Structural Design And Field Test Study Of Deep Buried Pile Composite Beam And Slab In Qian Chang Chang Railway

In the base of the joist pile slab structure,the composite beam slab structure with deep buried pile add portrait beam.it has the following advantages: since to the four supports of slab,it can effectively reduce the plate bending moment and deflection in the middle of the span,thereby reducing the slab thickness and reinforcement;portrait beam can effectively share the load of the transverse beam,so it can reduce the beam height and reinforcement;the beam and slab pour at the same time,can increase the construction progress,save the time.Since the deep buried pile composite beam and slab structure first used in Railway Subgrade,the research of mechanics and deformation of the structure,the interaction between the characteristics and system structure and foundation are few,so through theoretical analysis,field test and numerical analysis method,and finish following work:(1)Combined with the China Railway Engineering First Design Institute Group Limited company research project "Qian Zhang Chang deep buried piles composite beam slab structure of subgrade",sufficient research of the domestic and foreign research status of the application of pile board structure,introduces the existing design method of pile slab structure,and without considering the conditions of the ground reaction force,and finish the Qian Zhang Chang buried test section of composite beam plate type pile of component size design,internal force calculation and reinforcement design.(2)The field tests are carried out in the Qian Zhang Chang railway DK49+825.8 section of deeply buried piles composite beam slab structure,and get the stress of pile slab structure contact and deformation characteristics,and this safety stage of deeply buried piles composite beam slab structure status were assessed.(3)Combined with the field test data,deep buried simplified mechanical type pile composite beam slab structure calculation model is proposed,considering the effect of ground reaction force,and the internal force of the components were deduced,and compare the calculation of internal force and internal force design and the field test data,the result show that the simplified mechanical model results are more close to the field test data.(4)By establishing the three-dimensional numerical calculation model,analysis the current condition of the pile plank structure and the structure deformation and the size of ground reaction force,and the calculated values were compared with the field test value,so it can validate the rationality of numerical calculation model.Then through the numerical analysis of pile board structure in the condition of train passing,and the safety of the structure is evaluated;also from the simplified calculation model to derive the expressions of stress of the components in this working conditions,the calculated results and numerical calculation results are comparative analysis,which verify the validity of the model derived the simplified formula calculation.