沿河路基挡土墙水毁危险性定量化研究

发布时间：2018-10-05 11:31

【摘要】：陕西省山区沿河道路相对较多,因为水毁造成的经济损失每年数值庞大。目前大多数评价道路水毁的方法都以定性评价为主。但是定性评价有其固有的缺点,不能明确的说明水毁的具体风险。本文采用蒙特卡罗的计算方法,运用失效概率的大小和可靠指标定量评价道路水毁。道路水毁的形式多种多样,并且绝大多数沿河公路具有防护工程,本文以常见的由于沿河重力式挡土墙破坏而造成的水毁作为研究对象进行研究。本文首先归纳分析了计算结构失效概率的相关方法。根据对不同计算方法优缺点的对比分析,选取蒙特卡罗模拟法计算沿河挡土墙的失效概率。对影响浸水挡土墙可靠度的随机因素进行了分析,随机因素主要包括挡墙自身因素和挡墙中的水力因素,野外调查和理论分析表明,水流对挡土墙,特别是挡土墙裂缝的动水压力作用是引起挡土墙破坏的关键环节。通过正交试验探究了墙前水流冲击挡土墙产生的脉动压力特征。利用试验数据分析方法比较了脉动压力在裂缝中和墙面的数值分布规律,并分析了墙前脉动冲击力。根据挡土墙的设计原则,分别建立了枯水期和暴雨期挡土墙的抗倾覆,抗滑动和基底承载力稳定性的功能函数。根据功能函数中随机变量的参数分布特征,利用MATLAB软件编制程序实现了浸水挡土墙蒙特卡罗数值模拟实验。对省道102道路进行水毁调研,得到水毁情况和沿河挡土墙相关数据。根据相关数据以及建立的功能函数和MATLAB软件求解沿河挡土墙的可靠指标。结果显示,依托工程挡土墙在枯水时期最容易发生的破坏为滑动破坏,在暴雨洪水时期最易发生的破坏为倾覆破坏。本文通过对沿河挡土墙失效概率和可靠指标的计算,实现水毁危险性评价定量化,并指导当地相关管理部门根据研究成果采取科学合理的预防措施进行防治公路水毁灾害防治,使灾害带来的风险减小。
[Abstract]:There are relatively many roads along rivers in the mountainous areas of Shaanxi Province, because the economic losses caused by water damage are huge every year. At present, most methods of road damage evaluation are qualitative evaluation. However, qualitative evaluation has its inherent disadvantages and can not clearly explain the specific risk of water destruction. In this paper, Monte Carlo method is used to quantitatively evaluate road damage by using the magnitude of failure probability and reliability index. The forms of road water damage are various, and most of the highway along the river have protective works. This paper takes the water damage caused by the destruction of gravity retaining wall along the river as the research object. In this paper, the relevant methods for calculating the failure probability of structures are summarized and analyzed. According to the comparative analysis of the advantages and disadvantages of different calculation methods, Monte Carlo simulation method is selected to calculate the failure probability of the retaining wall along the river. The random factors affecting the reliability of soaking retaining wall are analyzed. The random factors mainly include the factors of the retaining wall itself and the hydraulic factor in the retaining wall. The field investigation and theoretical analysis show that the flow of water plays an important role in the retaining wall. In particular, the hydrodynamic pressure of retaining wall crack is the key to the failure of retaining wall. The characteristics of pulsating pressure produced by the impinging flow in front of the wall are investigated by orthogonal test. The numerical distribution of fluctuating pressure in cracks and walls is compared by means of experimental data analysis, and the pulsating impact force in front of the wall is analyzed. According to the design principle of retaining wall, the function functions of anti-overturning, anti-sliding and stability of foundation bearing capacity of retaining wall during dry season and rainstorm period are established respectively. According to the parameter distribution characteristics of random variables in the function, Monte Carlo numerical simulation experiment of soaking retaining wall is realized by using MATLAB software. The flood damage of provincial highway 102 was investigated, and the data of water damage and retaining wall along river were obtained. According to the relevant data, the function and the MATLAB software, the reliable index of the retaining wall along the river is solved. The results show that the most vulnerable failure of retaining wall in the low water period is sliding failure, and the most prone damage in rainstorm and flood period is overturning damage. Through the calculation of failure probability and reliable index of retaining wall along river, this paper realizes the quantitative evaluation of water damage risk, and instructs the local relevant management department to take scientific and reasonable preventive measures to prevent and cure highway flood disaster according to the research results. Reduce the risk of disaster.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U416.1

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