Investigation of agricultural soil shear strength under the freezing and thawing process

Soil is composed of fine particles that the space between the particles filled by water or air. The suitable combination of soil, water and air is necessary for growing of crops. The freezing and thawing process is one of the natural factors that improve the soil structure by changing the soil physical and mechanical properties. In this study, for investigation of soil shear strength under the freezing and thawing process some experiments on soil samples were performed. For this purpose, the soil shear strength was investigated in -10 °C as a freezing temperature, with two humidity levels (10 and 15%) and three levels of density. The results indicated that the freezing and thawing process decrease the soil shear strength. In the investigated range of soil density, by increasing soil density, the effect of freezing and thawing on soil shear strength was increased.