COMPARISON OF ATTERBERG LIMITS AND SHEAR STRENGTH VALUES AS DETERMINED FROM FALL CONE AND CONVENTIONAL METHODS

Abstract

Index properties play an important role in classifying soil regarding their engineering properties. To find these properties tests were initially given by Atterberg, and introduced by Terzaghi in soil mechanics. For every geotechnical site investigation, these tests form the background and have universal acceptance. This study was carried out to make comparison of Atterberg limits and Shear Strength values as determined from Fall Cone and conventional methods. For this purpose sixteen different samples from different areas in vicinity of Islamabad were obtained. Atterberg limits were determined by using conventional methods, i.e., Casagrande Method, Thread rolling method and Unconfined Compression test was used to determine Undrained Shear strength. These results were compared with those obtained with Fall Cone Method. Regression analysis was then performed and co-relations were determined for the values obtained by using these two methods. In the end established co relations were critically compared with the already established co-relations. The results of the study shows that Liquid Limit determined from Fall Cone is always greater than the Liquid Limit obtained from Casagrande Method. This is in accordance with the results of previous studies. The Undrained Shear strength obtained from Fall Cone apparatus are very high as compared with those obtained from results of Unconfined Compression test. The comparison of co relations established in this study with the co relations established in previous studies and also with the values obtained experimentally shows that the results of all co relations established are satisfactory.