Study On The Overlay Effect Of Replacement Of Bridge Deck On Bearing Capacity Of T-girder Bridges

With the increase of the operation time,traffic and heavy vehicles,there will be serious diseases such as the decline in performance and even the use function of the deck pavement.Therefore,the design,calculation,use and replacement of the deck pavement should be studied.In the traditional bridge structure design and calculation,the bridge deck pavement and the main structure are not considered together.Only the bridge deck pavement is regarded as the second-stage dead load,and the effect of the deck pavement on the mechanical performance of the main structure is ignored.With the improvement of bridge deck pavement construction technology and the improvement of pavement material performance,the durability of deck pavement is improved,the bond between bridge deck pavement and main beam is strengthened,and the deck pavement is actually involved in structural stress.Therefore,the superposition effect of bridge deck pavement should be considered in the design and calculation of bridge structure.In order to clarify the influence of the bridge deck overlay effect on the bearing capacity of the T-beam bridge,and to rationally use the overlay effects of the bridge deck pavement in the repair and reinforcement of the old bridge,a systematic theoretical study was carried out.First of all,for the study of bridge deck pavement reinforcement method,starting from the reinforcement principle and the ultimate bearing capacity of the structure,it is necessary to analyze the stress conditions during the various stages of construction of the T-beam bridge under the cooperation of bridge deck piling,and to use prestressed composite beams for reference.Based on the calculation model of the bearing capacity,the calculation formula for the bearing capacity of the prestressed concrete T-beam bridge considering bridge deck pavement cooperation was proposed.Secondly,by summarizing the commonly used method for calculation of bridge deck pavement thickness,the influence of overlay effect of deck pavement on the bearing capacity and effect of T-beam is considered,and a theory based on flexural bearing capacity and the stress of longitudinal reinforcement steel are used.The advanced phenomenon controls the calculation method of the bridge deck pavement thickness combined to calculate the reasonable thickness of deck pavement considering the bridge deck overlay effect.Third,on the basis of the calculation method of commonly used load lateral distribution coefficient,the formula for considering the lateral distribution coefficient of bridge deck overlay effect is deduced.At the same time,the finite element software Midas civil was used to establish a full bridge model considering the overlay effects of pavement overlays and the overlay effect without consideration of pavement overlays.The analysis results show that the horizontal distribution of load lines tends to be flat considering bridge deck overlay effects.Surface pavement is conducive to the lateral transfer of the load,so that the load on the main beam of each piece is more uniform.Finally,combined with concrete engineering examples,the static load test of hinged T beam bridge is carried out to test the deformation of cross section and cross section of 1/4 cross section under different working conditions,and the deformation of T beam bridge under various test conditions is calculated with finite element software,and compared with the test value,the deflection changes before and after the bridge deck paving method are used to reinforce the deflection of the T beam bridge.The influence of bridge deck pavement on main girder is obtained,and the effect of bridge deck pavement method to consolidate T girder bridge is verified.