Investigation of stress reduction in sandy soils during saturation

If dry cohesionless soil material is saturated، stress reduction will occur in the soil mass، followed by sudden deformation،which is called collapse settlement. In this research، effect of saturation on the shear strength parameters of sandy soils and effective factors on collapse behavior of this material has been investigated by triaxialshear device. First of all، preliminary tests were performed in order to prepare physical properties of sandy soils including: grain-size analysis، specific gravity، maximum and minimum densities. After providing soil samples with specific relative densities، dry and saturated triaxialtests were carried out in different confine pressures to evaluate shear strength parameters of these materials. In order to investigate the stress reduction of material due to saturation، triaxial tests were done initially on dry samplesand shearing continued until a proposed stress level; keeping constant axial strain، samples were saturated until a period of time and shearing was continued again to reach failure in the wet state. In this way، effect of diverse factors such as confining pressure، shear stress level، relative density، initial moisture content and size of particles on the stress reduction of sandy material were investigated. Abstract: If dry cohesionless soil material is saturated، stress reduction will occur in the soil mass، followed by sudden deformation،which is called collapse settlement. In this research، effect of saturation on the shear strength parameters of sandy soils and effective factors on collapse behavior of this material has been investigated by triaxialshear device. First of all، preliminary tests were performed in order to prepare physical properties of sandy soils including: grain-size analysis، specific gravity، maximum and minimum densities. After providing soil samples with specific relative densities، dry and saturated triaxialtests were carried out in different confine pressures to evaluate shear strength parameters of these materials. In order to investigate the stress reduction of material due to saturation، triaxial tests were done initially on dry samplesand shearing continued until a proposed stress level; keeping constant axial strain، samples were saturated until a period of time and shearing was continued again to reach failure in the wet state. In this way، effect of diverse factors such as confining pressure، shear stress level، relative density، initial moisture content and size of particles on the stress reduction of sandy material were investigated. time and shearing was continued again to reach failure in the wet state. In this way، effect of diverse factors such as confining pressure، shear stress level، relative density، initial moisture content and size of particles on the stress reduction of sandy material were investigated. Abstract: If dry cohesionless soil material is saturated، stress reduction will occur in the soil mass، followed by sudden deformation،which is called collapse settlement. In this research، effect of saturation on the shear strength parameters of sandy soils and effective factors on collapse behavior of this material has been investigated by triaxialshear device. First of all، preliminary tests were performed in order to prepare physical properties of sandy soils including: grain-size.