大跨径桥梁施工控制温度应力分析

针对大跨径桥梁施工控制中结构设计参数的变化能导致结构内力的变化和形状的改变,以及与时间有关的温度参数不易确定的问题,在分析了产生温度应力原因的基础上,根据沿梁长的温度分布是均匀的,略去断面局部变化引起的梁体温差分布的微小差别,按单向温差荷载计算应力等基本假定,在给定温度分布的前提下,提出了温度应力实用计算方法,并通过工程实例分析了温度应力对桥梁施工控制的影响。结果表明:考虑温度影响的理论值与实测应力值接近,为工程应用提供了理论依据。

Analysis of temperature stress in control of long-span bridge construction

The variation of the structural design parameters can lead to the change of the internal forces and the alteration of the shape in the control of the long-span bridge construction. Also, the parameters relevant to the time are not easy to be determined. After the analysis of the reasons of bringing about temperature stress,the effective means of computation can be put forward if the distribution of temperature is given. During the course,the following basically presumptions should be in accordance:the distribution of temperature is uniform along the beam; the minute variation of the temperature distribution should be neglected which is the result of the local changes of the beam cross section. The computation of the temperature stress should be according to the single direction load resulted by the difference of the temperature. The influence to the construction of bridges produced by the temperature stress should be studied through the analysis of the actual examples. The result shows that the theoretical values approach to the actual value got by test when the temperature influence is considered,which provides some theoretical reference to the bridge construction.