梯度温度作用下装配式混凝土箱梁温度应力分析

装配式混凝土箱梁在温度作用下产生的结构次内力是造成其开裂的重要因素.为研究装配式混凝土箱梁在梯度温度作用下的温度应力分布,对4种不同国家设计规范梯度温度模式下装配式混凝土箱梁温度场进行分析.通过建立某五跨装配式混凝土箱梁实体单元模型,施加温度荷载,对不同温度场下连续装配式混凝土箱梁的应力与变形进行计算.结果表明,装配式...

Temperature Stress Analysis of Prefabricated Concrete Box-girder under Temperature Gradient

The secondary internal force of the prefabricated concrete box girder under the action of temperature is an important factor causing its cracking.Temperature field of the prefabricated concrete box girder under the gradient temperature mode of four national design codes was analyzed in order to research the distribution of temperature stress of the prefabricated concrete box girder under the effect of gradient temperature.The stress and deformation of a continuous prefabricated concrete box girder under different temperature fields were calculated by applying temperature load on a solid element model of a five-span prefabricated concrete box-girder bridge.The results indicate that the assembled concrete box girder generates secondary internal forces under the action of gradient temperature.The temperature effects produced by standardized temperature models of various countries in concrete box beams vary greatly.The maximum longitudinal stress is measured at the loweredge of the top slab of the box girder,and the maximum difference under different working conditions is 71%;the maximum transverse stress is measured in the concrete bridge deck,and the maximum difference under different working conditions is 113.8%;the maximum main tensile stress of the whole bridge is measured at the secondary side span,and the maximum difference is 66.7%under different working conditions.The influence of the most unfavorable gradient temperature on the fabricated concrete box girder bridge should be considered in the design to avoid the tensile stress exceeding the limit value.