INCREASING THE STABILITY OF THE SAND CUSHION BY PRESTRESSING THE REINFORCING LAYERS OF GEOSYNTHETICS

Abstract

The use of prestressing of geosynthetics allows accelerate their inclusion in work, reduce deformations and gaining bearing capacity of artificial foundation. The article presents results of research of two methods of construction reinforced sand cushions. In the first case, the effect of prestressing is achieved due to a certain order of layer-by-layer soil compaction of the cushion, in the second - by laying of the swellable material between the contours of the foundations. The experiments were carried out in a laboratory tank with a pneumatic loading device. There are three stamps united by a common frame on the surface of the cushion. To assess the stress-strain state of the soil foundation, the non-contact digital tracer imaging method was used. The experimental results are presented in the graphs form of the dependence of the stamp settlement on pressure and vector fields of particle movements. Modeling has confirmed the high efficiency of prestressing. The ultimate pressure on the soil foundation with two-layer horizontal reinforcement and prestressing of the reinforcing layers in the first method was 195 kPa, in the second method - 165 kPa, whereas in the absence of prestressing this value was 110 kPa. Foundation deformations also decreased significantly.