The purpose of the study is to reveal the effect of the stress-strain state of the three-layer soil base of the slab foundation with a rigid underlying layer, which is heterogeneous along the depth of the ground. The main results of the study are obtaining relative deformations in the soil massif and the settlement of ground values of each layer. The results of experimental studies are obtained in the form of a deformation pattern of a layered base, distribution graphs of compressive stresses in the soil in depth and in a horizontal plane. The significance of the results achieved for the construction area is to establish the mutual influence of various soils on the stress-strain state of the laminate basement of the slab foundation. The presence of a dense top layer in a laminate base significantly increases its distribution ability. The stress distribution is proportional to the load-carrying capacity of the individual base layers. On the boundary between the layers, a jump in the compressive stresses may occur, which indicates the presence of shear deformations in the contact layer.