滑坡灾害风险评估方法及其应用研究

发布时间：2018-03-27 10:51

本文选题：危险性　切入点：蒙特卡罗法　出处：《重庆交通大学》2014年硕士论文

【摘要】：滑坡灾害是最为常见的地质灾害，它不仅给人类的生产生活带来威胁，而且对资源、环境、财产等具有严重破坏性。因此，开展滑坡灾害风险评估，评价滑坡发生的可能性以及由滑坡灾害所造成的损失，是滑坡灾害研究的重点课题。已有的滑坡灾害风险评估工作，较多集中于大区域、大面积滑坡区划的研究，而对于局部的、单体的滑坡灾害风险评估则相对较少。事实上，单体滑坡所造成的灾害更为直接，开展对单体滑坡的风险评估研究工作，很有必要。本文选择公路单体滑坡作为研究对象，旨在构建一套适用于公路滑坡风险评估的方法体系，并通过应用完成对重庆万梁高速张家坪滑坡的风险评估。论文的研究工作及取得成果如下： ①研究了滑坡灾害及风险的基本特征，区分滑坡风险研究中的概念，并通过对滑坡风险评估体系的研究，构建了滑坡灾害风险评估框架。 ②运用可靠性分析原理，选用失稳概率作为评价指标，构建了基于蒙特卡罗法的危险性评价模型，，通过建立滑坡年失稳概率与危险性的对应关系，实现危险性评价。失稳概率按天然、地震、暴雨三种工况进行考虑；对于天然工况，选用传递系数法作为状态函数；对于地震工况，则考虑地震力的作用，并将其简化，即把地震动力指向滑坡滑向进行处理，作用于各滑块重心处；对于暴雨工况，针对滑体浸润线难以确定的问题，本文按最不利状态进行考虑，构建了滑坡体在饱和状态下的失稳概率计算模型，并最终实现了滑坡危险性评价。 ③在易损性评价中，由于承灾体种类多，难以逐一进行评价。因此，本文分析了承灾体易损性的影响因素，挖掘其层次性、模糊性的特点，引入了模糊综合评判，并构建了基于模糊评判的易损性评价模型。 ④通过构建的滑坡风险评估方法体系，实现对张家坪滑坡的风险评估，评价结果显示：张家坪滑坡在天然工况下年失稳概率为0.003，属于中度危险；在地震工况下年失稳概率为0.0142，属于高度危险；在暴雨工况下年失稳概率为0.0549，属于极高度危险；承灾体易损性为低易损性。通过计算，张家坪滑坡在天然工况下滑坡总风险为779.39万元，人口年死亡率为0.054人/年；地震工况下滑坡总风险为1055.51万元，人口年死亡率为0.256人/年；暴雨工况下滑坡总风险为1215.84万元，人口年死亡率为0.988人/年；均为不可接受风险，应及时采取风险管理措施，以保证人民财产和生命安全。
[Abstract]:Landslide disaster is the most common geological hazard. It not only threatens the production and life of human beings, but also has serious damage to resources, environment, property, etc. Therefore, the risk assessment of landslide disaster is carried out. Evaluating the possibility of landslide occurrence and the loss caused by landslide disaster is an important subject in landslide disaster research. Most of the existing landslide risk assessment work is focused on the study of large area and large area landslide regionalization, but for the local landslide risk assessment, the single landslide risk assessment is relatively less. In fact, The disaster caused by single landslide is more direct. It is necessary to study the risk assessment of single landslide. In this paper, we select single landslide as the object of study, in order to construct a set of method system suitable for risk assessment of highway landslide. The risk assessment of Zhangjiaping landslide at Wanliang Expressway in Chongqing is completed through application. The research work and the results are as follows:. The main contents are as follows: (1) the basic characteristics of landslide hazard and its risk are studied, and the concept of landslide risk research is distinguished, and the framework of landslide hazard risk assessment is constructed through the study of landslide risk assessment system. Using the principle of reliability analysis and selecting the probability of instability as the evaluation index, a risk assessment model based on Monte Carlo method is constructed, and the corresponding relationship between the probability of annual instability and the risk of landslide is established. Risk assessment is realized. The probability of instability is considered under three conditions: natural, earthquake and heavy rain. For natural conditions, the transfer coefficient method is chosen as the state function. For seismic conditions, the effect of seismic force is considered and simplified. That is to say, the seismic force is directed to the landslide slide direction and acts on the center of gravity of the slider block. For the rainstorm condition, considering the difficult problem of determining the slip body infiltration line, this paper considers the most disadvantageous condition. The calculation model of landslide instability probability under saturated condition is constructed, and finally the landslide risk assessment is realized. 3 in the vulnerability evaluation, it is difficult to evaluate one by one because there are many types of disaster bearing bodies. Therefore, this paper analyzes the influencing factors of vulnerability of disaster bearing bodies, excavates the characteristics of hierarchy and fuzziness, and introduces fuzzy comprehensive evaluation. A vulnerability evaluation model based on fuzzy evaluation is constructed. 4 through the landslide risk assessment method system, the risk assessment of Zhangjiaping landslide is realized. The evaluation results show that the annual instability probability of Zhangjiaping landslide is 0.003 under natural working conditions, which belongs to moderate risk; The annual instability probability under earthquake condition is 0.0142, which is highly dangerous; the annual instability probability under heavy rain is 0.0549, which is extremely dangerous; the vulnerability of disaster bearing body is low vulnerability. The total risk of Zhangjiaping landslide under natural conditions is 7.7939 million yuan, the annual death rate of population is 0.054 person / year, the total risk of landslide under earthquake condition is 10.5551 million yuan, the annual mortality rate of population is 0.256 person / year, and the total risk of landslide is 12.1584 million yuan under heavy rain condition. The annual mortality rate of population is 0.988 person / year, which is an unacceptable risk. Risk management measures should be taken in time to ensure the safety of people's property and life.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U418.55

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