降雨入渗对裂隙岩质边坡稳定性的影响

发布时间：2018-06-19 09:54

本文选题：降雨 + 入渗　；参考：《大连理工大学》2014年硕士论文

【摘要】：降雨对边坡稳定性研究是国内外岩土工程界十分关注的一个重要课题。特别是在我国西南地区,由于降雨较多、降雨强度大,经常发生滑坡、泥石流等自然灾害。所以说,降雨与边坡失稳破坏密不可分,对其研究势在必行。当发生强降雨,边坡更容易失稳破坏,这是显而易见的常识,研究边坡在降雨前后的稳定性变化问题是当务之急。四川省大岗山大渡河水电站位于西南地区,右岸边坡比较高陡,地下水位较低,而且属于岩质边坡,夏季雨水较多,比较容易发生滑坡灾害。因此,研究降雨入渗对其右岸岩质边坡稳定性影响是非常重要的课题。本文研究重点是分析降雨如何影响右岸边坡的稳定性,通过折减岩体的参数,从而研究安全系数的变化,用安全系数来衡量降雨对岩质边坡稳定性的影响。本文从以下几个方面进行分析研究： (1)基于裂隙岩质边坡渗流理论,建立了岩质边坡数值模型。 (2)从物理、化学以及力学作用上研究降雨对岩质边坡岩体强度的影响,雨水入渗后孔隙水压力对岩体应力状态的影响形式等。 (3)研究边坡稳定性的方法,包括求安全系数大小衡量边坡稳定性；FLAC3D软件可以用来计算边坡稳定性安全系数以及渗流方面的问题。边坡竖向位移、剪切破坏单元的范围、塑性贯通区的大小都是衡量边坡失稳的要素。掌握边坡失去稳定的机理及力学解释,为对边坡进行治理和防护打下基础。 (4)考虑岩质边坡在不同降雨强度、降雨持续时间以及不同渗透系数情况下边坡稳定问题；利用不同的分析方法,求取的安全系数并不相同；实例分析大岗山边坡岩体物理力学参数变化,包括内摩擦角、粘聚力、岩体容重、弹性模量的变化与安全系数的关系。降雨是诱发边坡失稳的主要因素。降雨入渗过程中,发生饱和-非饱和渗流过程,渗流场在降雨持续时时刻变化,渗流场与应力场共同决定着边坡稳定性。孔隙水压力的存在对含裂隙岩体强度有劣化的影响,通过对裂隙岩体的内摩擦角、粘聚力、容重、弹性模量等折减,求出安全系数减小,得出降雨是诱发岩质边坡失去稳定的主要因素。
[Abstract]:Research on slope stability caused by rainfall is an important subject in geotechnical engineering at home and abroad. Especially in the southwest of China, due to more rainfall, heavy rainfall, landslides, debris flow and other natural disasters occur frequently. Therefore, rainfall and slope failure are inseparable, it is imperative to study it. When strong rainfall occurs, slope is more vulnerable to instability and failure, which is an obvious common sense. It is urgent to study the stability of slope before and after rainfall. Dadu River Hydropower Station in Dagangshan, Sichuan Province is located in southwest China. The right bank slope is relatively high and steep, the groundwater level is low, and it belongs to rock slope. There is more Rain Water in summer, so it is easy to happen landslide disaster. Therefore, it is very important to study the influence of rainfall infiltration on the stability of rock slope on the right bank. The emphasis of this paper is to analyze how rainfall affects the stability of the slope on the right bank. By reducing the parameters of rock mass, the change of safety factor is studied, and the influence of rainfall on the stability of rock slope is measured by the factor of safety. Based on the seepage theory of fractured rock slope, a numerical model of rock slope is established in this paper. The influence of rainfall on rock mass strength and the influence of pore water pressure on rock mass stress state after Rain Water infiltration are studied in chemistry and mechanics. FLAC3D software can be used to calculate the safety factor of slope stability and seepage problems. The vertical displacement of slope, the range of shear failure element, and the size of plastic through zone are all factors to measure the slope instability. Grasp the mechanism of slope instability and mechanical interpretation, for slope treatment and protection of the foundation. 4) consider the rock slope under different rainfall intensity, rainfall duration and different permeability coefficient of slope stability; The variation of physical and mechanical parameters of rock mass in Dagangshan slope is analyzed by using different analysis methods, including the relationship between the variation of internal friction angle, cohesion, bulk density of rock mass, elastic modulus and safety factor. Rainfall is the main factor that induces slope instability. In the process of rainfall infiltration, saturated-unsaturated seepage occurs, and the seepage field changes at the time of continuous rainfall, and the seepage field and stress field jointly determine the slope stability. The existence of pore water pressure has an effect on the strength of fractured rock mass. By reducing the angle of internal friction, cohesion, bulk density and elastic modulus of fractured rock mass, the safety factor is obtained. It is concluded that rainfall is the main factor inducing rock slope to lose stability.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU45

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