川东巴州区滑坡发育规律及危险性预测评价

发布时间：2018-10-10 18:31

【摘要】：研究区位于四川盆地东北部,大巴山南麓,达州西部,处于红层低中山丘陵区,为四川省划定的地质灾害易发区。巴州区滑坡不仅对耕地、经济林、公路及铁路造成威胁,更主要的是严重威胁到村民的生命安全。据不完全统计,巴州区每年因滑坡造成的经济财产损失成百上千万。因此,研究该区滑坡的发育规律及形成机制,并对滑坡进行危险性预测评价,对滑坡地质灾害的防灾减灾、工程安全及环境保护具有实际意义。本文在对研究区地质背景条件及滑坡灾害点详细调查研究的基础上,通过分析巴州区滑坡发育特征及典型滑坡特征,分析研究滑坡的发育规律及形成机制。对研究区滑坡空间分布的变维分形特征及评价因子单因素敏感性进行了分析,将传统的半定量层次分析法转化为全定量,最终采用综合指数法对研究区滑坡危险性进行了预测评价。取得如下主要研究成果:(1)巴州区位于川东低中山丘陵区,谷岭纵横,地势北高南低,从北向南由中山逐渐过渡为低山和丘陵地形;主要出露侏罗系上统蓬莱镇组、白垩系下统苍溪组和白龙组地层,岩性均为砂泥岩互层;断层不发育,主要发育4条宽缓褶皱。(2)对研究区的72个滑坡进行特征分析,25个土质滑坡,47个岩质滑坡,5个大型滑坡,14个中型滑坡,53个小型滑坡。以余家碥滑坡、吴志勇坝2号滑坡、陈家院滑坡作为典型滑,详细分析了滑坡的发育特征。(3)对滑坡的空间分布进行详细统计分析,得出滑坡的发育规律:滑坡发育的主要地貌部位为构造侵蚀低中山地貌(单面山),地层岩性为侏罗系蓬莱镇组泥岩夹砂岩及白垩系白龙组砂岩夹泥岩,坡体结构为缓倾顺向坡,坡度为10°~30°,高程为510m~1110m,降雨量大于1300mm。对研究区滑坡的变形破模式进行研究,得出该区滑坡的变形破坏模式有3种:蠕滑-拉裂、滑移-拉裂、平推式,并进行了形成机制的分析。(4)在滑坡发育规律的基础上,综合选取了地貌部位、地层岩性、坡体结构、坡度、高程、降雨量、地震及人类工程活动作为评价因子。对滑坡评价因子做了敏感性分析(发育密度),并对滑坡空间分布的变维分形特征进行研究,得出各评价因子的分维值分别为:坡体结构(1.792)、坡度(1.482)、高程(1.082)、地层岩性(0.863)、降雨量(0.273)、地貌(0.219)、人类工程活动(0.241)、地震(0.1)。(5)结合分维值,采用层次分析法全定量确定评价因子权重分别为:坡体结构(0.330)、坡度(0.237)、高程(0.165)、地层岩性(0.121)、降雨量(0.050)、地貌(0.039)、人类工程活动(0.039)、地震(0.019)。利用ARCGIS对评价因子的量化指标进行栅格叠加,得到综合指数F(0.061~0.992),根据界限阀值把研究区分为:极高危险区、高等危险区、中等危险区、低危险区域。预测结果与野外调查结果相吻合,证明本次预测评价是合理的。
[Abstract]:The study area is located in the northeast of Sichuan Basin, the southern foot of Daba Mountain, and the west of Dazhou. The landslide in Bazhou not only threatens cultivated land, economic forest, highway and railway, but also seriously threatens the safety of villagers. According to incomplete statistics, Bazhou District caused by landslides each year caused millions of economic property losses. Therefore, it is of practical significance to study the development law and formation mechanism of landslide in this area, and to predict and evaluate the risk of landslide, which is of practical significance for the prevention and mitigation of landslide geological disasters, engineering safety and environmental protection. On the basis of the detailed investigation of geological background conditions and landslide disaster sites in the study area, the development law and formation mechanism of landslide are analyzed by analyzing the characteristics of landslide development and typical landslide in Bazhou district. The fractal characteristics of landslide spatial distribution and the single factor sensitivity of evaluation factors are analyzed, and the traditional semi-quantitative analytic hierarchy process (AHP) is transformed into full quantification. Finally, the comprehensive index method is used to predict and evaluate the landslide hazard in the study area. The main research results are as follows: (1) Bazhou district is located in the middle and low hilly area of East Sichuan, with the valley lying vertically and horizontally, the terrain is high in the north and low in the south, and gradually transition from the north to the south to the low mountain and hilly terrain, the main body is the Penglai Zhen formation of the Upper Jurassic. The strata of Cretaceous Cangxi formation and Bailong formation are composed of sand and mudstone interbedded, and faults are not developed. There are mainly 4 broad and slow folds. (2) the characteristics of 72 landslides in the study area were analyzed, 25 soil landslides, 47 rock landslides, 5 large landslides, 14 medium landslides and 53 small landslides. Taking Yujiabian landslide, Wu Zhiyongba No. 2 landslide and Chen Jiayuan landslide as typical landslide, the development characteristics of landslide are analyzed in detail. (3) the spatial distribution of landslide is analyzed in detail. The development law of landslide is obtained: the main landform of landslide development is structural erosion low middle mountain landform (single side mountain), stratigraphic lithology is mudstone intercalated sandstone of Jurassic Penglai Zhen formation and sandstone of Cretaceous Bailong formation, slope body structure is gently inclined downhill slope. The slope is 10 掳~ 30 掳, the elevation is 510mg, the rainfall is more than 1300mm. This paper studies the deformation and failure mode of landslide in the study area, and concludes that there are three kinds of deformation and failure modes of landslide in this area: creep-pull crack, slip-pull crack, flat push mode, and the forming mechanism is analyzed. (4) on the basis of the development law of landslide, it is found that there are three kinds of deformation and failure modes of landslide in this area. The geomorphological position, stratigraphic lithology, slope structure, slope, elevation, rainfall, earthquake and human engineering activity were selected as evaluation factors. The sensitivity analysis (developmental density) of landslide evaluation factor is made, and the fractal characteristics of the spatial distribution of landslide are studied. The fractal dimensions of the evaluation factors are obtained as follows: slope structure (1.792), slope (1.482), elevation (1.082), stratigraphic lithology (0.863), rainfall (0.273), geomorphology (0.219), human engineering activities (0.241), earthquake (0.1). (5) combined with fractal dimension. The weight of evaluation factors determined by AHP is: slope structure (0.330), slope (0.237), elevation (0.165), stratigraphic lithology (0.121), rainfall (0.050), geomorphology (0.039), human engineering activity (0.039), earthquake (0.019). The quantitative index of evaluation factor was superposed by ARCGIS, and the comprehensive index F (0.061 ~ 0.992) was obtained. According to the threshold, the study was divided into very high risk area, middle risk area and low risk area. The prediction results are in agreement with the field investigation results, which proves that this prediction evaluation is reasonable.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.22

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