波形钢腹板PC组合箱梁内衬混凝土部位温度分布研究

Temperature Distribution of Lining Concrete Part of the PC Composed Bridge with Corruagted Steel Webs

波形钢腹板PC箱梁桥内衬混凝土部位的材料不同,在日照作用下,混凝土与钢材部位的温度分布也不同,因此有必要对其腹板温度场进行研究.本文依托宁夏叶盛黄河公路大桥,利用无线采集仪模块和温度传感器,首次开展了波形钢腹板内衬混凝土部位的温度梯度研究.通过对内衬混凝土截面32个测点进行分析,得到混凝土及波形钢腹板的温度变化规律.利用最大极值分布对百年一遇的极端气温进行预测.研究表明:波形钢腹板箱梁的混凝土顶板、底板和内衬混凝土的竖向温度梯度可按照桥梁规范取值即可.腹板的波纹钢和混凝土材料性质不同,在升温时,存在不同的温度梯度;由于太阳辐射原因,波形钢腹板向阳侧和背阳侧温度梯度模式存在差异,在16点时,内衬混凝土部位的波纹钢和内衬的温差沿高度分布规律为:向阳侧呈现正弦曲线分布,背阳侧呈现梯形分布.本研究首次提出的波形钢腹板内衬混凝土部位的温度梯度可以为该类桥梁设计提供参考.

Different materials of the lining concrete part of the PC composite box girder bridge with corrugated steel webs have different temperature distributions of the concrete and steel parts under the action of sunlight,so it is necessary to study the temperature fiel.This paper relies on Ningxia Yesheng Yellow River Highway Bridge,using wireless acquisition instrument module and temperature sensor,studied the temperature gradient of corrugated steel web lining concrete parts for the first time.By analyzing the 32 measuring points of the lining concrete section,the temperature variation of concrete and corrugated steel webs was obtained.The maximum extreme value distribution was used to predict the extreme air temperature once in a hundred years.Studies have shown that the vertical temperature gradient of the concrete roof,floor,and lining concrete of corrugated steel web box girder can be determined according to the bridge specification.The corrugated steel and concrete materials of the web have different properties.When the temperature is raised,there are different temperature gradients.Due to the solar radiation,the temperature gradient patterns of the sunburst and dorsal surface of the corrugated steel web are different.At 4 pm,The temperature difference between the corrugated steel and the inner lining of the concrete lining is along the height distribution:the sinusoidal distribution appears on the sunny side,and the trapezoid distribution appears on the back-yang side.The temperature gradients of the concrete parts of the corrugated steel webs proposed for the first time in this study can provide reference for the design of such bridges.