异型箱梁截面水化热温度效应研究

Study on hydration heat temperature effect of alien box girder

以湘潭市某斜拉拱桥的健康检测项目为背景,建立边跨混凝土箱梁X1号梁段的有限元实体模型计算由水化热引起的温度应力,计算结果显示,腹板与横隔板交界处、翼缘板外侧、底板下缘处的温度应力超过了混凝土的极限抗拉强度,这些区域与施工监控过程中观测到的翼缘板外侧、腹板与横隔板交界处的早期裂缝有较好的吻合性,可以初步判断该裂缝的成因与水化热温度效应有一定的关系。

Taking the heahh detection project of a able-stayed arch bridge in Xiangtan as the background, this paper establishs the finite element entity model of the side span concrete box girder beam＇s No. XI block to calculate the temperature stress caused by hydration heat. The results show that the temperature stress at the junction of the flange plate and the web plate, outside of the flange plale and at the bottom of the floor higher than the ultimate tensile strength of concrete. These areas have good match with the early cracks at the junction of the flange plate and the web plate and outside of the flange plate found in construction monitoring. So we can preliminary determine the cause of the cracks and has a certain relationship with hydration heat temperature effect.