Research On Structure Of Asphalt Overlay On Concrete Pavement In Moist And Hot Areas Based On Non-uniform Deformation Of Subgrade

In cement concrete pavement paved with asphalt overlayreformation, usually non-uniform deformation and bearing capacity ofsubgrade are considered insufficiently. Because cement concrete isbrittle material, and the ability to adapt the subgrade deformation is poor,in the asphalt overlay structure design did not consider the influence ofadditional stress on the pavement structure that produced under thenon-uniform deformation of subgrade. That will directly influence thefunction of surface, causing the destruction of the pavement. Moist andhot areas has characteristics such as high temperature and humidity andwet raining, new and rebuilt road were influenced by water, softfoundation. This paper through analyzing the roadbed non-uniformdeformation regularity caused by moisture influence, analysis thenon-uniform deformation of subgrade by numerical simulation, and alsoanalysis additional stress of pavement structure caused by non-uniformdeformation, and proposes the deformation adaptability of the cementconcrete structure and asphalt overlay. Firstly, the paper investigate and analyze the diseases of cementconcrete pavement in the moist and hot areas, provide the basis forasphalt overlay structure design. And related physical and mechanicaltest of high liquid limit clay was conducted, analysis showed that theproperties of high liquid limit clay has close relations with the waterstability. Through analyzing the Meteorological observation data,summarizes the climate characteristics and the types and features of thegroundwater in this areas. According to related research results,considering the influence factors that affect the non-uniformdeformation, such as accumulated water in subgrade side, side slopeseepage, change of ground water and so on. On the basis of using theSettlement theory and biot consolidation theory, comprehensiveconsideration of seepage water and soil deformation, An unevensettlement model was developed with the constitutive relation model inthe ABAQUS finite element software, summarizes the non-uniformdeformation rules of the road structure layers. Applied the non-uniformdeformation function to the subgrade end face by writing the subroutine of displacement load, numerical simulation the additional stress of thecement concrete pavement caused by non-uniform deformation, and theindex of subgrade non-uniform deformation is proposed. And analysethe mechanical response of overlay structure, put forward the typicalstructures of asphalt overlay in the moist and hot areas.