火灾损伤下预应力混凝土桥梁承载性能劣化研究

Study on Bearing Performance Deterioration of Prestressed Concrete Bridges under Fire Damage

为研究火灾损伤对预应力混凝土桥梁结构承载性能的影响规律,通过对某火灾作用下的大跨预应力钢筋混凝土变截面连续箱梁桥进行技术状况检测,根据相关检测结果,计算分析了该桥跨结构在火损前后主梁的抗弯承载力及抗剪承载力劣化情况,探究了在特定荷载下主梁火损前后上、下翼缘的应力分布规律。研究结论可为火损桥梁结构的加固设计提供科学依据。

In order to study the influence of fire damage on the bearing performance of prestressed concrete bridge structure,this paper tests the technical status of long-span prestressed concrete continuous box girder bridge with variable cross-section under the action of a fire,and according to the relevant test results,the deterioration of flexural bearing capacity and shear bearing capacity of the main girder of the bridge before and after fire damage are calculated and analyzed.The stress distribution law of the upper and lower flanges of the main beam before and after fire damage under a specific load is explored.The research conclusions can provide a scientific basis for the reinforcement design of fire-damaged bridge structures.