Effect of Openings on Stresses in Rigid Pavements

A typical airport pavement section 12 in. (0.3 m) thick resting on a subgrade material have a modulus of elasticity, E°SsTD, equal to 8,400 psi (58 MN/mFRUS2TUTF) and treated as an elastic continuum is considered in this study. To limit the size of the slab, four cuts together with the corresponding boundary conditions were inserted at carefully chosen locations. Influence lines for the stresses f°SxTD and f°SyTD as well as stress distributions due to wheel loads were computed for critical locations of the load. These stresses were then compared with those obtained for an identical pavement section without opening under the same loading conditions. This comparison showed that a large increase in the value of maximum stress would result from the presence of the opening. A method is suggested to calculate the tensile forces around the opening. A simple formula for calculating the area of steel reinforcement required for a typical case has been derived accordingly effect of changing the length of the opening on the values of the stresses along its transverse edge was determined for the case of a point load.