Factor Affecting Shear Strength of Cohesionless Soil- Shear strength of cohesionless soils is only developed with the presence of effective stress. Shear strength increases with increasing effective stress. The increase of shear strength of cohesionless soil depends upon the internal friction angles of the soil. The type of soil most susceptible to liquefaction is one in which the resistance to deformation is mobilized by friction between particles. If other factors such as grain shape, uniformity coefficient, and relative density are equal, the frictional resistance of cohesion less soil decreases as the grain size of soils becomes smaller.