地震震裂边坡的形成机制及降雨稳定性研究

发布时间：2018-05-23 15:54

本文选题：震裂边坡 + 降雨　；参考：《江苏科技大学》2015年硕士论文

【摘要】：地震和降雨都是引起边坡失稳的重要诱导因素,地震不仅能引发山体滑坡等直接灾害,还能使大量山体出现开裂松动,形成具有潜在灾害的震裂边坡,而降雨入渗使得边坡土体内的孔隙含水量增大,地下水潜水面升高,从而导致滑面处土体软化,进一步产生滑坡灾害,对于一些地震灾区,同样也属于降雨较为充分的地区,大量的地震震裂边坡在降雨的作用下稳定性如何变化是防灾减灾的重要课题。本文根据大量的地震震裂边坡的发生资料,归纳出震裂边坡的发展规律,初步分析了地震震裂边坡的破坏机制,并在饱和—非饱和土渗流及非饱和土强度理论的基础上,运用Abaqus有限元软件对地震震裂边坡降雨入渗过程进行模拟,并得出其稳定性变化规律。本文的主要内容如下:1.整理古浪8.0级地震、汶川8.0级地震和玉树7.1级地震三次典型大地震地震灾区震裂边坡的详细调查资料,归纳和总结了地震震裂边坡的发生、发展及其分布的特点和规律。2.基于边坡特性的影响效应分析和地震波对边坡的作用效应理论,采用示意图的方式直观地分析了地震震裂边坡的破坏机制。3.基于饱和—非饱和土渗流理论,利用Abaqus有限元软件对震裂边坡的降雨过程进行了数值模拟,分析了降雨过程中震裂边坡(特别是地震裂缝附近特征点)的孔隙水压力、饱和度、位移和等效塑性应变的变化情况,从而评价降雨过程中地震裂缝对边坡渗流产生的影响。4.基于前文统计分析的震裂边坡发展特征,设计不同的数值模拟工况,在非饱和土强度理论的基础上,利用强度折减法对不同裂缝位置、裂缝深度、降雨强度、降雨持时和土体渗透系数下震裂边坡降雨稳定性进行研究,分析出不同影响因素对震裂边坡稳定性的影响规律。
[Abstract]:Earthquake and rainfall are important inductive factors of slope instability. Earthquake can not only cause landslide and other direct disasters, but also cause cracking and loosening of a large number of mountain bodies, forming a cracked slope with potential disasters. Rainfall infiltration increases the pore water content in the slope soil and the groundwater diving surface, which results in the softening of soil on the slip surface and further landslide disaster. For some earthquake-stricken areas, they also belong to the areas with relatively adequate rainfall. How to change the stability of a large number of seismic cracked slopes under the action of rainfall is an important subject of disaster prevention and mitigation. Based on a great deal of data of earthquake crack slope, this paper sums up the development law of earthquake crack slope, analyzes the failure mechanism of earthquake crack slope, and based on the theory of saturated-unsaturated soil seepage and unsaturated soil strength, The process of rainfall infiltration of seismic crack slope is simulated by Abaqus finite element software, and its stability variation law is obtained. The main contents of this paper are as follows: 1. In this paper, the detailed investigation data of earthquake crack slope in three typical earthquake areas of Gulang earthquake (M = 8.0), Wenchuan earthquake (M = 8.0) and Yushu earthquake (M = 7.1) are reviewed, and the occurrence, development and distribution characteristics and regularity of seismic crack slope are summarized and summarized. Based on the analysis of the influence effect of slope characteristics and the theory of the effect of seismic wave on the slope, the failure mechanism of seismic cracked slope is analyzed intuitively by means of schematics. Based on the theory of saturated-unsaturated soil seepage, the rainfall process of the cracked slope is simulated by using Abaqus finite element software. The pore water pressure and saturation of the cracked slope (especially the characteristic points near the seismic fracture) during the rainfall process are analyzed. The variation of displacement and equivalent plastic strain, so as to evaluate the influence of seismic cracks on the seepage of slope during rainfall. Based on the statistical analysis of the characteristics of seismic crack slope development, different numerical simulation conditions are designed. On the basis of the strength theory of unsaturated soil, the strength reduction method is used to analyze the different crack positions, crack depth, rainfall intensity. The rainfall stability of cracked slope was studied under rainfall duration and soil permeability coefficient, and the influence of different factors on the stability of cracked slope was analyzed.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU43

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