降水入渗条件下红粘土边坡稳定性研究

发布时间：2019-05-24 08:01

【摘要】：针对红粘土遇水软化的不良工程特性，本文通过降水入渗过程分析和非饱和渗流模拟研究分析了降水入渗对红粘土边坡稳定性影响的作用机理，利用降水影响边坡稳定性的关键因素作为强度双折减法中的折减因子，提出了利用边坡稳定性扰动系数来评价特定环境干扰因素作用下边坡稳定性的思路。文章从红粘土特性出发，研究红粘土抗剪强度随含水量的变化规律，利用fish语言编写强度双折减系数法的算法程序，实现FLAC3D模拟降水过程对红粘土边坡应力分布和抗剪强度影响的动态分析。从降水扰动致使边坡破坏这个方向入手，采用干扰作用的相对大小衡量特定条件下边坡稳定性安全系数。人类经济活动所产生的高陡矿山、道路边坡大多处于活跃阶段，边坡处于各种环境扰动因素的作用之下，各种因素作用的方式不同，对边坡的影响也有差别，但作用效果会累积发展，，随着坡体损伤积累到一定程度，再有一个合适的扰动边坡就有可能出现失稳。边坡的稳定性直接影响到人们的生命财产安全，如何合理评价边坡稳定性状态是我们现阶段面临的重要课题。边坡安全性影响因子众多，单单用一个安全系数评价边坡稳定性是不够合理的。传统稳定性系数以力学平衡为基础，通过抗滑力和下滑力的比值来定义，体现无扰动条件下边坡安全储备的思想。但此方式求得的稳定性系数不能反映边坡破坏的内部机理，也不能反映外界扰动对边坡稳定性的具体影响。随着计算科学的发展，计算机技术已经为我们解决了计算困难，也为我们通过合理的方法模拟边坡破坏提供了可能。对于特定边坡，在特定时期内的主要控制影响因素是明确的、可控的。东露天矿边坡，在其生产过程中，主要控制因素是生产过程中的动荷载、降水、边坡开挖以及地震作用等。从概率的角度来说，他们同时发生作用的可能性是非常小的，这些因素在某一特定时期只有一个或几个同时发生。所以可以针对不同的影响因子分别研究其对边坡破坏影响机理，从而得到特定条件下边坡稳定性系数。大气降水是诱发边坡失稳的主要因素之一，红粘土独特的干缩及遇水软化特性使得红粘土边坡在降水入渗条件下更加容易失稳。因此，本文以东露天红粘土边坡为背景，研究了入渗深度和含水率分别为主控因素的安全性评价因子。通过分析降水量与降水入渗状态的关系，以降水量为宏观控制指标，指导矿区安全生产。
[Abstract]:In view of the bad engineering characteristics of red clay softened by water, the mechanism of the influence of precipitation infiltration on the stability of red clay slope is analyzed by means of precipitation infiltration process analysis and unsaturated seepage simulation. The key factors of precipitation affecting slope stability are used as the reduction factors in strength double reduction method, and the idea of using slope stability disturbance coefficient to evaluate slope stability under the action of specific environmental disturbance factors is put forward. Based on the characteristics of red clay, this paper studies the variation of shear strength of red clay with water content, and compiles the algorithm program of strength double reduction coefficient method with fish language. The dynamic analysis of the influence of FLAC3D simulated precipitation process on stress distribution and shear strength of red clay slope is realized. Starting from the direction of slope failure caused by precipitation disturbance, the safety factor of slope stability under specific conditions is measured by the relative size of interference. In the high and steep mines produced by human economic activities, most of the road slopes are in the active stage, the slopes are under the action of various environmental disturbance factors, the ways of action of various factors are different, and the influence on the slope is also different. However, the effect will accumulate and develop, and with the accumulation of slope damage to a certain extent, there may be instability of a suitable disturbed slope. The stability of slope has a direct impact on the safety of people's lives and property. How to evaluate the stability of slope reasonably is an important issue we face at this stage. There are many factors affecting slope safety, so it is unreasonable to use a safety factor to evaluate slope stability. The traditional stability coefficient is based on the mechanical balance and is defined by the ratio of anti-sliding force to downward sliding force, which embodies the idea of slope safety reserve without disturbance. However, the stability coefficient obtained by this method can not reflect the internal mechanism of slope failure, nor can it reflect the specific influence of external disturbance on slope stability. With the development of computing science, computer technology has solved the calculation difficulties and made it possible for us to simulate slope failure by reasonable methods. For a specific slope, the main control factors in a specific period of time are clear and controllable. In the production process of the slope of East Open Pit Mine, the main controlling factors are dynamic load, precipitation, slope excavation and seismic action in the production process. From a probability point of view, they are very unlikely to work at the same time, and only one or more of these factors occur at the same time at a given time. Therefore, the influence mechanism of different influencing factors on slope failure can be studied respectively, and the slope stability coefficient can be obtained under specific conditions. Atmospheric precipitation is one of the main factors to induce slope instability. The unique dry shrinkage and water softened characteristics of red clay make the red clay slope more prone to instability under the condition of precipitation infiltration. Therefore, the safety evaluation factors in which the infiltration depth and water content are the main control factors are studied in the background of open-air red clay slope east of this paper. Based on the analysis of the relationship between precipitation and precipitation infiltration, precipitation is taken as the macro control index to guide the safety production of mining area.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU446;TU43

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