高速公路预应力混凝土连续箱梁桥火灾后承载能力评定

Evaluation on Bearing Capacity of Prestressed Concrete Continuous Box Girder Bridge of Expressway after Fire

对高速公路某座火灾后的桥梁进行检测,通过对火灾现场的调查,了解桥梁构件外观受损情况,对火灾后的混凝土构件进行了初步鉴定评级,对受火损桥孔进行静动载试验,结果表明,火灾对该桥边梁和次边梁表层混凝土和普通钢筋的材料性能以及桥台盖梁(包括支座垫石)、挡块、背墙混凝土性能均产生了一定的影响,结构承载能力有所降低。

The preliminary appraisal and rating on the concrete components after fire are carried out through the detection of a fire-stricken bridge of expressway,the investigation of the fire scene,and the understanding of the appearance damage of bridge components.The static and dynamic load tests on the bridge openings damaged by fire are carried out.The results show that,the fire has a certain impact on the material properties of the surface concrete and ordinary reinforcement of the side beam and secondary side beam of the bridge,as well as the performance of the abutment capping beam(including bearing pad stone),retaining block and back wall concrete,and the bearing capacity of the structure is reduced.