本文選題：黃土滑坡 + 形成機理��； 參考：《西南交通大學》2017年碩士論文

【摘要】：黃土滑坡是黃土地區(qū)最為嚴重的地質災害之一,黃土具有的特殊物質組成和工程特性,使得黃土滑坡的形成條件和變形機理呈現(xiàn)出復雜多變性。秦安地區(qū)黃土滑坡災害較為嚴重,制約了當?shù)氐慕?jīng)濟發(fā)展,縣城西北部的王家墩滑坡更是威脅到寶(雞)蘭(州)客運專線的運營安全。本文以寶蘭客專擬經(jīng)線路王家墩滑坡為研究對象,結合研究區(qū)區(qū)域地質條件,通過現(xiàn)場勘查、資料收集,運用理論分析計算與數(shù)值模擬等方法,對王家墩滑坡的形成機制、變形機理及穩(wěn)定性狀況展開深入的探討性研究。主要研究內(nèi)容和結論如下:(1)王家墩滑坡屬黃土老滑坡,規(guī)模巨大(方量近1.46億m3),后緣高程1650m,前緣高程1290m,高差超過300m,地形起伏上緩下陡,中上部坡度15°～20°,前緣較陡,坡度30°～40°。通過陡坎邊界將整個滑坡劃分為三個大區(qū)。坡體內(nèi)沖溝陡坎較多,滑坡前緣可見拉張裂縫和泉水出露;(2)王家墩滑坡形成受地層巖性、地形地貌、地震,大氣降水等因素控制,在經(jīng)歷蠕動變形、滑移變形、穩(wěn)定三個階段后,目前滑坡高陡前緣已壓覆至葫蘆河一級階地,前緣厚層黃土堆積對滑坡中后部起到一定阻滑作用;(3)定性評價王家滑坡穩(wěn)定性后,利用傳遞系數(shù)法對王家墩滑坡Ⅰ區(qū)、Ⅱ區(qū)及ⅠⅡ區(qū)前緣潛在滑體進行滑坡穩(wěn)定性定量計算。得知王家墩滑坡總體穩(wěn)定性良好,Ⅰ區(qū)前緣潛在滑體在暴雨工況下穩(wěn)定性較差;(4)結合FLAC-3D數(shù)值模擬軟件,選擇穩(wěn)定性一般的Ⅰ區(qū)前緣潛在滑體進行數(shù)值分析,分析其在天然及暴雨兩種工況下的變化特點。數(shù)值分析結果與穩(wěn)定性計算結論一致;(5)基于對Ⅰ區(qū)前緣潛在滑體變形破壞后對滑坡整體堆載反壓作用減弱的考慮,再選擇Ⅰ區(qū)整體坡體做為數(shù)值分析對象,以天然工況為條件,對比分析Ⅰ區(qū)前緣潛在滑體失穩(wěn)破壞前后坡體的變形機理及穩(wěn)定性變化規(guī)律。結果表明,滑坡前緣潛在滑體變形破壞后,坡體內(nèi)應力重分布,穩(wěn)定性狀況較失穩(wěn)破壞前顯著降低。
[Abstract]:Loess landslide is one of the most serious geological disasters in loess area. Loess has special material composition and engineering characteristics, which makes the forming conditions and deformation mechanism of loess landslide show complex variability. The loess landslide disaster in Qinan area is more serious, which restricts the local economic development, and the Wangjiadun landslide in the northwest of the county seat is a threat to the operation safety of Bao (Ji) Lan (Zhou) passenger dedicated line. Taking the Wangjiadun landslide as the research object, combining the regional geological conditions of the study area, the formation mechanism of the Wangjiadun landslide is studied by using the methods of field investigation, data collection, theoretical analysis and numerical simulation. The mechanism and stability of deformation are studied deeply. The main research contents and conclusions are as follows: the Wangjiadun landslide belongs to the old loess landslide with a large scale (nearly 146 million m ~ 3 ~ 3 m square, 1650 m in the back edge, 1290 m in the front edge, and over 300 m in height). The topographic fluctuation is slow and steep, the middle and upper part of the landslide is 15 擄~ 20 擄, the front edge is steep, the slope is 30 擄~ 40 擄. The whole landslide is divided into three regions by the boundary of the steep ridge. The formation of Wangjiadun landslide is controlled by stratigraphic lithology, topography, geomorphology, earthquake, precipitation and other factors, and experienced creep deformation and slip deformation. After three stages of stabilization, at present the high and steep front edge of the landslide has been compressed to the first level of the Hulu River terrace, and the thick loess accumulation in the front edge of the landslide has played a certain role in preventing the slide in the middle and back of the landslide.) after qualitative evaluation of the stability of the Wangjia landslide, Based on the transfer coefficient method, the landslide stability was calculated quantitatively in the front edge of Wangjiadun landslide area 鈪，

本文編號：1872158