城市高架桥抗爆性能评估与防护措施研究

发布时间：2018-05-04 14:57

本文选题：城市高架桥 + 爆炸荷载　；参考：《天津大学》2014年硕士论文

【摘要】：改革开放以来,交通系统作为基础建设的重要组成部分发展得尤为迅猛。城市高架桥与快速路的大力发展,大大的提高了交通运输能力,减轻了城市交通压力。然而,恐怖袭击等意外爆炸事故会导致桥梁的损毁。炸弹在桥梁的特殊位置引爆可能会给桥梁整体结构造成巨大破坏,导致城市交通瘫痪,甚至大量人员伤亡与不可估计的经济损失。虽然现阶段国内外对建筑结构抗爆的研究已经取得了较为丰富的成果,但关于爆炸荷载下城市高架桥的相关研究明显不足。因此,研究城市高架桥的抗爆性能评估与防护措施,为城市桥梁的综合防护和抗爆设计提供参考,具有重要的现实意义。本文开展的主要研究如下:1、基于数值模拟提出了爆炸荷载作用下城市高架桥动态响应及其倒塌过程分析方法。首先,分析了城市桥梁爆炸风险源并确定了城市高架桥可能遭受的爆炸荷载。然后,基于有限元软件ANSYS/LS-DYNA建立桥梁、炸药和空气模型;改变炸药的位置和重量,得到爆炸荷载作用下桥梁关键部位的Von-Mises应力分布、位移响应和桥梁的整体破坏形态,并模拟桥梁在爆炸后的损伤及倒塌过程。最后,以3跨1联的匝道桥为研究对象,进行具体的计算与分析。2、参考建筑抗爆设防标准,初步建立了城市高架桥抗爆设防标准。参考城市高架桥的结构特点与抗震设计的相关规定,提出了城市高架桥的抗爆性能评估方法。首先,根据抗爆设防烈度和抗爆防护目标,确定桥梁结构的抗爆防护等级;采用风险分析的方法确定城市高架桥的爆炸风险等级。然后,依据抗爆防护等级和爆炸风险等级,建立城市高架桥的抗爆设防标准。最后,利用数值模拟方法得到爆炸荷载下桥梁的损伤程度,验证桥梁是否达到抗爆设防标准,对桥梁的抗爆性能进行评估。3、对于不满足抗爆性能要求的城市高架桥,提出了适用于城市高架桥的抗爆防护措施。基于城市高架桥自身结构特点和抗爆防护要求将城市高架桥的抗爆防护措施分为抗爆安全性措施与抗爆构造性措施。
[Abstract]:Since the reform and opening up, the traffic system as an important part of infrastructure development is particularly rapid. The development of urban viaduct and expressway greatly improves the transportation capacity and reduces the pressure of urban traffic. However, accidental explosions such as terrorist attacks can cause damage to bridges. Detonation of a bomb in a special location of a bridge may cause great damage to the overall structure of the bridge, resulting in a traffic paralysis in the city, and even a large number of casualties and incalculable economic losses. Although the research on anti-explosion of building structure has made a lot of achievements at present at home and abroad, the research on urban viaduct under explosion load is obviously insufficient. Therefore, it is of great practical significance to study the anti-explosion performance evaluation and protection measures of urban viaducts, which can provide a reference for the comprehensive protection and anti-explosion design of urban bridges. The main research work in this paper is as follows: 1. Based on the numerical simulation, the dynamic response of urban viaduct and its collapse process under explosive load are proposed. Firstly, the explosion risk sources of urban bridges are analyzed and the explosion loads of urban viaducts are determined. Then, based on the finite element software ANSYS/LS-DYNA, the bridge, explosive and air model are established, and the distribution of Von-Mises stress, displacement response and the whole failure pattern of the bridge are obtained by changing the position and weight of the explosive. The damage and collapse process of the bridge after explosion are simulated. Finally, taking the three-span and one-link ramp bridge as the research object, the concrete calculation and analysis .2. and referring to the building anti-explosion protection standard, the anti-explosion fortification standard of the city viaduct is established preliminarily. Referring to the structural characteristics of urban viaducts and the relevant provisions of seismic design, the anti-explosion performance evaluation method of urban viaducts is proposed. Firstly, according to the intensity of anti-explosion fortification and the target of anti-explosion protection, the anti-explosion protection grade of bridge structure is determined, and the explosion risk grade of urban viaduct is determined by the method of risk analysis. Then, according to the anti-explosion protection grade and explosion risk grade, the anti-explosive fortification standard of city viaduct is established. Finally, the damage degree of the bridge under explosion load is obtained by numerical simulation method, and it is verified whether the bridge meets the anti-explosion protection standard, and the anti-explosion performance of the bridge is evaluated by .3. for the urban viaduct which does not meet the requirements of anti-explosion performance, The anti-explosion protection measures suitable for city viaduct are put forward. Based on the structural characteristics of urban viaducts and the requirements of anti-explosion protection, the anti-explosion protection measures of urban viaducts are divided into anti-explosion safety measures and anti-explosive structural measures.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U447

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