大跨波形钢腹板箱梁桥日照温度场及温差效应研究

针对目前我国桥涵设计规范未给出波形钢腹板箱梁日照温度梯度，和其温度梯度研究工作的不足。以港珠澳大桥连接线工程某特大跨波形钢腹板连续箱梁桥为研究对象，对其波形钢腹板箱室断面，进行了3 d的日照温度场观测。研究了其日照温度场分布规律，继而提出波形钢腹板箱梁竖向和横向温度梯度数学计算模型，并对温差参数的取值进行了探讨。结合现场实测数据和有限元软件，对比不同温度梯度模式的温差计算值，分析了其温差效应。研究结果表明:实测波形钢腹板箱梁温度场分布与传统箱梁相差较大；温度梯度模式为指数函数和线性函数组成的分段函数；该模式计算得到的竖向及横向温差值与实测结果十分吻合，其他模式与实测结果相差较大；由于温差效应影响，顶板中轴线下缘产生了较大的横向拉应力，设计中应给予关注。该模式可为不同气候条件地区同类桥梁温度荷载计算提供重要参考。

RESEARCH ON SUN LIGHT TEMPERATURE FIELD AND THERMAL DIFFERENCE EFFECT OF LONG SPAN BOX GIRDER BRIDGE WITH CORRUGATED STEEL WEBS

At present, no solar temperature gradient for the box girder with corrugated steel webs has been found in any codes for design of highway bridges and culverts of China, and the relevant research about the sun light temperature gradient is limited. With this regard, a large span continuous box girder bridge with corrugated steel webs in Hong Kong-Zhuhai-Macao Bridge was taken as an example in the paper, and three-day observation of the sun light temperature field of box girder section with corrugated steel webs was carried out, and then the distribution law of the sun light temperature field was studied. The mathematical models of vertical and lateral temperature gradient of box girders with corrugated steel webs were proposed, and the values of thermal parameters were discussed. According to the data of field test and calculation of finite element software, the values of temperature difference in different temperature gradient models were calculated and the temperature difference effect was comparatively analyzed. The research results show that the temperature field distribution of box girders with corrugated steel webs is significantly different with that of the traditional box girder. The temperature gradient model can be defined by a piecewise function composed of exponential function and linear function. The vertical and lateral temperature difference values of box girders with corrugated steel webs, which are calculated by proposed models, matched well with the measured results. Due to the temperature effect, biggish transveral stress is generated in the lower edge of the top slab around the axis, which should be paid more attention in the design. This temperature gradient pattern can be used as important reference in calculating the temperature loads of the same type bridges in different climatic conditions.