Numerical Simulation And Experimental Analysis Of The Deflection Of Concrete Pavements

Concrete slab because of its simple structure, convenient for construction, good performance, get very widely used in engineering, foundation board, precast concrete,rural roads and other projects are using typical example of concrete slab structure.How to evaluate concrete slab work conditions, has become an important topic of concrete engineering practice. In multiple index of the concrete slab structure, the convenient deflection value measurement, convenience of application, are good indicators reflect the status of concrete slab structure. In the concrete slab in the specification, all using deflection value as a control index for evaluation the performance of the structure. So the deflection of the concrete slabs has important engineering application value and practical significance.In this paper, analysis and comparison of existing concrete slab model, two kinds of concrete slab model, theoretical model and finite element model. And by drop hammer type deflection instrument(FWD) test values transformation of beckman beam deflection(BB) measured, calculated result is accordance with the measured values of the two models, the error within the range of acceptable in engineering.Theoretical model of the error between 0.3% ~ 0.3%, the error of the finite element model is between 1.8% ~ 4.8%.Winkler foundation plate model of theoretical model based on the classical static model is set up, BB test vehicles at crawl speed through the simulation of road conditions. This model mainly include: car load is simplified to double circular uniformly distributed load, acting force between foundation and concrete slab for the linear spring force, stiffness coefficient for spring foundation coefficient, concrete slab is simplified to four edges free rectangular thin plate. Through theoretical derivation, the partial differential equation can be concluded that the concrete slab stress. The differential equation of Galerkin method(Galerkin) can be used to solve and determine all can satisfy the displacement boundary and stress boundaryconditions of displacement function, set up a theoretical formula of deflection of the concrete slabs. In order to determine the formula of the coefficient, using MATLAB program was compiled, can be concluded that the results of the theoretical model calculation.Finite element model as well as theoretical model and static model based on Winkler foundation plate model. Of reinforced concrete slabs, the main difference is that: on the processing of theoretical model assumes that it is thin, the finite element model with discrete grid cell. In addition, this paper USES the finite element model to study the change law of deflection under different parameters were. The results show that the load increase, the plate deflection increases; Elastic modulus increases, the plate deflection in decreased; Poisson’s ratio increases, the tendency of increase with the plate deflection is slow; Spring foundation coefficient increases, plate deflection decreases.