滑坡体实时稳定性分析理论研究

发布时间：2018-01-20 07:05

本文关键词： 边坡监测红壤土滑动面剪切面实时稳定性数值分析　出处：《海南大学》2015年硕士论文　论文类型：学位论文

【摘要】：边坡稳定性研究一直是岩土工程领域的重要课题。边坡监测可以最直观地了解边坡的运动状态,也是评价边坡稳定状态的重要依据,因而在边坡工程中逐渐得到了广泛的应用。但当前基于现场监测数据的边坡稳定性判别和预测预报一般还是从分析数据的变化趋势来入手,还未能构建出边坡位移监测数据与滑坡力学稳定机制之间深层次内在关系的研究方法和成果。因此,需加强基于监测数据预测边坡稳定性的理论研究。对海南省部分森林公园的现场考察发现：由于景区内人类活动的加剧(经济作物种植、山体开挖取土、景区道路修建等)和台风强降雨的常年侵蚀和冲刷,使得园区内小型崩塌和浅层滑坡频繁发生。这不仅是对景区内的自然生态环境的极大破坏,同时也是严重的安全隐患。因此,加强这些地区边坡的监测、预报预警及治理是十分必要的。本文结合边坡位移监测信息解析、土体应力状态和应力应变关系分析,提出了基于位移监测数据的边坡稳定性实时计算理论。首先,对海南代表性红壤土进行常规物性试验、不同饱和度下的三轴试验和直剪试验,获得数值理论研究所需的土性指标参数及其变化规律；接着,基于边坡稳定性有限元位移场计算结果提取虚拟深层测斜仪布测点的位移量,根据相邻两监测点的相对位移量计算此段滑动面上的应变,同时对模型中模拟监测点处的土体应力状态进行分析；然后,根据三轴试验应力应变曲线和剪切试验剪力位移曲线定义计算相应剪切面上的剪力和应变,并获得其关系曲线；最后,结合边坡滑动面上实时的应变值和相应应力状态下土样剪切面上的剪力应变曲线,获得边坡滑动面上实时发挥的剪应力值,并与土体剪切强度峰值进行比较,由此来定义边坡的实时稳定系数。本文所提出的实时稳定系数法可构建边坡位移监测数据与滑坡内在力学稳定机制之间的联系,从而实现了边坡稳定性的实时跟踪预测。该方法克服了传统边坡稳定性分析理论中,不能考虑边坡的变形过程,只能计算出单一稳定系数的缺点；和边坡稳定性数值分析相比：实时稳定系数法避免了降雨入渗强度确定、流固耦合分析等难题,直接由滑移面上的位移变形综合反映,降低了边坡实时稳定分析的难度。对比计算表明：实时稳定系数法、传统边坡稳定性和强度折减边坡稳定性数值分析方法三者的结果基本一致,因此本文所提出的上述边坡稳定性实时稳定系数方法在理论上是可行的。
[Abstract]:Slope stability research has been an important subject in the field of geotechnical engineering. Slope monitoring can directly understand the state of slope movement and is also an important basis for evaluation of slope stability. Therefore, it has been widely used in slope engineering. However, at present, slope stability discrimination and prediction based on field monitoring data are generally based on the analysis of the trend of data change. The research methods and achievements of deep relationship between slope displacement monitoring data and landslide mechanical stability mechanism have not been constructed, so it is necessary to strengthen the theoretical study of slope stability prediction based on monitoring data. The site investigation of some forest parks in Hainan Province shows that due to the intensification of human activities (cash crop planting, mountain excavation, road construction, etc.) and the perennial erosion and erosion of heavy rainfall caused by typhoons. It is not only a great damage to the natural ecological environment in the scenic area, but also a serious safety hazard. Therefore, the monitoring of slope in these areas should be strengthened. It is very necessary to forecast early warning and control. Based on the analysis of slope displacement monitoring information and the analysis of stress state and stress-strain relationship of soil mass, the real-time calculation theory of slope stability based on displacement monitoring data is proposed in this paper. The conventional physical property test, triaxial test and direct shear test of Hainan red loam soil with different saturation were carried out to obtain the soil property index parameters and their variation law for numerical theoretical research. Then, based on the calculation results of displacement field of slope stability finite element, the displacement of the measuring point is extracted from the virtual deep inclinometer, and the strain on the sliding surface is calculated according to the relative displacement of the adjacent two monitoring points. At the same time, the stress state of soil at the simulated monitoring point in the model is analyzed. Then, according to the definition of stress-strain curve and shear displacement curve of triaxial test, the shear force and strain on the corresponding shear plane are calculated, and the relationship curves are obtained. Finally, combining the real time strain value on the slope sliding surface and the shear strain curve on the soil sample shear plane under the corresponding stress state, the real time value of the shear stress on the slope sliding surface is obtained. The real-time stability coefficient of slope is defined by comparing with the peak value of soil shear strength. The real-time stability coefficient method proposed in this paper can construct the relationship between slope displacement monitoring data and the inherent mechanical stability mechanism of landslide. Thus the real-time tracking prediction of slope stability is realized. The method overcomes the shortcoming of traditional slope stability analysis theory that the deformation process of slope can not be considered and only a single stability coefficient can be calculated. Compared with the numerical analysis of slope stability, the real-time stability coefficient method avoids the problems of rainfall infiltration strength determination and fluid-solid coupling analysis, and directly reflects the displacement and deformation on the slip surface. The comparison and calculation show that the results of real-time stability coefficient method, traditional numerical analysis method of slope stability and strength reduction slope stability are basically the same. Therefore, the real-time stability coefficient method proposed in this paper is feasible in theory.
【学位授予单位】：海南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.22;TU43

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