【作者】 范余敏；

【导师】 黄润秋；

【作者基本信息】 成都理工大学 ， 地质工程， 2010， 硕士

【摘要】 雅安经石棉至泸沽高速公路是国家高速公路网中的重要路段,线路所经区域地形复杂、地貌类型多样,公路沿线附近断裂构造发育,地震活动频繁。地震发生时,常常造成边坡失稳,严重危害公路、房屋建筑等安全,如何保证地震作用下的边坡稳定性是亟待解决的难题。本文以雅泸高速公路C17段磨房沟古滑坡为例,在充分研究滑坡工程地质条件的基础上,采用FLAC3D数值模拟手段,研究了古滑坡在地震作用下的动力响应,通过评价滑坡稳定性状态,提出了相应的治理措施。研究取得主要成果如下:(1)运用有限差分软件FLAC3D模拟研究了古滑坡在地震作用下的动力响应。数值模拟过程中,在坡体布置了9个监测点,得出以下认识:①地震作用下古滑坡的最大位移达1.28m,沿主滑方向位移最大值为1m,边坡变形明显区域主要集中在坡体由缓变陡的部位,地震力作用下,滑坡体表层位移变化量较大;竖向加速度对磨房沟古滑坡的变形影响很大,当地震竖向加速度与水平向加速度相等时,滑坡最大位移量为1.91m,相比竖向加速度为0时,位移量增加了约50%,沿主滑方向的位移最大值为1.38m,滑体与下覆岩土体交界处位移量相比竖向加速度为0时变化不大,由此可见,竖向加速度对滑坡堆积体坡表的影响较大。②滑坡体内的最大不平衡力在地震时逐渐增大,6~7S时最大不平衡力达到最大值,然后逐渐回落。③在主滑方向不同高程处的位移量有随高程的升高而增加的趋势,同一高程处的位移量,主滑方向较两侧的位移量大;同一位置处,边坡的位移随深度的增加而减小。④滑坡在地震动力作用下的加速度放大系数随高程的增加呈先增加后减小的趋势,在高程1285m处放大系数达到最大值1.95,此时加速度值为13.7m/s2;高程在1285m以上的加速度放大系数均小于1。加速度随深度的变化呈先增加后减小的规律,在深度为15m处水平加速度放大系数达到最大值0.67,由滑体厚度约15m左右判断出水平加速度最大值部位也是滑面所在处。⑤剪应变增量主集中在滑坡体东侧,可分为三个区域,其高程分别为I区:1318m~1325m、II区:1328m~1339m、III区:1343m~1348m,剪应变增量最大值为0.046。对计算模型施加竖向加速度时,边坡剪应变增量变大,最大值集中在三个区域,与竖向加速度为0时一致,剪应变增量最大值为0.067,相比竖向加速度为0时增加了约46%,滑面附近剪应变增量在0.007~0.014之间,基本上无变化。⑥滑坡体表面、滑坡体周界以及滑坡体中心部分区域都处于张拉和剪切破坏状态,滑坡体中部高程在1329m~1354m之间大部分区域处于剪切状态。(2)在考虑了边坡动态响应具有水平向放大效应和竖直向放大效应的基础上,针对该边坡设计了治理措施,通过有效检验,治理措施是有效地。更多还原

【Abstract】 The highway from Ya’an-Shimian-Lugu is important sections of the State Highway Network. The line through the region where have complex topography and diverse landscape. Faults development along highway, seismic activity frequently. Slope instability often induced after earthquake and damage roads severely, harm to highway and housing construction. It is a pressing problem to ensure slope stability under earthquake. In this paper, take C17 Mofanggou ancient landslide of Ya’an-Lugu highway as an example,based on full study to the engineering geological conditions, use numerical simulation methods to study dynamic response under the earthquake of ancient landslides, then analyze ancient landslide stability and propose the corresponding support measures. Main results as follows:(1 ) Use the finite difference software—Flac3D to simulate dynamic response of the ancient landslide response under earthquake. Layout 9 monitoring points in landslide body .According to numerical simulation of slope dynamic response under earthquake, we can arrive at the following understanding :①Under earthquake, maximum displacement of the ancient landslide is 1.28m, the maximum displacement along the main slip direction is 1m, the obvious deformations mainly concentrate on site that the terrain from gentleness to steepness .Landslide surface has a large amount displacement under earthquake. Vertical acceleration affect Mofanggou ancient landslide deformation greatly , when the vertical acceleration equal to horizontal acceleration, the maximum displacement of landslide is 1.91m, the displacement increased about 50% compared with the vertical acceleration is 0; The maximum displacement is 1.38m along the main sliding direction.Compared with the vertical acceleration is 0,the displacement at junction of sliding body and lower rock mass changed slightly.Therefore, vertical acceleration affect slope surface greatly. ②Maximum unbalanced force of landslide body increase gradually under earthquake, 6 ~ 7s reach its maximum value and then reduce gradually.③Displacement increase with elevation along main sliding direction. At the same elevation ,the displacements of main sliding direction is higher than two sides . At the same location, the displacement decreases with depth increasing.④Seismic acceleration amplification factor increase with the increasing of the elevation and then decreased, maximum magnification factor is 1.95 at elevation 1285m and at the moment the acceleration is 13.7m/s2; Magnification factor is less than 1 at elevation above the 1285m. Acceleration was increased and then decreased with depth, maximum horizontal acceleration amplification factor is 0.67 at the depth of 15m. Landslide thickness is about 15m, so the maximum level acceleration at the area of slip surface.⑤Shear strain increment can be divided into three regions, the elevation was :I area: 1318m ~ 1325m, II area: 1328m ~1339m, III area: 1343m ~ 1348m, the maximum shear strain increment is 0.046,concentrated in east of landslide. Shear strain increment of slope becomes larger when vertical acceleration imposed on the calculation model, as the same as vertical acceleration is 0, the maximum concentration in three regions, maximum value is 0.067, increased about 46% compared with vertical acceleration is 0,Shear strain increment between 0.007 and 0.014 near the sliding surface, unchanged essentially.⑥Landslide surface、landslide perimeter and central part of the landslide area are in a state of tension and shear failure.At elevation 1329m ~1354m, most regions in the shear state at central part of landslides.(2) Considering the dynamic response of the ancient landslide has the horizontal and vertical amplification, design the slope support measures.Through effective inspection,the control measures are effective.更多还原