Analysis and Modeling of Prediction of Plane Strain Properties of Cohesionless Soils from Direct Shear Test

Abstract

Direct shear test is commonly used for research and geotechnical engineering design due to its simplicity and cost effectiveness. However, analysis of many geotechnical structures such as earth pressure and slope stability problems require measurement of shear strength properties of cohesionless soils. Therefore, it is usually relied on empirical relationships like correlation to predict soil properties from direct shear test. One of the key issues in both the execution and design stage is to ensure stability of buildings especially when unfavorable soil conditions are present. Hence, accurate information regarding geotechnical parameters are required for establishing the correlations.An investigation of the shear strength of cohesionless soil is carried out using direct shear apparatus according to relative density ranging from 15 to 95%. From the experimental study, angle of shearing resistance and angle of dilation is obtained. Correlations of angle of shearing resistance and angle of dilation interms of relative density is arrived from Principle of least squares, Trend line approach(MS-Excel) and Regression model. From these correlations, the best fit linear equation which is having higher strength and minimum error is obtained. This correlation is checked with ANOVA Single Factor for its reliability. From this computer data, the best fit for the linear correlation is Principle of least squares. This correlation will be helpful for the geotechnical engineer to predict the shear strength parameters of different cohesionless soils in the design process of embankments, retaining walls and slope stability problems.