The Research Of Fire Damage Assessment And Reinforcement Methods On Bridge Structure

Concrete bridge has been widely used for its convenient construction,economical construction,convenient maintenance and strong crossing capability.In recent years,the fire incidents of bridge structure occur frequently.The high-temperature action of fire can damage the concrete,ordinary steel bar and prestressed steel bar,at the same time causing damage to the components of the bridge.The fire not only cause great damage to the concrete bridge itself,but also seriously affect the normal operation of transportation.After the fire,timely and reasonable damage assessment of damaged bridges must be carried out,and reasonable reinforcement method should also be designated in order to achieve the restoration of structural carrying capacity and to ensure the smooth road network purposes.This paper is based on a concrete bridge encountered a fire,and the research of fire damage assessment and reinforcement methods on bridge structure are systematically studied.The main results are as follows:(1)Based on the existing research results,the damage characteristics of concrete,ordinary steel bar and prestressed steel bar in fire and after fire are categorized and analyzed from the point of view of the composition of concrete bridge,which provide the basis for the detection and evaluation of concrete bridge encountered a fire.(2)On the basis of understanding the damage characteristics of the concrete bridges,the testing and evaluation procedures for the bridge structures are put forward,and a series of damage detection are carried out for each component of the fire background bridge,which verifies the operability of the evaluation methods and processes.The damage detection scheme proposed in this paper has certain reference value.(3)Several evaluation methods of bridge encountered a fire are studied and analyzed.Aiming at the insufficiency of existing research,a comprehensive evaluation method of the structural performance of the damage concrete bridge is proposed.Meanwhile,the damageassessment process is given and successfully applied to damage assessment of the background bridge.(4)The basic principles of reinforcement and the main reinforcement methods of various components of fire damaged bridges are studied,and the applicability of each reinforcement method is discussed.Finally,the reinforcement scheme of the bridge is proposed and proven safe and reliable according to the theoretical analysis of the background bridge after reinforcement,which provides the basis for the reinforcement and maintenance of the same type of bridge.