风环境对大体积混凝土桥塔施工水化热的影响分析  

Influence analysis of wind environments on hydration heat of massive concrete pylon construction

作　　者：熊文[1] 尤吉[2] 房涛[2] 叶见曙[1] 易岳林[2] 

机构地区：[1]东南大学交通学院,南京210096 [2]安徽省高速公路控股集团有限公司,合肥230088

出　　处：《东南大学学报（自然科学版）》2015年第5期941-946,共6页Journal of Southeast University：Natural Science Edition

基　　金：交通运输部建设科技资助项目(2014318J14250);安徽省交通科技资助项目(wdky-2013-01);江苏省自然科学基金资助项目(BK2012343)

摘　　要：采用数值模拟结合现场监测的方法研究了复杂风环境对跨江、跨海大桥大体积混凝土桥塔施工水化热的影响.首先,提出了风环境下混凝土水化热的理论计算方法,并基于实际背景工程考虑风环境,对大体积混凝土桥塔施工过程中的水化热效应进行数值模拟;然后,利用现场实际监测数据,对模拟的准确性进行验证;最后,利用此数值模型,针对风特征及结构参数进行分析.分析结果表明:环境平均风速增大会使混凝土桥塔节段内的水化热温度极值降低,但其表面温度梯度增加,开裂可能性也相应增大;结构尺寸的增大会削弱风环境对混凝土水化热的影响,但由尺寸增大引起的刚度增加会导致水化热最大主拉应力明显增大,从而引起混凝土开裂;同一风环境下,桥塔截面形式的改变对浇筑过程中结构内部温度梯度、极值分布以及主应力大小影响明显.The influence of complex wind environments on hydration heat of massive concrete pylon of bridges crossing over river or sea is investigated by using numerical simulation and on-site monitoring.First,the theoretical calculation method of hydration heat of concrete in wind environments is proposed.With the consideration of wind environments,the hydration heat effects in the construction of massive concrete pylon are simulated based on a practical project.Then,the accuracy of the proposed simulation is verified according to the monitoring data from the pre-installed sensors.Finally,the wind characters and structure parameters are parametrically analyzed by using the proposed simulation.The analysis results show that with the increase of the average wind speed,the limit values of the hydration heat-induced temperatures inside the concrete pylon segments decrease,but the temperature gradient of the structure surface and the cracking possibility increase.The influence of wind environments is weakened with the increase of the size of the pylon cross-section.However, the increased structure stiffness caused by the increase of the size can increase the maximum principal tensile stress induced by hydration heat,which results in the concrete cracking.The temperature gradient,the distribution of the limit values of the temperatures,and the principal tensile stress during the construction are highly influenced by the variation of the shape of the pylon cross-section in the same wind environments.

关 键 词：桥塔施工 风环境 水化热 数值模型 参数分析 

分 类 号：U442.59[建筑科学—桥梁与隧道工程]