The study of deformation properties of a sand soil - expanded polystyrene granules mixture under cyclic loading conditions

Abstract

The development of advanced materials for oil and oil products storage tank foundations under low temperatures and efficient technologies for their construction is an urgent task for oil and gas industry. It is proposed to use heat-insulating additives, for example, expanded polystyrene granules to reduce heat losses in foundation soils. The purpose of the research is to study the effect of artificial thermal insulation additives in sandy soils on the deformation properties of the resulting mixture. To achieve this goal, it is necessary to solve the following tasks: to prepare samples of the mixture "Sandy soil – expanded polystyrene granules", to carry out compression tests of the prepared samples and to process the results. Compression tests were carried out on samples of sandy soil – expanded polystyrene granules mixture with a 5% content of heat-insulating additives. Each test included five consecutive loading-unloading cycles. The maximum value of loading was 180 kPa. In the course of laboratory studies, data of a calculated value for a deformation modulus of investigated samples for the sandy soil – expanded polystyrene granules mixture were obtained. The calculated value of the mixture deformation modulus after the 4th loading cycle was 16.4 MPa, which was higher than minimum allowable (15 MPa) by 9%, and after the fifth cycle this value was 15% higher. The obtained results allow us to develop a tank foundation structure with improved heat-insulating properties and technology for its construction.