Modified Multi-stage Stress Relaxation Test Apparatus in Clayey Soils

A multi-stage stress testing device was developed for the relaxation of stress within the soil when a stable displacement is applied to the soil model. In the multi-stage relaxation of stress test (MRT), the pore water pressure, lateral stress and displacement are measured in addition to the vertical stress. In order to verify the results of the MRT test, laboratory tests were carried out on organic soil brought from the city of Amara in Maysan province near the Halfaia oilfield. A coefficient called relaxation factor, which can be found from the relationship curve at each stress stage, has been proposed. A multi-stage relaxation test is a parallel examination of compression or adhesion examination, characterized by a displacement load. The relaxation test has been proposed to study changes in stress after penetrating the piles which affect the computation of bearing capacity.