【摘要】：研究區(qū)位于四川盆地東北部,大巴山南麓,達州西部,處于紅層低中山丘陵區(qū),為四川省劃定的地質災害易發(fā)區(qū)。巴州區(qū)滑坡不僅對耕地、經濟林、公路及鐵路造成威脅,更主要的是嚴重威脅到村民的生命安全。據不完全統計,巴州區(qū)每年因滑坡造成的經濟財產損失成百上千萬。因此,研究該區(qū)滑坡的發(fā)育規(guī)律及形成機制,并對滑坡進行危險性預測評價,對滑坡地質災害的防災減災、工程安全及環(huán)境保護具有實際意義。本文在對研究區(qū)地質背景條件及滑坡災害點詳細調查研究的基礎上,通過分析巴州區(qū)滑坡發(fā)育特征及典型滑坡特征,分析研究滑坡的發(fā)育規(guī)律及形成機制。對研究區(qū)滑坡空間分布的變維分形特征及評價因子單因素敏感性進行了分析,將傳統的半定量層次分析法轉化為全定量,最終采用綜合指數法對研究區(qū)滑坡危險性進行了預測評價。取得如下主要研究成果:(1)巴州區(qū)位于川東低中山丘陵區(qū),谷嶺縱橫,地勢北高南低,從北向南由中山逐漸過渡為低山和丘陵地形;主要出露侏羅系上統蓬萊鎮(zhèn)組、白堊系下統蒼溪組和白龍組地層,巖性均為砂泥巖互層;斷層不發(fā)育,主要發(fā)育4條寬緩褶皺。(2)對研究區(qū)的72個滑坡進行特征分析,25個土質滑坡,47個巖質滑坡,5個大型滑坡,14個中型滑坡,53個小型滑坡。以余家碥滑坡、吳志勇壩2號滑坡、陳家院滑坡作為典型滑,詳細分析了滑坡的發(fā)育特征。(3)對滑坡的空間分布進行詳細統計分析,得出滑坡的發(fā)育規(guī)律:滑坡發(fā)育的主要地貌部位為構造侵蝕低中山地貌(單面山),地層巖性為侏羅系蓬萊鎮(zhèn)組泥巖夾砂巖及白堊系白龍組砂巖夾泥巖,坡體結構為緩傾順向坡,坡度為10°~30°,高程為510m~1110m,降雨量大于1300mm。對研究區(qū)滑坡的變形破模式進行研究,得出該區(qū)滑坡的變形破壞模式有3種:蠕滑-拉裂、滑移-拉裂、平推式,并進行了形成機制的分析。(4)在滑坡發(fā)育規(guī)律的基礎上,綜合選取了地貌部位、地層巖性、坡體結構、坡度、高程、降雨量、地震及人類工程活動作為評價因子。對滑坡評價因子做了敏感性分析(發(fā)育密度),并對滑坡空間分布的變維分形特征進行研究,得出各評價因子的分維值分別為:坡體結構(1.792)、坡度(1.482)、高程(1.082)、地層巖性(0.863)、降雨量(0.273)、地貌(0.219)、人類工程活動(0.241)、地震(0.1)。(5)結合分維值,采用層次分析法全定量確定評價因子權重分別為:坡體結構(0.330)、坡度(0.237)、高程(0.165)、地層巖性(0.121)、降雨量(0.050)、地貌(0.039)、人類工程活動(0.039)、地震(0.019)。利用ARCGIS對評價因子的量化指標進行柵格疊加,得到綜合指數F(0.061~0.992),根據界限閥值把研究區(qū)分為:極高危險區(qū)、高等危險區(qū)、中等危險區(qū)、低危險區(qū)域。預測結果與野外調查結果相吻合,證明本次預測評價是合理的。
[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 擄~ 30 擄, 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.
【學位授予單位】：成都理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：P642.22

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本文編號：2262808