跨海钢箱梁桥合龙过程瞬态温度效应分析  

Refined analysis on transient temperature effect during closing process of cross-sea bridge

作　　者：骆佐龙 邓美林 董峰辉 冯仕鹏 LUO Zuolong;DENG Meilin;DONG Fenghui;FENG Shipeng(School of Electric Power,Civil Engineering and Architecture,Shanxi University,Taiyuan 030031,China;College of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]山西大学电力与建筑学院,太原030031 [2]南京林业大学土木工程学院,南京210037

出　　处：《建筑结构》2024年第23期97-104,共8页Building Structure

基　　金：山西省自然科学基金面上项目(202203021221025);山西省高等学校科技创新项目(2021L010、2021L013);中央高校基本科研业务费专项资金资助项目(300102213522)。

摘　　要：为研究外海水域跨海桥梁建造过程中瞬态温度效应,以港珠澳大桥——跨越崖13-1气田管线桥为工程背景,采用理论研究与数值仿真相结合的方法对其合龙过程中在热带强日照辐射、大气对流状态下的瞬态温度梯度及其响应进行精细化分析与预测。首先建立日照辐射与大气对流作用下主梁外表面统一热流密度偏微分方程,求解得到主梁外表面任一时刻等效综合温度;其次建立主梁截面热传导数值分析模型,求解截面瞬态温度梯度分布,并与实测温度梯度数据进行对比验证;最后计算主梁合龙过程中在瞬态温度梯度作用下的温度效应。研究结果表明:跨越崖13-1气田管线桥的瞬态温度梯度预测值与实测值一致(最大偏差小于2℃),且预测值稍大于实测值,使结构偏于安全。合龙过程中主梁温度梯度具有明显的非线性特征:在距离顶板顶面0.4m范围内,温度梯度较高,而在0.4m以外,温度梯度逐渐趋于0。主梁最佳合龙时段为合龙当天晚上21:00至第二天上午6:00,对于最佳合龙时段合龙口两端存在微小转角的问题,可采取设置临时调位千斤顶及施加临时配重的方式加以消除。In order to study the transient temperature effect during the construction of the cross-sea bridge off the coast,based on Hong Kong-Zhuhai-Macao Bridge-Pipe Bridge Crossing Cliff 13-1 Gas Field,the refined analysis of transient temperature gradient and prediction,as well as structural response were conducted under the conditions of strong solar radiation and atmospheric convection during closing process using the method of combining theoretical research and numerical simulation.Firstly,the partial differential equation of uniform heat flux density on the outer surface of the main girder under the action of solar radiation and atmospheric convection was established,and the equivalent comprehensive temperature at any time of the main girder was obtained by solving the equation.Secondly,the transient temperature gradient of the main girder section was obtained by establishing a numerical analysis model of the heat conduction,and the result was verified in comparison with the measured data.Finally,the temperature effect under transient temperature gradient of the main girder during closing process was calculated,and the corresponding construction control measures were discussed.The research results show that the prediction value of the transient temperature gradient is consistent with the measured value(the maximum deviation is less than 2℃),and the predicted value is slightly larger than the measured value,which makes the structure safer.During the closing process,the temperature gradient of the main girder has obvious non-linear characteristics:the temperature gradient is relatively high within 0.4m from the top surface of the roof,while tending to zero outside 0.4m.The best closing time of the main girder is from 21:00 in the evening of the closing day to 6:00 am of the next day.For the small angles at both ends of the closure segment during the best closing time,Temporary adjustment jacks and temporary counterweights can be adopted to eliminate the small angles at both ends of the final closure.

关 键 词：港珠澳大桥 桥梁工程 瞬态温度效应 桥梁合龙 跨海桥梁 精细化分析 

分 类 号：TU391[建筑科学—结构工程] U442.5[建筑科学—桥梁与隧道工程]