Mechanical Analysis Of Cement Concrete Pavement Under Temperature Gradient And Vehicle Load

Temperature has important influence on bearing capacity and performance of the pavement structure, the temperature stress will cause temperature deformation and the temperature deformation will cause uneven settlement of pavement structure, or causes the slab void, accelerating damage of the pavement. Therefore, it has important significance to correctly simulate the distribution temperature field of cement concrete pavement and analyze response of the cement concrete pavement to stress under the action of temperature and axial load. By employing the finite element software Everfe2.25, the paper simulates the response of the cement concrete pavement under the action of the linear and nonlinear temperature gradient as well as axial load to the slab stress. For the analysis of the response of nonlinear temperature gradient at different degrees to the slab stress, the nonlinear temperature distribution index is introduced.the results of the research are as follows:(1) When the cement concrete pavement is only under the action of the linear temperature gradient load: Pavement structure is composed of only slab and the foundation,The parameters influence the temperature stress of the concrete pavement is almost same with the theoretical solution. Pavement structure is composed of slab, base and the foundation, setting base can effectively reduce the temperature stress of the cement concrete pavement, and the influence of interlayer contact on the temperature stress is much greater than the that of the base modulus and thickness; when the surface and base are completely smooth the temperature stresses is minimum, when fully bonded, the temperature stress is maximum.(2) Taking into account the nonlinear distribution of temperature on the cement concrete pavement. The results indicate that although the deformation caused by linear temperature gradient models was almost identical with that from nonlinear temperature gradient models, the linear temperature gradient models have overestimated bottom-up stresses and underestimated top-down stresses. when the nonlinear temperature gradient is negative, the influence of nonlinear temperature gradient on slab stress increases with increasing slab thickness and elastic modulus. Besides that, the effect of nonlinear temperature gradient was reduced when increasing the base reaction module. What's more, based on the regression analysis of a large database, the formula for maximum tensile stress of the slab top is obtained.(3) When the cement concrete pavement is under the action of the linear temperature gradient load and axial load.Pavement structure is composed of only slab and the foundation, Under the negative temperature gradient and axial load, the peak of the slab coupling stress is smaller than that under independent action of the temperature gradient; under the positive temperature gradient and axial load, the peak of the slab coupling stress is larger than that under independent action of the temperature gradient and axial but smaller than there stacked result. the axial load acting on the slab edge was the most unfavorable position. Pavement structure is composed of slab, base and the foundation, when the base and surface are fully smooth; the peak of the coupling stress is larger than that of the stacked result of the two stress peaks. Then the parameters influence of the slab coupling stress is also analyzed.