【摘要】 现行规范所规定的验算应力仅是针对一根薄腹窄梁的,并不能反映现代复杂桥梁结构的真实受力情况。设计方法中的验算应力不完整造成了现行规范体系的计算结果存有漏洞和缺失,使得有些常见开裂病害无法从现有设计计算框架中找到答案。列出了一个箱梁结构需要关注的完整的验算应力以及对应的裂缝形式,并且提出完整验算应力的表达方式。空间网格模型能够完整地反映所有的验算应力,是最为全面实用的精细化模型。通过比较空间网格模型和实体模型的计算结果,说明了空间网格模型能反映包括剪力滞效应、薄壁效应和局部效应在内的荷载效应。通过空间网格模型计算得到的混凝土桥梁结构的完整验算应力,可以更完整把握结构受力特征、了解结构中可能出现问题的地方,也可以更确切地分析出现问题的原因以及为解决相应问题提供依据。更多还原

【Abstract】 The checking stresses in the current codes are directed at the thin-web beam,while the whole behavior of the modern complex bridge structures cannot be reflected. The incompleteness of the checking stresses gives rise to the deficiency of the design and calculation. Some frequently-occured cracks in the structure cannot be reflected in the expression of the current checking stresses. The complete checking stresses and corresponding crack shapes of the box girder structure are listed in the paper. By comparing the results from the spatial grid model and solid model,it is found all the concerned stresses of the load effects including the shear lag effect,thin-wall effect and local effect can be obtained by the spatial grid model. The spatial grid model is a practical and precise model to analyze the complete checking stresses. It improves the understanding of the structural behavior and provides the information for analyzing and solving the deficiency in the structure.更多还原