Analysis Of Long-Term Performance Of Timber-Concrete Composite Beam Bridge

Timber-concrete composite beam bridge is a new kind of composite beam bridge,which are from wood structure,concrete structure and steel-combined beam bridge.The timber-concrete composite beam bridge using shear connectors to connect the wood beam with the concrete slab.The strength of the two materials is fully utilized by the compression of the beam and the concrete wing.In order to enhance the overall stiffness of the timber-concrete composite beam bridge,the transverse joint and the concrete slab are added in the wood beam to form the superstructure system of the bridge.Although timber-concrete composite structure has been extensively used in the reconstruction and construction of wood buildings abroad,there is still no perfect structure theory system.It is the first time to study the long-term performance of timber-concrete composite beam bridge.In this paper,FEM of timber-concrete composite beam bridge model has been established with Midas Civil.Considering concrete creep and shrinkage,wood mechanical hygroscopic,creep,shear connectors slip,through the period of time for five months of timber-concrete composite beam bridge load test for a long time,get a timber-concrete composite beam bridge cross section in the time-varying deflection and cross section in stress curve.Based on the time-varying curve,the concrete strain creep curve and the strain creep curve of the wood beam are obtained.In Midas finite element model of injured input test have been the strain of concrete creep curve,wooden beams,strain and creep curve of late timber-concrete composite beam bridge creep to get cross section stress and deformation in the long-term growth factor,for timber-concrete composite beam bridge design and construction to provide the reference basis.The specific research results are as follows:(1)Through the long-term load test of timber-concrete composite beam bridge,and then get a time period for five months of composite beam bridge across the cross section time-varying curve,the top section concrete strain in the edge of time-varying curve,wood beam deformation strain curve of time-varying and time-varying curve.(2)Based on cross section in the concrete flange edge of strain curve of time-varying,wood beam deformation strain curve of time-varying and time-varying curve,get a timber-concrete composite beam bridge mid-span cross-section strain of concrete strain and creep curve and beam creep curve.(3)Based on Midas Civil finite element analysis model,obtained the creep curve by experiment,the prediction of creep of timber-concrete composite beam bridge is made,then get the long-term growth coefficient of stress and deflection in cross section.(4)Based on the calculation formula of long-term load effect of cross-section deflection of steel-concrete composite structures,a formula for calculating the long-term load effect of cross-section deflection of timber-concrete composite beam bridge is put forward.