Analytical Study On The Behavior Of Interaction Between Transversal Isotropic Elastic Foundation And The Pavement

The pavement system with the complicated structure is always considered as a large surface layer bearing on the infinitely deep foundation. Due to complexity and variety of materials and stochastic uncertainty of load boundary condition, many mathematic and mechanic problems will occur in obtaining stress and displacement solutions of the pavement system. By far, two hypotheses on foundation model has been widely adopted: one is Winkler foundation model (K foundation model) that foundation response modulus K is used to characterize foundation rigid; the other is elastic half-space foundation model (E foundation model) that elastic modulus E0 and Poisson ratio μ0 are used to characterize foundation rigid. In the present paper, E foundation model is adopted to simulate half-space elastic foundation body. In recent years, theories of elastic foundation and layers elastic body system have been widely applied and perfectly developed, but the theories often consider the medium as continuous, elastic, homogeneous, isotropy and submitting to small deformation hypothesis, and the anisotropy of the material has not been introduced.In the paper, consolidation effects on stress and displacement distributions aren't taken into consideration due to supposing that foundation soil consolidation has completed after surcharging preloading. Based on the inherent anisotropy and induced anisotropy of foundation soil body, transversely isotropic elastic constitutive relations are adopted to simulate half-space clastic foundation body. The relations between displacement and displacement function are proposed by extending T,ove displacement function to transversely isotropic elastic half-space. The general stress and displacement solutions of non-axisymmetric problems are obtained by Hankel transform, then the theoretical solutions of stress and displacement in transversely isotropic elastic half-space under arbitrary loading are put forward by introducing boundary conditions. The homogeneous elastic half-space solutions evolved from the theoretical solutions in the paper are in accord with classical ones. Solutions under horizontal and vertical loading can be obtained respectively by specializing arbitrary loading; by analogy, solutions under other loading can be also obtained.In the paper, the half-pace model with the surface layer bearing infinite foundation is adopted to simulate pavement system. The following assumptions are introduced: foundation soil is elastic; displacement of the interface between surface layer and foundation is completely continuous; no shear stress occurs on the interface between the surface layer and the foundation, namely no friction force. According to actual performance of rigid and flexible surface layer, visco-elastic model and elastic plates model are adopted to respectively simulate flexible and rigid surface, and the foundation is considered as transversal isotropic elastic body. Stress and displacement distributions of the foundation and the surface layer under static loading are analyzed by considering their interaction, and some valuable conclusions are obtained.