The Concrete Substrate Static And Dynamic Characteristics Test

The research of this thesis is supported by China National Natural Science Foundation. The static and dynamic behaviour of slabs on foundation and doweled slabs of concrete pavement, identification and comparison of static and dynamic parameters are studied emphatically in this paper. The main characteristic contents are as follows:(1) Strains, displacements, reaction of soil, natural frequencies and main mode shapes et al are examined in the static and dynamic experiments of slabs on foundation and doweled slabs of concrete pavement. Some significant conclusions are drawn.(2) Stresses calculation of slabs and beams on foundation is performed. Hankel integratiag transform is used to calculate and analyze infinite slabs on single parameter fourdation, two parameters foundation or subspace foundation. Energy variational pr nciple is used initially to discuss beams on two parameters foundation consideringAe influence of foundation around systematically, which involves the infinite, semi-infinite and finite long beams. Superposition method is introduced to calculate rectangular slabs on single parameter foundation and two parameters foundation under static load.(3) Analysis on joints of concrete pavement is made. Bending and shearing beam model should be used to simulate the dowel bar. The traditional device is updated in order to measure the rotation and displacement between both slabs. The shearing force and moment are equally important when affecting the deformation of dowel bar. Both should be considered in joints analysis of concrete pavement.(4) Dynamic calculations of slabs and beams on foundation are performed. The occurring conditions of rigid mode are discussed in detail. The concept of normal and generalized rigid mode is introduced. Affecting factors and characteristics of mode of free slab and beam are studied. Rayleigh-Ritz method is used to calculate the complete mode, giving mode shape approximate function. The transfer of shearing and moment must be considered in dynamic analysis because the model of dowel bar affects the modal frequency and modal shape directly.(5 ) Finite element analysis of slabs on two parameters foundation is presented. Based on the Mindlin-Reissner plate theory, a generalized conforming element for thick-thin slab onfoundation is formulated. The numerical results of FEM are in good agreement with the experimental results. For comparison, the results for Winkler and Subspace foundation are also given.( 6 ) Deflection reverse analysis and genetic algorithms are used to identify the foundation parameter, in order to realize original location test of foundation parameters. A number of calculation examples, including past experiments, our experiments, thick slabs experiments, thin slab experiments, single slab experiments and doweled slabs experiments, are given. By comparing test values with calculating values, some significative conclusions are drawn. The superiority of generalized conforming element for thick-thin slab on foundation is pointed out. The average ranges of foundation parameters are given according to these experiments.