【作者】 王丽君；

【导师】 邓荣贵；

【作者基本信息】 西南交通大学 ， 岩土工程， 2013， 硕士

【摘要】 水库滑坡在水电工程建设中的一种常见地质灾害,当滑坡滑入库区中可能会引起减小库容,威胁大坝安全等危害。由于西尔瓜子滑坡是一个大型古滑坡与一个复活的新滑坡组成,此滑坡的稳定性将直接影响麻窝集镇以及贝尔隧道的安全。本文综合运用工程地质及水文地质、岩体力学、结构力学及数值模拟等理论和方法,研究了古滑坡的历史成因、新滑坡的复活历程以及分析预测滑坡的稳定性前景以及对相关工程的影响,结合结构力学分析新型抗滑结构的工作原理,获得了以下几个方面的研究成果：(1)滑坡区位于毛尔盖水电站上游,毗邻麻窝集镇,贝尔隧道穿过滑坡区域；区内地势较陡,覆盖层为松散堆积的块石碎石土,下覆基岩为变质砂岩夹千枚岩和变质石英砂岩,滑坡的滑动变形表现为覆盖层滑动,滑带为基覆界限；地震烈度为Ⅶ度,勘查区属区域构造基本稳定区；滑坡区地下水空间形态主要表现为松散覆盖层孔隙潜水,其次为基岩裂隙潜水,地下水主要由库区河水来补给,其次为大气降雨补给；滑坡区的物理地质现象主要表现为滑坡和库岸再造。(2)古滑坡为一形态不规则的滑坡体,表现为前缘和中部稍宽,后缘则逐步收敛；经现场调研分析和过程机制分析西尔瓜子古滑坡为大型岩质倾倒滑移复合式滑坡,在空间上是浅部的弯曲拉裂与较深部的滑移压致拉裂的组合。据调查,滑坡体在该后缘部位数十年来未曾变形,说明古滑坡在滑体后部目前已趋于稳定状态。(3)西尔瓜子古滑坡在未蓄水之前处于稳定状态,在“5.12”汶川大地震后,经过长期沉积固结的碎石土堆积体重新变得松散,加之水库开始蓄水后,水位达到约2085m,古滑坡前缘开始变形滑动。通过运用FLAC3D有限元软件模拟了滑坡在不同库水位时的变形滑动机理,从模拟结果来看,滑坡体变形机制表现为一个牵引—推移式滑坡共同作用的结果,滑带及滑动面的位置位于基覆界面。并预测分析了该滑坡约在库水位2105m的时候整个坡体发生破坏。(4)通过滑坡稳定性分析计算,对古滑坡和新滑坡在水库死水期、运营期以及骤升骤降期在各种工况下进行稳定性评价,总体上看古滑坡体失稳可能性小、新复活区出现失稳可能性很大。新复活区失稳后,后部临空的古滑坡推测的滑坡次级解体会在暴雨和地震工况下失稳。通过对滑坡体滑入水中形成的涌浪分析,麻窝集镇的安全不会造成太大影响。(5)弧形间隔排列桩-桩顶连系梁空间抗滑结构是指抗滑桩呈弧形间隔排列,桩顶设置连系梁,以抵抗滑坡推力的一种新型抗滑结构。本文通过结构力学和岩土体力学综合分析结构的工作原理,运用西尔瓜子滑坡治理工程实例证明计算模型的内力和位移分布合理性并与传统悬臂抗滑桩做比较分析,得出新型抗滑桩在治理滑坡时的优越性。更多还原

【Abstract】 Reservoir landslide in the construction of hydropower projects in a common geological disasters, when the landslide slip into the reservoir area may cause a relatively large impact, including reducing the capacity of threat to the dam safety. Xierguazi landslide is a large ancient landslide with a resurrection of the new landslide composed of the landslide stability will directly affect the safety of Ma Wo town and Bell tunnel. This paper uses the theories and methods of engineering geology and hydrogeology, rock mechanics, structural mechanics and numerical simulation to study the ancient landslide history of the causes of the resurrection of the course as well as analysis of new landslide prediction of the stability of the landslide prospects and associated works., combined with the structural mechanics analysis of the works of the new anti-slide structure, access to the following aspects of the research results as follows:1. The landslide area is located in the Maoergai station upstream, adjacent to Ma Wo town, Bell tunnel through the landslide area; the terrain is steep, overburden loose stone rubble piled soil, under the bedrock of metamorphic sandstone folder phyllitesegment and metamorphic quartz sandstone, landslide deformation of the sliding performance overlay slide; seismic intensity vii degree; the region without a regional fracture by secondary associated compression shear fault more than an extension of the shorter interlayer extrusionfracture zone and fault-based, and the other through the good jointed development, is a regional tectonic stability district; landslide spatial form of groundwater mainly pore diving for loose overburden, followed by bedrock fissure water, groundwater mainly bythe reservoir area the water supply, followed by rainfall recharge; the landslide area to the geological phenomenon mainly as landslides and reservoir banks and recycling.2. Ancient landslide as an irregular landslide, the leading edge and central slightly wider, the trailing edge is gradually converge, as posed by the armchair-like away from the heart rate of about0.54oval in the landslide whole plane; field research analysisand the process mechanism the Xierguazi of ancient landslide slip composite landslides, dumping large rock in space is a combination of bending shallow crack and deep slip of the Ministry of pressure-induced crack. According to the survey, landslide in the after edge of the site for decades has not been deformed, indicating that the ancient landslide in the back of the landslide has been stabilized state.3. The ancient Xierguazi landslide is in a stable state of water before and after the "5.12" Wenchuan earthquake, after long-term deposition of consolidation gravel soil piled weight new loose, coupled with the reservoir began filling with water, the water level reached about 2085m, the leading edge of the ancient landslide deformation slide. By use of FLAC3D Finite Element software simulate a landslide deformation sliding mechanism when the water level in the different libraries, from the simulation results, the performance of the landslide deformation mechanism of a tractor-goes style landslide result of joint action, slip band and the position of the sliding surface is located based coating interface. when the water level in the2105m, landslides will be completely destroyed.4. Landslide stability analysis of ancient landslides and new landslides in reservoirs of stagnant water, the operator of a sudden jump in the sudden drop of the stability evaluation under various conditions, overall instability of the ancient landslide the possibility of small, newThe resurrection District instability is very likely. New resurrection District instability after, the rear of the invading ancient landslide speculate landslide secondary disintegration of destabilization in the heavy rain and seismic conditions. Landslide surge into the water to form analysis, the safety of Ma Wo town is not much impact.5. The arc interval arranged in piles-the top of the pile with the Department of beam space anti-slide structure is the anti-slide pile curved interval arranged pile top set with tie beams to resist the landslide thrust a novel anti-slide structure. In this thesis, structural mechanics and geotechnical physical science works for the comprehensive analysis of the structure, the use of the Xierguazi landslide control engineering examples prove computational model of internal forces and displacement distribution is reasonable to do a comparative analysis with traditional cantilever anti-slide pile obtained a new type of anti-slide pile superiority in treating landslide.更多还原