宝兰客专王家墩滑坡形成机理与稳定性研究

发布时间：2018-05-11 03:14

  本文选题：黄土滑坡 + 形成机理　； 参考：《西南交通大学》2017年硕士论文

【摘要】：黄土滑坡是黄土地区最为严重的地质灾害之一,黄土具有的特殊物质组成和工程特性,使得黄土滑坡的形成条件和变形机理呈现出复杂多变性。秦安地区黄土滑坡灾害较为严重,制约了当地的经济发展,县城西北部的王家墩滑坡更是威胁到宝(鸡)兰(州)客运专线的运营安全。本文以宝兰客专拟经线路王家墩滑坡为研究对象,结合研究区区域地质条件,通过现场勘查、资料收集,运用理论分析计算与数值模拟等方法,对王家墩滑坡的形成机制、变形机理及稳定性状况展开深入的探讨性研究。主要研究内容和结论如下:(1)王家墩滑坡属黄土老滑坡,规模巨大(方量近1.46亿m3),后缘高程1650m,前缘高程1290m,高差超过300m,地形起伏上缓下陡,中上部坡度15°～20°,前缘较陡,坡度30°～40°。通过陡坎边界将整个滑坡划分为三个大区。坡体内冲沟陡坎较多,滑坡前缘可见拉张裂缝和泉水出露;(2)王家墩滑坡形成受地层岩性、地形地貌、地震,大气降水等因素控制,在经历蠕动变形、滑移变形、稳定三个阶段后,目前滑坡高陡前缘已压覆至葫芦河一级阶地,前缘厚层黄土堆积对滑坡中后部起到一定阻滑作用;(3)定性评价王家滑坡稳定性后,利用传递系数法对王家墩滑坡Ⅰ区、Ⅱ区及ⅠⅡ区前缘潜在滑体进行滑坡稳定性定量计算。得知王家墩滑坡总体稳定性良好,Ⅰ区前缘潜在滑体在暴雨工况下稳定性较差;(4)结合FLAC-3D数值模拟软件,选择稳定性一般的Ⅰ区前缘潜在滑体进行数值分析,分析其在天然及暴雨两种工况下的变化特点。数值分析结果与稳定性计算结论一致;(5)基于对Ⅰ区前缘潜在滑体变形破坏后对滑坡整体堆载反压作用减弱的考虑,再选择Ⅰ区整体坡体做为数值分析对象,以天然工况为条件,对比分析Ⅰ区前缘潜在滑体失稳破坏前后坡体的变形机理及稳定性变化规律。结果表明,滑坡前缘潜在滑体变形破坏后,坡体内应力重分布,稳定性状况较失稳破坏前显著降低。
[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 掳~ 20 掳, the front edge is steep, the slope is 30 掳~ 40 掳. 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，

本文编号：1872158