2018 [S]. Beijing: China Communications Press Co. Ltd., 2019. (in Chinese)
[7] 张卫雄, 翟向华, 丁保艳, 等. 甘肃舟曲江顶崖滑坡成因分析与综合治理措施[J]. 中国地质灾害与防治学报,2020,31(5):7 − 14. [ZHANG Weixiong, ZHAI Xianghua, DING Baoyan, et al. Causative analysis and comprehensive treatment of the Jiangdingya landslide in Zhouqu County of Gansu Province[J]. The Chinese Journal of Geological Hazard and Control,2020,31(5):7 − 14. (in Chinese with English abstract)
[8] 窦晓东, 张泽林. 甘肃舟曲垭豁口滑坡复活机理及成因探讨[J]. 中国地质灾害与防治学报,2021,32(2):9 − 18. [DOU Xiaodong, ZHANG Zelin. Mechanism and causal analysis on the Yahuokou landslide reactivation and causes(Zhouqu County, Gansu, China)[J]. The Chinese Journal of Geological Hazard and Control,2021,32(2):9 − 18. (in Chinese with English abstract)
[9] 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)
[10] 代贞伟, 殷跃平, 魏云杰, 等. 三峡库区藕塘滑坡特征、成因及形成机制研究[J]. 水文地质工程地质,2015,42(6):145 − 153. [DAI Zhenwei, YIN Yueping, WEI Yunjie, et al. Characteristics, origin and formation mechanism of the Outang landslide in the Three Gorges Reservoir area[J]. Hydrogeology & Engineering Geology,2015,42(6):145 − 153. (in Chinese with English abstract)
[11] 吕俊磊, 胡卸文, 顾成壮, 等. 四川省南江县下两中学滑坡成因机制分析与稳定性评价[J]. 中国地质灾害与防治学报,2015,26(4):12 − 17. [LYU Junlei, HU Xiewen, GU Chengzhuang, et al. Formation mechanism and stability of landslide at Xialiang middle school in Nanjiang County, Sichuan[J]. The Chinese Journal of Geological Hazard and Control,2015,26(4):12 − 17. (in Chinese with English abstract)
[12] 易志坚, 黄润秋, 吴海燕, 等. 唐古栋滑坡成因机制研究[J]. 工程地质学报,2016,24(6):1072 − 1079. [YI Zhijian, HUANG Runqiu, WU Haiyan, et al. Research on formation mechanism of Tanggudong landslide[J]. Journal of Engineering Geology,2016,24(6):1072 − 1079. (in Chinese with English abstract)
[13] 张杰, 王宇, 李长才, 等. 云南彝良两河镇坪子滑坡成因及特征分析[J]. 水文地质工程地质,2018,45(6):157 − 163. [ZHANG Jie, WANG Yu, LI Changcai, et al. Characteristics and cause analyses of the Pingzi landslide in Lianghe Town, Yiliang County, Yunnan Province[J]. Hydrogeology & Engineering Geology,2018,45(6):157 − 163. (in Chinese with English abstract)
[14] 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)
[15] 蒋中明, 李小凡, 伍忠才. 悬挂型暂态饱和边坡稳定性分析方法研究[J]. 中国公路学报,2018,31(2):48 − 56. [JIANG Zhongming, LI Xiaofan, WU Zhongcai. Research on analysis method for stability of perched transient saturated slope[J]. China Journal of Highway and Transport,2018,31(2):48 − 56. (in Chinese with English abstract) doi: 10.3969/j.issn.1001-7372.2018.02.005
[16] 文海家, 张岩岩, 付红梅, 等. 降雨型滑坡失稳机理及稳定性评价方法研究进展[J]. 中国公路学报,2018,31(2):15 − 29. [WEN Haijia, ZHANG Yanyan, FU Hongmei, et al. Research status of instability mechanism of rainfall-induced landslide and stability evaluation methods[J]. China Journal of Highway and Transport,2018,31(2):15 − 29. (in Chinese with English abstract) doi: 10.3969/j.issn.1001-7372.2018.02.002
[17] 中华人民共和国交通运输部. 公路路基设计规范: JTG D30—2015[S]. 北京: 人民交通出版社, 2015.
Ministry of Transport of the People’s Republic of China. Specifications for design of highway subgrades: JTG D30—2015[S]. Beijing: China Communications Press, 2015. (in Chinese)
-
图(8)
表(3)
计量
- 文章访问数: 865
- PDF下载数: 13
- 施引文献: 0