基于地震危险性的桥梁网络震后运输能力分析

发布时间：2018-01-04 02:44

本文关键词：基于地震危险性的桥梁网络震后运输能力分析　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：交通路网的震后性能对减少区域性灾害损失并加快重建有不言而喻的重要意义。地震发生以后,桥梁结构的损坏会导致部分甚至整个交通路网的中断,严重影响震后救灾工作。本研究初步建立了一套评估流程,可以判断出整个交通路网的可靠程度,有助于为交通路网系统管理者和政府决策部门提供救灾依据。首先,本文运用了概率地震危险性分析方法,模拟震源、路径衰减,并结合桥梁材料参数的随机特性,提出桥墩和支座结构易损性曲线计算方法,继而采用一阶界限法,由桥墩和支座等结构构件易损性曲线建立桥梁系统易损性曲线。然后,根据桥梁系统易损性曲线,评估出桥梁损伤水准和计算交通路网相应路段震后通行能力,结合带有路段能力限制的交通平衡配流模型,提出了一种以出行费用为评价标准的路网易损性计算方法。并分别从地震重现期和路网需求能力比两个因素出发,讨论整个交通路网的易损性变化情况。计算结果表明,这两个因素都对整个路网易损性有一定影响。最后,由于混凝土龄期不足以及构件之间未形成一个整体,所以余震地区桥梁整个施工过程往往存在较大风险。本文基于以往地震发生记录,回归出余震发生概率模型,对桥墩定义开裂破坏、轻微破坏、中等破坏、严重破坏和完全破坏五种损伤指标,提出一种震后桥梁悬臂施工过程易损性计算方法。计算结果表明,整个桥梁施工过程中开裂破坏的超越概率接近40%,而发生完全破坏的超越概率不足5%,因此余震地区震后桥梁施工过程应更加重视轻微等级的损伤。
[Abstract]:The post-earthquake performance of traffic network is of great importance to reduce the regional disaster loss and accelerate reconstruction. After the earthquake, the damage of bridge structure will lead to the interruption of part or even the whole traffic network. This study has established a set of evaluation flow, which can judge the reliability of the whole transportation network. It is helpful to provide disaster relief basis for traffic network system managers and government decision-making departments. Firstly, this paper uses probabilistic seismic hazard analysis method to simulate the source and path attenuation. Combined with the random characteristics of bridge material parameters, the method of calculating the vulnerability curve of bridge pier and support structure is proposed, and then the first-order limit method is adopted. The vulnerability curve of bridge system is established from the vulnerability curves of structural components such as piers and supports. Then, according to the vulnerability curve of bridge system, the damage level of bridges and the post-earthquake capacity of corresponding sections of traffic network are evaluated. Combined with the traffic equilibrium assignment model with section capacity constraints, this paper presents a calculation method of road network vulnerability based on travel cost as the evaluation standard, and starts from two factors, earthquake recurrence period and road network demand capacity ratio, respectively. The results show that these two factors have certain influence on the vulnerability of the whole road network. Finally, due to the shortage of concrete age and the lack of component, a whole is not formed. Therefore, the whole construction process of the bridge in aftershock area often has great risk. Based on the previous seismic records, this paper regressed the probability model of aftershock occurrence, defined the bridge pier cracking damage, slight damage, moderate damage. This paper presents a method to calculate the vulnerability of bridge cantilever construction process after earthquake. The calculation results show that the overstepping probability of cracking and failure in the whole bridge construction process is close to 40%. However, the probability of complete damage is less than 5%, so the construction process of bridge in aftershock area should pay more attention to the damage of minor grade.
【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】：U446

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