内向环境风对双层悬索桥火灾温度分布的影响研究  

Study on the influence of inward ambient wind on fire temperature distribution of double-deck suspension bridge

作　　者：鲁佳明 张太科 安伟光 宋晓枫 Lu Jiaming;Zhang Taike;An Weiguang;Song Xiaofeng(School of Safety Engineering,China University of Min-ing and Technology,Jiangsu Xuzhou 221116,China;Jiangsu Key Laboratory of Fire Safety in Urban Underground Space,China University of Mining and Technology,Jiangsu Xuzhou 221116,China;Guangdong Bay Area Traffic Construct Investment Co.,Ltd.,Guangdong Guangzhou 510699,China)

机构地区：[1]中国矿业大学安全工程学院,江苏徐州221116 [2]江苏省城市地下空间火灾防护高校重点实验室,江苏徐州221116 [3]广东湾区交通建设投资有限公司,广东广州510699

出　　处：《消防科学与技术》2024年第8期1051-1058,共8页Fire Science and Technology

基　　金：国家自然科学基金(51974298,52374244);中央高校基本科研基金(2021ZDPYYQ004,2023ZDPYRH01);中国矿业大学“双一流”建设自主创新项目(2022ZZCX05K02)。

摘　　要：为了研究双层悬索桥下层发生车辆火灾时高温对上桥面底部关键部位的影响,基于FDS建立典型双层悬索桥火灾数值模型,以上桥面底部温度观测线上的最高温度点为研究对象,分析大型车辆火灾时不同车辆火源功率和常见海面风级内向环境风速对最高温度及偏移距离的影响,并使用量纲分析法建立数学模型。结果表明:当热释放速率在30~200 MW变化,内向环境风速在0.1~6.7 m/s变化时,最高温度与热释放速率成正比,与风速成反比,而最高温度点偏移距离与之相反;无量纲最高温度变化量与无量纲火源功率的0.8次幂呈正比,与无量纲内向风速呈负相关关系;无量纲最高温度点偏移距离与无量纲火源功率呈复杂的对数关系,总体趋势为负相关,与无量纲风速呈非线性递增的对数关系,趋势为正相关。因此,双层悬索桥车辆火灾中火源功率和内向风速对最高温度点的影响是竞争关系,本数学模型可用于桥梁防火设计和火灾现场最高温度点的准确预测。In order to study the impact of high temperature on the key part of the bottom of the upper deck when a vehicle fire occurs in the lower deck of a double-deck suspension bridge,a typical double-deck suspension bridge fire numerical simulation model is established based on the FDS,and the highest temperature point on the temperature observation line at the bottom of the upper deck is taken as the research object to analyze the effect of the different vehicle fire powers and the inward ambient wind speeds of the common sea surface wind level on the temperature and offset distance of the highest temperature point on the tem‑perature observation line in the case of a large vehicle fire.The quantitative analysis method is used to establish mathematical models.The results show that:when the heat release rate varies between 30 and 200 MW,and the inward ambient wind speed varies between 0.1 and 6.7 m/s,the temperature of the highest temperature point on the temperature observation line at the bottom of the upper bridge deck is directly proportional to the heat release rate,and inversely proportional to the wind speed,and the offset distance of the highest temperature point is inversely proportional to the heat release rate;the amount of change of the dimensionless highest temperature is directly proportional to 0.8 power of the dimensionless fire heat release rate and is negatively correlated to the dimensionless inward wind speed;the dimensionless maximum temperature point offset distance has a complex logarithmic relationship with the dimensionless fire source power with an overall trend of negative correlation,and a nonlinear increasing logarithmic relationship with the dimensionless wind speed with a positive trend.Therefore,the effects of fire source power and inward wind speed on the maximum temperature point in vehicle fires on double-deck suspension bridges are competitive,and this mathematical model can be used for bridge fire protection design and accurate prediction of the maximum temperature point at the fi

关 键 词：双层悬索桥 车辆火灾 工程热分析 火灾数值模拟 量纲分析 

分 类 号：X928.7[环境科学与工程—安全科学] TU998.1[建筑科学—市政工程]