Flexible Surfaces on Viscoelastic Subgrades

This paper is concerned with the analysis of stress and deformation of a subgrade strengthened by a flexible surface plate subjected to a load distribution. Rate effects, creep and stress relaxation in components of such foundations are included through the application of linear viscoelastic theory. It is shown that elastic analyses for such situations which have been actively developed in recent years can be directly extended to treat the analogous problem including viscoelastic effects. Particular examples are presented for constant loads suddenly applied and maintained. In contrast to elastic solutions, the rate influence causes variation of deflection, subgrade pressure and plate bending moments as the constant loads are maintained for extended periods. The significance of the problem and the discussion of particular solutions as well as the general development of the theory are presented.