成兰铁路松潘段泥石流灾害风险评估

发布时间：2018-02-25 21:35

本文关键词： 成兰铁路松潘段泥石流危险性评价易损性评价风险评价FLO-2D 模型　出处：《成都理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：成兰铁路起于四川省成都市,向北延伸连接至甘肃省境内拟建兰渝铁路的哈达铺站,与甘肃省兰州市相连,是连通我国西南和西北的区域干线铁路中的重要一支。成兰铁路松潘段处于川西高原和四川盆地过渡地带,沿线多处泥石流发育,对区段内铁路建设和运营构成威胁。本文结合成兰铁路松潘段线路选线设计和野外现场调查数据,针对此区段内12条对铁路工程构成直接威胁的泥石流流域,运用数学理论模型、GIS技术和数值模拟等计算分析手段,分别从区域和单沟两方面着手对铁路工程泥石流风险评估进行了研究,以建立较为系统的铁路泥石流风险评估方法体系。通过对研究区内图像资料、地形地质数据、降水资料和泥石流野外调查数据的总结整理,分析了沿线泥石流主要类型和发育分布特征。参考前人对泥石流危险性评价研究和根据泥石流致灾机理,本文选取了泥石流规模、泥石流爆发频率、沟域面积、主沟长度、流域最大高差、主沟平均比降、流域切割密度、松散固体物质储量、堵塞系数、泥沙补给段长度比10个评价因子构建了泥石流危险性评价指标体系,并依次对其取值及进行标准化和规范化。利用熵权法确定泥石流危险性评价指标权重,建立了泥石流危险性评价模型,并依据危险性分级标准,得出沿线泥石流危险性分布图和泥石流危险性路段分区图。由于成兰铁路松潘段目前正处于在建阶段,本文尝试从铁路工程设施遭受泥石流后其自身发生损毁的难易程度出发进行铁路工程易损性评估。从铁路工程选址因素、工程建设规格与结构因素和泥石流灾害特征三方面选取8个评价因子作为铁路工程易损性评价指标,并依据层次分析法计算出各评价指标权重值,结合集对分析理论建立铁路工程设施易损性评价模型,计算出各泥石流发育路段铁路工程设施易损值。最后依据铁路工程设施易损性分级标准,得出沿线泥石流铁路工程易损进行分区图。结合得出的沿线泥石流的危险性评估易损性成果,据泥石流灾害风险评价模型即“风险度(R)=危险度(H)×易损度(V)”,对沿线铁路泥石流进行风险评估,得出成兰铁路松潘段沿线泥石流风险分布图,结果显示沿线泥石流风险主要为低度和中度风险级别,由此此区段内铁路选线设计较为合理。文中选取东龙沟泥石流作为典型沟进行单沟风险性评价,基于FLO-2D模型在取得不同重现周期下数值模拟参数的基础上对东龙沟泥石流重现周期为50年一遇和100年一遇下的泥石流体运用堆积过程进行模拟,获取在两种重现周期下的泥石流体流深和流速的分布情况。以流深与流速的乘积为泥石流强度因子对东龙沟进行了泥石流体强度分区,并在此基础上结合重现周期得到东龙沟泥石流危险性分区图;依据Jakob等学者研究成果泥石流建筑易损函数及易损曲线对东龙沟泥石流堆积区域进行了易损性分区,铁路基础设施工程和镇江关车站主要位于低易损性区域;将东龙沟泥石流危险性分区与易损性分区进行叠加分析,得到东龙沟泥石流风险区划图,结果显示成兰铁路在东龙沟沟口区域区段位于中风险性区域,其余位于东龙沟泥石流危险范围的铁路线路和镇江关车站则位于低风险区域。对于东龙沟泥石流风险分析,两套风险评价方法所得结果显示其风险等级为中度风险,尽管基于数值模拟的单沟风险分析结果中有部分铁路工程处于低度风险区域,但是总体上二者评价结果基本能够对应吻合,从而能够验证此两套方法评价结果有效度是可取的。
[Abstract]:Chenglan railway starts from Sichuan Province, Chengdu City, Gansu Province, north extension connected to the Lan Yu railway Hadapu station, connected with the Gansu city of Lanzhou Province, is communicated with the southwest China and northwest regional trunk railway. As an important branch of the Lanzhou railway section of Songpan in the transition zone of Western Sichuan Plateau and the Sichuan Basin, along mudslides pose a threat to the development, construction and operation of the railway section. Based on the Chenglan railway Songpan section line design and field survey data, in section 12 constitutes a direct threat to the debris flow of railway engineering domain, using mathematical model, GIS technology and numerical simulation calculation analysis method. Respectively from the two aspects of regional and single channel of Railway Engineering debris flow risk assessment study was carried out to establish the risk assessment method system of railway debris flow systematically. Based on the study area Image data, geological data, precipitation data and field survey data of debris flow are summarized, analyzed the main types and distribution characteristics of debris flow along the development. With reference to the former on the debris flow risk assessment research and according to the mechanism of disaster caused by debris flow, the debris flow scale, debris flow frequency, gully area, main gully length, watershed the biggest difference, the average main channel slope, valley cutting density, loose solid material reserves, blockage coefficient, sediment supply length ratio of 10 evaluation factors to construct the debris flow risk assessment index system, and in turn to its value and standardization. To determine the debris flow risk assessment index weight by entropy method and the establishment of a debris flow risk assessment model, and on the basis of risk classification standard, concludes that the debris flow hazard distribution and debris flow hazard zoning map. Because the road Chenglan railway section of Songpan is currently in the construction phase, this thesis attempts to railway engineering vulnerability assessment of the degree of difficulty from the railway engineering facilities damaged by debris flow after its occurrence. The railway engineering construction specifications and location factors, structural factors and debris flow characteristics of the three aspects selects 8 evaluation factors as vulnerability assessment the index of railway engineering, and based on the analytic hierarchy process to calculate the weight value of each assessment index, combined with the railway engineering facilities vulnerability evaluation model set pair analysis theory to calculate the debris flow development road railway engineering facilities. Finally based on the vulnerability value of vulnerability classification standard of railway engineering facilities, draw along the railway engineering vulnerability zoning map of debris flow the combination of risk. The assessment results along the debris flow vulnerability, according to the risk assessment of debris flow disaster risk model "(R) = The risk degree of vulnerability (H) * (V), to evaluate the risk of debris flow along the railway, the Chenglan railway Songpan section along the debris flow risk distribution map shows along the debris flow risk is mainly low and moderate risk level, so this section of railway line design is reasonable. As a typical single ditch ditch risk evaluation of debris flow ditch the East, based on the FLO-2D model in the basis of numerical simulation of different return cycle parameters on Donglong gully debris flow using the return period for 50 years and 100 years of accumulation process was simulated, the distribution of access flow depth and velocity of debris flow in two kinds of reproduction cycle the product to flow depth and velocity for debris flow intensity factors of debris flow intensity area on the Donglong ditch, and on this basis with the return period by Donglong gully mud rock Liuwei Risk zoning map; according to Jakob research results of debris flow vulnerability and fragility curves of the building function Donglong gully area of the accumulation of vulnerability zoning, railway infrastructure projects and Zhenjiang station located mainly in the low vulnerability area; the Long Gully debris flow risk zoning and vulnerability zoning overlay analysis, get the debris flow risk zoning results show Donglong map, is located in the Chenglan railway risk area in the gully region Donglong section, the rest is in the range of dangerous Donglong gully railway line and Zhenjiang station is located in low risk area. Analysis of debris flow risk for long, two sets of risk assessment results show that the risk rating of moderate risk, though based on the analysis of single channel risk and the results of numerical simulation are part of Railway Engineering in low risk area, but overall the two rating The value of the two methods can be basically matched, thus it is advisable to verify the effectiveness of the evaluation results of the methods.

【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U212.2;P642.23

【参考文献】