摘要
岷江河谷地处龙门山强震区,近年来发生了大量倾倒变形引发的滑坡等链式灾害,造成了重大伤亡。为了分析岷江河谷深层倾倒演化特征和灾害链效应,以仅距茂县新磨村滑坡10 km的梯子槽高位特大型倾倒为例,采用地质测绘、钻探、物探、井探、监测、室内试验、数值模拟等多手段,探明了倾倒基本特征,分析了倾倒的成因机制,研究了灾害链效应。结果表明:①梯子槽倾倒规模达1388.2×10^(4)m^(3),倾倒结构复杂,其中倾倒上部为粉质黏土夹碎块石、下部为碎裂岩块,滑带为粉质黏土夹角砾,平均厚度4.5 m,最大可达10 m,擦痕清晰可见;②倾倒变形剧烈,坡体上裂缝随处可见,后缘贯通裂缝长约750 m,下错高度5~10 m;③倾倒经历了五个变形阶段,主要是反倾层状岩体倾倒折断,折断带风化成“土”,在后期降雨及地震作用下发生失稳破坏;④倾倒一旦失稳将堵塞岷江造成灾害链,据溃坝洪水灾害链演进预测分析:洪水将会淹没金龙潭水电站、两河口、飞虹乡以及沟口镇,淹没及影响G213国道20.2 km,总危害资产4.5亿,但对茂县县城影响较小。
Minjiang River Valley is located in Longmenshan strong earthquake area. In recent years, a large number of chain disasters such as landslides caused by dumping deformation have occurred, resulting in heavy casualties. In order to analyze the evolution characteristics of deep dumping and disaster chain effect in Minjiang River Valley, taking the high-level super large dumping of Ti zicao only 10 km away from Xinmo village landslide in Mao County as an example. By means of geological mapping, drilling, geophysical exploration, well exploration, monitoring, laboratory test and numerical simulation, the basic characteristics of landslide were proved, the formation mechanism of landslide was analyzed, and the chain effect of disaster was studied. The results show these as follows. The scale of ladder trough landslide is 1 388.2×10^(4) m^(3), and the landslide structure is complex. The upper part of the slide body is silty clay mixed with fragments, and the lower part is fragmentary rock. The slide zone is silty clay mixed with breccias, with an average thickness of 4.5 m and a maximum of 10 m, and the rub marks are clearly visible. The landslide deformation is severe, and cracks can be seen everywhere on the slope body. The length of the through-through crack at the rear edge is about 750 m, and the height of the fault is 5~10 m. The landslide experiences five deformation stages, mainly the dumping and breaking of antidumping stratified rock mass. The fracture zone weathers into “soil”, and the instability failure occurres under the action of rainfall and earthquake in the later period. Once the landslide is unstable, it will block the Minjiang River and cause the disaster chain. According to the prediction analysis of the evolution of the dam-break flood disaster chain, the flood will inunge Jinlongtan Hydropower Station, Lianghekou, Feihong Township and Goukou Town, and will inunge and affect 20.2 km of G213 national Road, with the total damage assets of 450 million yuan, but the impact on Maoxian county is sma
作者
蒙明辉
崔圣华
张文
刘康林
杨学之
覃亮
蒋涛
MENG Ming-hui;CUI Sheng-hua;ZHANG Wen;LIU Kang-lin;YANG Xue-zhi;QIN Liang;JIANG Tao(Sichuan Hua Di Building Engineering Co.,Ltd.,Chengdu 610081,China;Sichuan Engineering Technology Research Center of Geohazard Prevention,Chengdu 610081,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China;Institute of Exploration Technology,CAGS,Chengdu 611734,China)
出处
《科学技术与工程》
北大核心
2022年第27期11829-11841,共13页
Science Technology and Engineering
基金
国家重点研发计划(2018YFC1505400)
西藏自治区地质灾害防治技术研究与示范项目(藏财采【2020】0890-1)
国家自然科学基金青年科学基金(41907254)
地质灾害防治与地质环境保护国家重点实验室项目(SKLGP2021Z014)。
关键词
高位倾倒
倾倒变形
成因机制
堵江
灾害链效应
high landslide
toppling deformation
genetic mechanism
blocking river
chain effect of disaster
