混凝土箱梁温度应力三维分析  

Three Dimensional Analyses of Thermal Stresses in Concrete Box-girders

作　　者：彭友松[1] 朱晓文[1] 强士中[2] 

机构地区：[1]江苏省交通科学研究院长大桥梁健康检测与诊断技术交通行业重点实验室,江苏南京210017 [2]西南交通大学土木工程学院,四川成都610031

出　　处：《铁道学报》2009年第3期116-121,共6页Journal of the China Railway Society

基　　金：江苏省交通科学研究计划项目(08y23)

摘　　要：混凝土箱梁的温度应力可以达到或超过活载产生的应力,是导致混凝土裂缝和损坏的主要原因之一。但传统的温度应力计算方法存在较大的误差。本文根据热弹性理论,对箱形梁的温度应力进行三维分析,提出实用计算方法。这种方法在实际计算中,只需对传统的温度应力计算公式进行简单的修正,即可求得考虑应力分量之间耦合关系的混凝土箱梁三维温度应力,简便实用,计算精度明显提高。最后对现行铁路桥梁设计规范有关温度应力的计算方法进行讨论,提出参考意见。该方法可为在铁路混凝土箱梁的设计和施工中采取合理有效的措施控制温度裂缝、提高结构耐久性,提供科学的依据。Thermal stresses in concrete box-girders can be significant in comparison with live load stresses, and contribute considerably to structural cracking and damage. Conventional methods for predicting thermal stresses in concrete box-girders are deficient in accuracy. Based on the theory of thermoelastieity, a new method is developed to accurately predict the thermal stresses in their three dimensional perspective in concrete box-girders. This method takes into account the coupling between the thermal stress components by a simple modification to the conventional methods. It is readily applicable and substantially improved in accuracy. Discussion is conducted on the provisions with regard to the thermal stresses in concrete box-girders in the current code for railway bridge design. Tentative recommendation is proposed for consideration. The method is particularly useful in making reasonable and effective provisions against thermal cracking to secure the durability of railway concrete box-girder bridges.

关 键 词：桥梁 温度应力 热弹性理论 混凝土箱梁 

分 类 号：U441[建筑科学—桥梁与隧道工程]