Research On Mechanical Properties Of Hollow Slab Girder Bridges Strengthened By Steel Hoops

At the initial stage of economic development,based on the advantages of hollow slab girder bridges,such as simple formwork structure,low construction requirements,and good economy,China built a number of "small hinge joint" prestressed hollow slab girder bridges.With the economic and social development,the structural use function of the early design of the hollow slab girder bridge has changed,and the construction technology defects,as well as the damage,aging,traffic volume increase and other problems under long-term operation,have seriously affected the safety and function of the bridge.It is particularly important to study and discuss the bridge reinforcement methods to promote the bridge emergency reinforcement and daily maintenance.This method can achieve "maintenance without demolition" in the project,and is highly integrated with the concept of "green building,low carbon emission reduction" advocated by modern society.In this paper,the transverse reinforcement of hollow slab girder bridges with steel hoops is tested and studied,and the influence of different parameters on the performance of hollow slab girder bridges strengthened with steel hoops under static and dynamic action is studied by finite element analysis,and reasonable suggestions for strengthening with steel hoops are put forward.Through understanding the current situation,experimental research and numerical simulation methods of bridge superstructure reinforcement research and vehicle bridge resonance research at home and abroad,the following work is mainly carried out in this paper:1.Based on the actual project,the main test bridge span is choosed,the design and test of steel hoop strengthening method is proposed.After analyzing the experimental results,the strengthen effect of steel hoop method and the transverse distribution law of deflection and strain are discussed.2.The correctness of the modeling is verified in many aspects.On the basis,the parameters of the vehicle speed,axle load,vehicle type,motion state and space vehicle model and road roughness and other parameters.The influence of related parameters on the performance of hollow plate girder bridge strengthened by steel hoop method is studied.3.Based on the numerical simulation results,reasonable design suggestions are put forward for the steel hoops of the strengthening method,including the ratio of width to thickness of steel hoops ribs,the distance between ribs,and the thickness of bottom plate,etc.,which will provides reference for engineering practice.