一般大气环境中混凝土桥梁长期受力性能分析

Long term Mechanical Performance Analysis of Concrete Bridges in Atmospheric Environment

摘要:

一般大气环境中混凝土桥梁性能衰变与碳化和受力作用引起的材料损伤有较大的相关性.为定量分析这两种作用对混凝土桥梁长期性能的影响，总结归纳了材料损伤的数学模型，建立了混凝土桥梁长期性能演变分析方法，并编制了相应的有限元程序.以一座预应力混凝土简支梁为分析对象，研究模型梁在一般大气环境下的长期性能演变规律.结果表明，碳化作用和受力作用均对桥梁长期性能产生明显的影响，使截面有效受力面积减少，结构受力性能衰变；综合考虑碳化作用和受力损伤时跨中断面的截面损失率、挠度和抗弯承载力退化均大于仅考虑碳化作用时的情况.

Abstract:

Performance degradation of concrete bridges in atmospheric environment is closely related to material damage caused by carbonation and forces. In order to evaluate quantitatively the effects of the two actions, the authors summarized the material damage models. Besides, the method for analyzing long term evolution of the concrete bridge performance was proposed and a finite element program was written in this paper. A prestressed concrete simply supported beam in atmospheric environment was investigated. The results show that both carbonation and forces have significant effect on the long term performance of the bridge, which include the loss of the cross section area and deterioration of the mechanical behavior. When considering the effects of carbonation and mechanical damage, the section loss, deflection, and degradation of flexural capacity at the mid span were more serious than those when only carbonation effect was considered.