Research On Reinforcement Of Ultra-low-height Prestressed Concrete Beam On Shuohuang Railway Under Heavy Haul Transport

Heavy haul transport is the most economical and effective mode of transportation with largetransport capacity, high efficiency, and low transportation costs,one of the major trends forShuohuang railway freight transportation is developing heavy haul transport,while the wagonaxle load should be30-ton and more. This paper selects24m-span and32m-spanultra-low-height prestressed concrete simply supported T beam as research object to study thebearing behavior and reinforcing technology under the30-ton heavy haul transport.The calculation shows the ultra-low-height T beam can not meet the requirement of theexisting code of railway bridge under the CHINA-LIVE LOAD because of the increasing secondphase dead load and the changing of parameter of the code. Meanwhile the bearing behavior andthe stiffness of the beams can not meet the requirement of the existing code of railway bridgeunder the1.2times of the ZH (CHINA-LIVE-LOAD(2005)) live load, and adverse effect on thetrain operation safety can be caused,so the reinforcement for the strength and stiffness of beamsto meet heavy haul transport is needed;However it is difficult to reinforce the beam since theultra low height.Through compare with several reinforcement methods,select the method of pushing uppre-bend steel beam,the original concrete beam and the pre-bend steel beam form compositestructure to share live load according to stiffness,meanwhile,the deflection of the compositestructure is equality under service load.Considering the effect of actual E(modulus of elasticity)and I(moment of inertia of cross-section) and the same de flection,so the share-live-loadreduction coefficient of pre-bend steel beam is advanced to achieve the actual bearing behaviorof the original concrete beam. Furthermore, through pushing up the pre-bend steel beam toreduce stress of the original concrete beam is feasible.The reinforcement method of pushing up pre-bend steel beam for24m-span and32m-spanultra-low-height prestressed concrete simply suppo rted T beam can advance the strength andstiffness to meet the the requirement of the existing code of railway bridge unde r the1.2times ofthe ZH live load,and the reinforcement effect adapts to the heavy haul transport of ShuoHuang.