【摘要】：我國的西北黃土地區(qū)具有非常特殊的地質(zhì)構(gòu)造背景，該區(qū)黃土滑坡災害頻發(fā)，且大部分處于高烈度地震區(qū)。本文以甘肅中南部地區(qū)為研究區(qū)，研究該區(qū)黃土滑坡所處的地質(zhì)環(huán)境和特征，通過大量的地質(zhì)調(diào)查、室內(nèi)試驗、理論計算和數(shù)值模擬等方法，對研究區(qū)黃土滑坡的特征、地震穩(wěn)定性和防治技術(shù)進行了系統(tǒng)的研究，取得了以下研究成果： 1、對研究區(qū)典型黃土滑坡的特征和形成機制進行了研究，結(jié)果表明，三家地滑坡為巨型黃土-泥巖老滑坡，坡體不良的地質(zhì)結(jié)構(gòu)和陳李溝泥石流對滑坡前緣的長期侵蝕是老滑坡形成的主要因素，“5.12”汶川地震誘發(fā)了滑坡前緣大規(guī)模復活滑動而后緣由于受前部滑動牽引而產(chǎn)生貫通裂縫，為牽引式滑坡。 2、針對典型黃土滑坡滑帶土的靜、動力性質(zhì)進行了直剪試驗、靜三軸和動三軸試驗，結(jié)果表明，九州和三家地滑坡滑帶土粘聚力與內(nèi)摩擦角的峰值和殘余值均隨含水量的增大而減�。换瑤羷訌椥阅Ａ侩S動應(yīng)變的增大而減小，阻尼比隨動應(yīng)變增大而緩慢增大,在很小范圍內(nèi)波動，動粘聚力和動內(nèi)摩擦角隨含水量的增大而減小。 3、考慮5類16項影響因素指標，建立了地震作用下黃土滑坡穩(wěn)定性模糊綜合評價模型，，基于巖土力學參數(shù)和地震加速度的隨機性和模糊性，提出了地震作用下黃土滑坡穩(wěn)定性的可靠度與模糊隨機可靠度計算方法，將建立的模型應(yīng)用到汶川震區(qū)三家地滑坡的地震穩(wěn)定性分析中，并利用擬靜力法對地震工況下滑坡的穩(wěn)定系數(shù)進行了計算。這幾種評價方法的結(jié)果均表明地震作用下三家地滑坡處于欠穩(wěn)定狀態(tài)。 4、利用FLAC3D軟件動力分析模塊對三家地滑坡在地震作用前后的穩(wěn)定性進行了數(shù)值模擬分析，結(jié)果表明，地震前三家地滑坡處于穩(wěn)定狀態(tài)，地震作用下滑坡整體上處于欠穩(wěn)定狀態(tài)，滑坡體前部位移和剪應(yīng)變增量明顯增大。 5、利用正交試驗法和改進的灰色關(guān)聯(lián)法，分析了三家地滑坡穩(wěn)定性主要影響因素的敏感性，結(jié)果表明，地震作用是僅次于滑帶土內(nèi)摩擦角的影響因素，隨著地震烈度的增大，滑坡穩(wěn)定系數(shù)的減小趨勢增大。 6、對黃土滑坡的主要防治措施進行了分析，研究了影響黃土滑坡綜合治理方案決策的主要因素指標，提出了黃土滑坡治理方案評價指標的優(yōu)化賦權(quán)計算方法，并建立了黃土滑坡治理方案優(yōu)選模型。確定了三家地滑坡的最優(yōu)治理方案為：前緣回填反壓工程+溝道泥石流治理工程+排水工程。
[Abstract]:The loess region in northwest China has a very special geological tectonic background. The loess landslide disasters occur frequently in this area and most of them are located in the high intensity earthquake area. In this paper, the geological environment and characteristics of loess landslide in central and southern Gansu are studied, and the characteristics of loess landslide in the study area are analyzed by means of a large number of geological investigation, laboratory tests, theoretical calculation and numerical simulation. The seismic stability and prevention techniques are systematically studied, and the following results are obtained: 1. The characteristics and formation mechanism of typical loess landslides in the study area are studied. The results show that, Sanjiadi landslide is a giant loess-mudstone landslide. The poor geological structure of slope body and the long-term erosion of the front edge of the landslide caused by Chen Ligou debris flow are the main factors leading to the formation of the old landslide. The "5.12" Wenchuan earthquake induced the massive resurrection of the landslide front and the posterior edge of the landslide, which was caused by the front sliding traction to produce a through crack, which is a traction landslide. 2. In view of the static state of the soil in the typical loess landslide slide zone, Direct shear test, static triaxial test and dynamic triaxial test are carried out. The results show that the peak value and residual value of cohesive force and internal friction angle decrease with the increase of water content in the slip zone of Jiuzhou and Sanjia landslide. The dynamic elastic modulus of the sliding zone soil decreases with the increase of the strain, and the damping ratio increases slowly with the increase of the following strain, and fluctuates in a very small range. The dynamic cohesive force and dynamic internal friction angle decrease with the increase of water content. Considering 5 kinds of 16 factors, a fuzzy comprehensive evaluation model of loess landslide stability under earthquake is established. Based on the randomness and fuzziness of geotechnical parameters and seismic acceleration, a method for calculating the reliability and fuzzy random reliability of loess landslide stability under earthquake is presented. The established model is applied to the seismic stability analysis of the landslide in Wenchuan earthquake area, and the stability coefficient of the landslide under the earthquake condition is calculated by using the pseudostatic method. The results of these methods show that the three landslides are in an unstable state. 4. The stability of the three landslides before and after the earthquake is simulated and analyzed by using the dynamic analysis module of FLAC3D software. The results show that the landslide is in a stable state before the earthquake, and the landslide is in an unstable state as a whole under the earthquake. The increment of displacement and shear strain in front of landslide is obviously increased. 5. By using orthogonal test method and improved grey correlation method, the sensitivity of the main factors affecting the stability of the landslide is analyzed. The results show that, Seismic action is second only to the internal friction angle of sliding zone soil. With the increase of seismic intensity, the decreasing trend of landslide stability coefficient increases. 6. The main prevention measures of loess landslide are analyzed. This paper studies the main factors influencing the decision-making of the comprehensive control scheme of loess landslide, puts forward the optimization and weighting calculation method of the evaluation index of the loess landslide control scheme, and establishes the optimal selection model of the loess landslide control scheme. The optimal treatment scheme of three landslides is as follows: the drainage project of gully debris flow treatment in the backfill and back pressure project of the leading edge.
【學位授予單位】：長安大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TU444;P642.22

【參考文獻】

相關(guān)期刊論文 前10條

1 匡樂紅;徐林榮;劉寶琛;;組合賦權(quán)法確定地質(zhì)災害危險性評價指標權(quán)重[J];地下空間與工程學報;2006年06期

2 方樟;肖長來;梁秀娟;馮波;;松嫩平原地下水脆弱性模糊綜合評價[J];吉林大學學報(地球科學版);2007年03期

3 王偉;張永波;葉浩;郭嬌;王乾;張禮中;蔡子昭;梁國玲;張春英;;內(nèi)蒙古砒砂巖的模糊聚類分析[J];吉林大學學報(地球科學版);2009年06期

4 王志仁;層次分析法中權(quán)的最小平方法[J];東北電力學院學報;1995年02期

5 毛尚禮;余湘娟;張富有;;昆明黏性土動力特性試驗研究[J];地震工程與工程振動;2011年02期

6 許領(lǐng);戴福初;閔弘;;黃土滑坡研究現(xiàn)狀與設(shè)想[J];地球科學進展;2008年03期

7 楊明;張可能;劉宇飛;楊慶光;;基于MATLAB的均質(zhì)土坡穩(wěn)定可靠度的蒙特卡羅模擬[J];地質(zhì)與勘探;2009年01期

8 邵順妹,鄒敏;古浪-海原地區(qū)滑坡分布規(guī)律的模糊綜合評判[J];地震學刊;1994年01期

9 陳永明;石玉成;;中國西北黃土地區(qū)地震滑坡基本特征[J];地震研究;2006年03期

10 于遠祥,楊梅忠,孫學陽;黃陵礦區(qū)滑坡的穩(wěn)定性評價與防治[J];礦業(yè)安全與環(huán)保;2004年04期

相關(guān)博士學位論文 前3條

1 鄧龍勝;強震作用下黃土邊坡的動力響應(yīng)機理和動力穩(wěn)定性研究[D];長安大學;2010年

2 龍建輝;高速遠程黃土滑坡預測預報方法研究[D];長安大學;2008年

3 馬建全;黑方臺灌區(qū)臺緣黃土滑坡穩(wěn)定性研究[D];吉林大學;2012年

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