西山村滑坡地震力加卸载响应特征及稳定性研究

发布时间：2018-05-14 01:13

本文选题：西山村滑坡 + 地震数值模拟　；参考：《成都理工大学》2017年硕士论文

【摘要】：地震动力作用下的斜坡稳定性研究对于我国地震高发的西南山区有着重要意义。本文以西山村滑坡为研究对象,在搜集整理研究区域相关地质资料并对西山村滑坡形态、地质结构特征、宏观变形特征等详细调查与分析的基础上,对西山村滑坡在地震动力荷载作用下的动力响应及加卸载响应规律进行深入分析研究,主要研究内容有以下几个方面:(1)分析了理县西山村滑坡基本工程地质条件。开展现场调查和室内试验分析,研究堆积层滑坡的物质组成、结构特征以及强度、渗透特性,掌握滑坡的各项基本的岩土力学性能指标数据,为后续数值模拟研究、参数取值等提供依据。(2)结合西山村滑坡的监测数据以及其宏观变形特征,对滑坡进行变形分区,研究了各个变形区的变形特点,分析了滑坡的形成及变形机理。(3)研究了西山村滑坡在地震作用下的动力响应特征。通过数值模拟的方法,研究西山村滑坡在地震动力作用下的位移、变形速率的动力响应时程特征,分析其变形特征,并对计算模拟结果进行讨论,进而分析了滑坡在地震作用下的变形破坏机理。(4)根据变形的数值模拟结果,采用加卸载响应比理论,分析研究西山村滑坡在不同地震荷载下的位移、速度、加速度加卸载响应规律。(5)采用加卸载响应度判据,对地震动力作用下西山村滑坡的稳定性进行定量分析,并与常规的斜坡稳定性分析方法进行比对,验证其正确性。通过以上研究得到了以下结论和成果:(1)西山村滑坡位于理县通化乡杂谷脑河左岸,地理坐标为北纬30°54′43″,东经102°32′46″。滑坡整体上呈前窄后宽的长条带状,滑坡前缘以杂谷脑河为界,高程约为1510m;滑坡左右两侧以冲沟为界;滑坡后缘以一近直立的滑坡壁为界,后缘高程约为3300m。滑坡前后缘高差约1790m,滑坡体纵长约为3800m,平均宽度约680m,最大宽度约为980m,滑坡堆积体厚度在10~80m之间,整体规模约1.7×108m3。滑坡未见明显滑带层。(2)西山村滑坡变形区域主要分布在滑坡的左侧前缘和左侧中部,根据滑坡复活变形特征,其变形可以分为I、II、III三个区域,其中变形Ⅰ区变形最为剧烈,Ⅱ区次之,Ⅲ区较小。综合宏观变形及监测数据,目前滑坡复活变形方式表现为牵引式滑坡,变形力学模式为蠕滑-拉裂型。(3)西山村滑坡对地震荷载的响应总体上呈现出非线性的特点,滑坡不同区域响应差异明显。滑坡表面的地震力响应呈现出前部较大,中后部逐渐减小的特征;滑坡深部地震力响应呈现出中部较大,前后缘较小的特征。同时,西山村滑坡表面地震力响应要大于滑坡深部响应。此外,滑坡在地震荷载下的动力响应在空间上还表现出各向异性的特点,滑坡在水平方向上的动力响应大于竖直方向,说明滑坡在地震作用下主要向着临空面的方向发生变形。(4)西山村滑坡的地震力响应存在滞后性,具体表现在:滑坡表面上位置越高的监测点动力响应就越滞后,监测点埋深越浅动力响应越滞后。(5)不同类型地震波对斜坡的动力响应有很大的影响。在同一振动强度下,地震波的振动频率越高,斜坡体上质点的变形就约趋于线性;反之,质点变形则会呈现出周期性波动增大的趋势。同样随着振动频率的提高,斜坡的动力响应会越来越积极,响应的滞后时间越来越短。此外,随着地震波的振幅的增大,震后斜坡的位移也会增大。(6)西山村滑坡在地震力作用下加卸载响应比时序曲线表现出在1.0左右波动震荡的特征。当响应时序曲线的表现出非线性特征时,对应的加卸载响应比曲线会出现一个峰值。同时,采用同一加卸载参量的加卸载响应比曲线会保持相似的波动趋势,说明加卸载响应比值的变化只和各参量的变化趋势有关。(7)西山村滑坡在持续时长为5s峰值加速度为0.15g的地震荷载作用下,其最小加卸载响应度为1.19,说明震后滑坡仍处于稳定状态。本研究对于预防西南山区滑坡地质灾害和维护人民的生命财产安全,具有十分重要的现实意义;同时也可以为西南山区类似滑坡的地震稳定性评价提供参考依据。
[Abstract]:The study of slope stability under seismic dynamic action is of great significance to the southwest mountainous area of China's earthquake. This paper takes the Xishan landslide as the research object, and based on the detailed investigation and analysis of the regional geological data and the detailed investigation and analysis of the landslides, geological structure features and macroscopic deformation characteristics of Xishan village. The dynamic response of the village landslide and the response law of loading and unloading under the earthquake dynamic load are deeply analyzed and studied. The main contents are as follows: (1) the basic engineering geological conditions of the landslide in Xishan village of Lixian County are analyzed. The material composition, structural characteristics and strength of the landslides are studied by field investigation and laboratory tests. Degrees, permeability characteristics, grasp the basic rock and soil mechanical properties of landslide data, for the follow-up numerical simulation research, parameter values and so on. (2) combining the monitoring data of the landslide in Xishan village and its macroscopic deformation characteristics, the deformation zone of the landslide is divided, the deformation characteristics of each deformation area are studied, and the formation and change of the landslide is analyzed. (3) the dynamic response characteristics of the landslide in Xishan village under the earthquake action are studied. Through numerical simulation, the displacement of the landslide in the Xishan village and the dynamic response time history of the deformation rate are studied, the deformation characteristics are analyzed, and the simulated results are discussed, and then the landslide is analyzed under the action of the earthquake. (4) according to the numerical simulation results of the deformation, the displacement, velocity, acceleration and unloading response laws of Xishan village landslides are analyzed by loading and unloading response ratio theory. (5) the stability of the landslide in Xishan village under the action of ground motion is quantitatively analyzed by the criterion of loading and unloading response degree, and the stability of the landslide under the action of ground motion is quantitatively analyzed. The following conclusions and results are obtained through the comparison of the conventional slope stability analysis method. The following conclusions and results are obtained: (1) the landslide is located on the left bank of the Zay valley river in the Tonghua township of the Lixian County, the geographical coordinates are 30 degrees 54 '43 "in the North latitude and 102 degrees 32' 46" in the East, and the landslide whole body is a long strip with a narrow front and a narrow width, and the front edge of the landslide is mixed. The height of the valley is about 1510m, and the elevation is about the boundary of the gully in the left and right sides of the landslide; the back edge of the landslide is bounded by a near vertical landslide wall, the elevation of the back edge is about 1790m, and the length of the landslide body is about 3800m, the average width is about 680m, the maximum width is about 980m, the thickness of the landslide accumulation is between 10~80m, and the overall scale is about 1.7 x 108m. 3. landslides do not have obvious sliding zone. (2) the deformation area of the landslide in Xishan village is mainly distributed in the left front edge and the left middle part of the landslide. According to the characteristics of the landslides' resurrection and deformation, the deformation can be divided into three regions, I, II and III, of which the deformation I area is the most severe, the second region is the second and the third is smaller. The form of the live deformation is tractive landslides, and the deformation mechanics model is creep and crack type. (3) the response of the landslide to the earthquake load is nonlinear in general, and the response difference is obvious in different landslides. The seismic response of the landslide surface appears to be larger in the front and gradually decreasing in the middle and rear parts, and the deep seismic force of the landslide. The response is larger in the middle and smaller in the front and rear edge. At the same time, the seismic response of the landslide on the Xishan village is greater than the deep response of the landslide. In addition, the dynamic response of the landslide is also anisotropic in space, and the dynamic response of the landslide in the horizontal direction is greater than the vertical direction, indicating that the landslide is in the earthquake. (4) the seismic response of the landslide in Xishan village is lagging behind. The dynamic response of the monitoring point on the surface of the landslide is lagging behind and the more shallow dynamic response of the monitoring point is lagging behind. (5) the different types of seismic waves have a great influence on the dynamic response of the slope. The higher the vibration frequency is, the higher the vibration frequency of the seismic waves, the deformation of the particles on the slope tends to be linear. On the contrary, the deformation of the particle will show a tendency to increase the periodic fluctuation. As the vibration frequency increases, the dynamic response of the slope will become more active and the lag time of the response becomes shorter and shorter. In addition, with the vibration wave vibration. As the amplitude increases, the displacement of the post earthquake slope will also increase. (6) the response ratio curve of the Xishan village landslide is characterized by fluctuating oscillation at about 1. When the response time sequence curve shows a nonlinear characteristic, the corresponding load and unload response ratio curve will have a peak. At the same time, the same loading and unloading parameter is used. The load and unload response ratio curve will keep the similar fluctuation trend, indicating that the change of the load and unload response ratio is only related to the variation trend of the parameters. (7) the minimum loading and unloading response degree of the Xishan landslide is 1.19 under the earthquake load of the peak acceleration of 5S, which indicates that the landslide is still in a stable state after the earthquake. The study is of great practical significance for the prevention of landslide geological hazards in the southwest mountain area and the maintenance of the safety of people's life and property. At the same time, it can also provide reference for the seismic stability evaluation of similar landslides in the southwest mountainous area.

【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.22

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