大跨径连续刚构桥箱梁日照温度效应分析

Analysis of Sunshine Temperature Effect of Box Girder for Large-span Continuous Rigid Frame Bridge

文章对某高墩大跨径预应力混凝土连续刚构桥箱梁截面温度场进行实测,获得了箱梁竖向温度梯度与横向温度梯度的非线性分布拟合曲线,并采用有限元软件MIDAS/Civil对实测竖向温度梯度模式和竖向与横向的组合温度梯度模式进行仿真分析。研究表明:其位移大小及分布规律基本一致,但在组合温度梯度模式下部分箱梁底板拉应力较大,使得截面抗裂性降低,在设计时应充分重视。

This article measures the actual temperature field of box girder section in a high-pier large-span prestressed concrete continuous rigid frame bridge,obtains the nonlinear distribution fitting curve of the vertical temperature gradient and the lateral temperature gradient of box girder,and uses the finite element software MIDAS/Civil to simulate and analyze the measured vertical temperature gradient mode and the combined vertical and horizontal temperature gradient modes.The research shows that its displacement size and distribution law are basically the same,but the bottom plate of some box girders has larger tensile stress under the combined temperature gradient mode,thus causing the lower crack resistance of cross-section,which requires more attention in the design.