Study On Rapid Transverse Reinforcement Of Superstructure Of Light Thin-walled Small Box Girder Bridge

The light thin-walled small box girder bridges in this paper refer to some prefabricated bridges designed and built in the early stage with the goal of reducing the dead weight of the bridge and reducing the engineering cost,whose superstructure is characterized by short box girder height,thin webs,light dead weight,no or few transverse diaphragms between box girders and weak transverse connection,have appeared a series of diseases in the process of operation.Based on the reinforcement engineering example of a light thin-walled small box girder bridge without diaphragms and the requirement of rapid construction,a reinforcement scheme of adding crossgirder between the main girders is put forward.By means of numerical analysis and scale test,the reinforcement effect of different structural parameters and the influence of additional crossgirder on web stress are studied,and the reasonable arrangement and structure are explored,in the hope of providing theoretical support for reinforcement practice.The main work of thesis is as follows:First of all,the common diseases and reinforcement methods of light thin-walled small box girder bridges are summarized,and the reinforcement methods of transverse connection of assembled girder bridges are summarized.On this basis,a transverse reinforcement scheme of adding prefabricated steel truss girders between small thin-walled box girders is put forward,and its connection structure is optimized to meet the requirements of rapid construction.Then,ANSYS finite element software is used to build the finite element models of the bridge before reinforcement,the bridge encrypted flange connection and the bridge reinforced with different structural parameters of steel truss girder.Modal analysis and transverse load distribution calculation of the bridge are carried out to analyze the reinforcement effect of the design and the influence of structural parameters such as different anchorage position,different stiffness,different number and distance of longitudinal bridge direction on the reinforcement effect.Finally,the displacement of the reinforced beam and the local force of the web were analyzed by using the method of scale test and numerical analysis.According to the structural parameters of steel truss girder,such as different anchoring position,different stiffness,different number and distance of longitudinal bridge,the test girder was set up,and the corresponding finite element model was established.The influence of different structural parameters on box girder web was analyzed by the beam displacement and the change of the maximum stress of web,so as to determine its reasonable construction.The conclusion of this paper can provide reference for the transverse reinforcement design of similar Bridges.