基于行车危险性分析的桥梁网络地震易损性研究

发布时间：2018-04-02 04:01

本文选题：PSHA　切入点：行车安全性　出处：《西南交通大学》2017年硕士论文

【摘要】：桥梁的地震响应危及行车安全,就一片路网而言,桥梁结构作为路网的一个节点,其可通过性影响着整个路网的连通可靠度,从而制约着相应机构的对灾害的预防和灾后救援与重建的决策。本文通过我国西南地区的覆盖三个烈度区域的XX路网为例,通过PSHA的方法确定地震参数去衡量桥梁的地震响应,从而得到桥梁结构基于行车安全的易损性曲线。通过Order-X算法确定整片路网在不同重现期下的连通可靠度,这就是路网地震易损性。该曲线在交通路网的震前预防和震后性能预测上具有指导意义。本文首次将地震危险性分析、基于行车安全的桥梁易损性和路网连通可靠度这些理论结合成一个整体,形成了一套对地震灾害的预防与救援都有着重要指导意义的大型框架。在计算上,针对每个场地考虑39个地震重现期,通过PSHA方法确定场地的目标反应谱,以此作为基础进行足够数量的人工波的合成。分别采用1-DOF模型和X Luo算法计算桥梁在地震作用下基于行车危险性的易损性,并把这些桥梁作为路网中的节点计算整片路网的连通性能。同时从结构破坏角度和行车安全两个指标去对比了整片路网的连通程度上的区别。从计算结果可以得出如下结论:1.计算的连通可靠度可作为铁路路网的灾害预防和抗震救灾方案的制定依据。2.随着超越概率的不断增大(即地震发生的越频繁),两种方法下桥梁基于行车安全的易损性不断降低。但X Luo方法所得结果总是低于1-DOF模型,这就表明后者是更为严格的判断准则。3.随着重现期的增大,整片路网的连通可靠度不算降低,但是基于1-DOF模型计算的连通程度总体上都比较低,这表明无论什么级别地震发生时,保守的做法是都不适合行车;而X Luo方法计算结果显示低水平的地震发生时,路网仍然是连通的,但在一定区间上,连通程度迅速降低,此时应采用其他形式进行抗震救灾。4.由于铁路属于轨道交通,行车安全问题相比较结构破坏问题而言,更值得关注,对于铁路路网而言,应该从行车安全角度制定相关决策。
[Abstract]:The seismic response of bridges endangers the safety of traffic. As far as a road network is concerned, bridge structure, as a node of the network, can affect the reliability of the whole network by its passability. Therefore, the decision of disaster prevention and post-disaster rescue and reconstruction is restricted by the corresponding organization. This paper takes the XX road network covering three intensity areas in southwest China as an example, and determines the seismic parameters by means of PSHA method to measure the seismic response of the bridge. Thus, the bridge structure is based on the vulnerability curve of traffic safety, and the reliability of the whole road network under different recurrence periods is determined by Order-X algorithm. This is the seismic vulnerability of the road network. The curve is of guiding significance in the pre-earthquake prevention and performance prediction of the traffic network. The seismic hazard analysis is the first time in this paper. The theory of bridge vulnerability and network connectivity reliability based on traffic safety is integrated into a whole, forming a set of large-scale frame which has important guiding significance for earthquake disaster prevention and rescue. Considering 39 earthquake recurrence periods for each site, the target response spectrum of each site is determined by PSHA method. 1-DOF model and X Luo algorithm are used to calculate the vulnerability of bridges under seismic action based on traffic hazards. These bridges are used as nodes in the network to calculate the connectivity performance of the whole road network. At the same time, the difference of connectivity degree of the whole network is compared from the point of view of structural failure and traffic safety. The calculated connectivity reliability can be used as the basis for disaster prevention and earthquake relief schemes of railway network. 2. With the increasing of transcendence probability (that is, the more frequent earthquakes occur, the bridge under two methods is based on. The vulnerability of traffic safety is decreasing, but the result of X Luo method is always lower than that of 1-DOF model. This indicates that the latter is a more strict criterion. 3. With the increase of the recurrence period, the connectivity reliability of the whole network is not reduced, but the connectivity based on the 1-DOF model is generally low. This shows that no matter what magnitude earthquake occurs, the conservative approach is not suitable for driving, while the X Luo method shows that the road network is still connected when the earthquake occurs at a low level, but the connectivity decreases rapidly in a certain range. At this time, other forms of earthquake relief should be adopted. 4. Because the railway belongs to rail transit, the problem of driving safety is more worthy of attention than the structural damage problem. For the railway network, the relevant decision should be made from the angle of traffic safety.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U442.55

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