保护层厚度对刚构桥跨中底板的影响

摘要

Aiming at the cracking and lack of durability of mid-span bottom plate of continuous rigid frame bridge, based on the current specification, the solid model of continuous rigid frame is established by using Midas FEA program.Adjusting the thickness of protective layer of bottom plate of the mid-span cross section, its influence on bearing capacity of continuous rigid frame is analyzed;the thickness of the protective layer under the reasonable stress state is obtained, and then compared with the thickness of the protective layer calculated according to the carbonization theory.Taking Shaanxi Province as an example, it is suggested that the thickness of protective layer of continuous rigid frame bridge across section bottom plate should be increased by 5mm on the basis of the minimum specification.%针对连续刚构跨中底板开裂及耐久性不足的问题,在现行规范规定的基础上,主要通过Midas FEA建立连续刚构桥梁跨中实体模型,调整跨中截面底板保护层厚度,分析其对桥梁整体承载能力的影响,得出较合理受力状态下的保护层厚度值,再与碳化理论计算出的符合耐久性标准的保护层厚值进行比较,以陕西地区为例,建议连续刚构桥跨中底板保护层厚度在设计时应该在规范最小值的基础上增加5mm进行参照,其他部位亦可借鉴参考.