In attempt to estimate theoretically the shear-normal pressure ratio on slab subgrade interface, and to develop moment expressions for the slab for use in the case in which shear contact does exist at the interface, a statistical analysis was made of a slab half-space system subjected to normal axisymmetric loading, assuming full continuity of stresses and displacements in the interface plane. Parametric studies of moment in slab were also made. The coordinate system used for the problem is illustrated and details are given of the derivation of equations, and the evaluation of infinite integrals. To test the accuracy of computation, several integral values were checked against those obtained by numerical integration. To study the magnitude of the shear stress relative to normal pressure at zeta=0, their ratio is plotted for two different sets of parameters. In general, the effect of shear is observed to be greater for stiffer subgrades than for the weak. The variation of plate moment at the center of a circular loaded area is discussed and the sensitivity of the plate moment at the center of the circular loaded area to slab and subgrade Poisson's ratio is shown. Sliding tests on pavements have yielded frictional coefficient values (mu) as high as 1.5. A value of the ratio of shear stress relative to normal pressure less than mu, suggests the possibility that the slab subgrade may act in welded contact, particularly if warping does not cause a pressure loss. This condition, together with certain combinations of v and v sub 1 will result in slab movement values that are more critical than those obtained with shearless contact between the slab and subgrade.

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  • Accession Number: 00083664
  • Record Type: Publication
  • Report/Paper Numbers: ASCE #11093 Tech. Note
  • Files: TRIS
  • Created Date: Apr 22 1975 12:00AM