大跨径悬索桥承重构件公路火灾安全距离研究  

Safety distance for bearing members of long-span suspension bridge in highway fire

作　　者：李利军[1,2] 董晓明[3] 胡兆同[2] 

机构地区：[1]山东建筑大学交通工程学院,山东济南250101 [2]长安大学公路学院,陕西西安710064 [3]鲁东大学土木工程学院,山东烟台264025

出　　处：《广西大学学报（自然科学版）》2014年第4期886-893,共8页Journal of Guangxi University（Natural Science Edition）

基　　金：交通运输建设重大科技专项(2011318223170)

摘　　要：为研究公路火灾对大跨径悬索桥带来的影响，弥补悬索桥火灾研究的空白，结合结构火灾分析的特点，确定选择间接耦合法进行热-结构耦合分析。以300 MW 车辆火灾为例，运用 ANSYS 有限元程序，建立了悬索桥不同断面的火灾坐标模型，在总结国内外火灾研究工作的基础上，基于 Ingason H.平方增长模型，以典型的大跨径悬索桥缆索承重构件的公路火灾安全距离为研究对象，以降低工程风险、保证大跨径悬索桥结构的安全性和稳定性为研究目标，对大跨径悬索桥吊索和主缆安全距离进行数值模拟，提出了适用于公路火灾研究的热释放率数学模型；建立了公路火灾的物理模型并确定了公路火灾燃烧热源的尺寸和单位面积释热率；并通过热-结构耦合分析，确定了公路火灾下悬索桥吊索和0.4~1.0 m 范围内不同直径主缆的安全距离。研究成果可为今后大跨径悬索桥的抗火设计提供科学依据。In order to study the influence of highway fire on long-span suspension bridges and fill in the blank of suspension bridge fire research, combining structure fire analysis, an indirect coupling method was chosen to carry out the thermal-structure coupling analysis. Taking a 300 MW vehicle fire as an example, ANSYS was used to build the fire coordinate model of different section of a typi-cal suspension bridge. On the basis of fire research domestic and abroad, basing on the Ingason H. square growth model and taking the safety distance for cable bearing component of the long-span sus-pension bridge in highway fire as a research object, a numerical simulation for the safety distance of suspender cable and main cable was performed to reduce project risk and ensure the safety and sta-bility of the bridge. A thermal release rate mathematical model which suits highway fire study was put forward; The safety distance model in highway fire was established, and the size of combustion heat source and heat release rate of unit area were determined; With the thermal-structure coupling analysis, the fire safety distance for suspender cable and main cable of different diameters （0. 4 ~1. 0 m） were determined. The research results can provide some scientific basis for the fire resist-ance design of long-span suspension bridges.

关 键 词：桥梁工程 悬索桥 吊索 主缆 公路火灾 安全距离 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]