桥梁震前加固对地震灾区快速疏散能力的影响

Effects of pre-earthquake bridge retrofit on the rapid evacuation capacity of disaster areas

地震灾区的紧急疏散能力关系到人民群众的生命安全,是衡量地区应对灾害能力的重要指标。本文研究路网桥梁震前加固对灾区快速疏散能力的影响,以路网最小疏散总时间作为疏散能力的评估指标,提出路网最小疏散总时间的研究方法。方法包含震后桥梁通行能力计算、震后道路交通容量计算、最小疏散总时间计算、抗震加固策略制定以及相应的经济支出计算,再结合交通网络模型进行案例研究。研究表明:本文提出的路网最小疏散总时间计算方法及资金有限情况下的桥梁抗震加固策略具备可行性;桥梁抗震加固有助于提升生命线系统的疏散能力;在本文提出的加固策略下,随着投资的增加,路网系统最小疏散总时间的下降速度逐渐减慢;当投资额超过一定数量时,加固剩余桥梁对路网疏散时间的影响有限。该研究结果可为地区桥梁抗震加固提供指导。

The emergency evacuation capacity of earthquake-stricken areas is related to the safety of people's lives and is an important indicator for the measurement of the flexibility of a region.This work studies the influence of the pre-earthquake retrofit of the pre-earthquake retrofit of bridges on the rapid evacuation capacity of disaster areas.Taking the minimum total evacuation time of a road network as an evaluation index of evacuation capacity,this study proposes a research method that involves the calculation of post-earthquake bridge capacity,post-earthquake road traffic capacity,and minimum total evacuation time.The proposed method also employs an seismic retrofit prioritization and calculates the corresponding economic expenditure.Using a traffic network model for a case study,this work shows that the calculation method for the minimum total evacuation time of a road network and the bridge antiseismic retrofit strategy with a limited budget is feasible.Specifically,the seismic retrofit of bridges can improve the evacuation capability of lifeline systems.With the proposed retrofit strategy,the decreasing speed of the minimum total evacuation time of road network systems slows down gradually as investment increases within a certain amount.The results of this work can provide guidance for the seismic retrofit of regional bridges.