Geotechnical characteristics of Dhaka clay

Abstract

In this research change in undrained shear strength 5u due to swelling under ko and isotropic stress conditions is investigated for remoulded Dhaka clay, collect~dfrom BUET campus. The remoulded samples were prepared from slurry having a water content twice the liquid limit inorder to attain a uniform density. The ko samples were consolidated in a large oedometer and then subjected to undrained triaxial shear strength test. The isotropically consolidated samples were consolidated to a small ko stress condition prior . to isotropic consolidation and then subsequently subjected to undrained triaxial shear •. The results indicate that the relationship between the ratio 5}u6 va., where ava. is t.he vertical effective stress at' . I the end of swelling, and the overconsolidation ratio n is represented by a straight line in logarithmic plot, both for ko conso;idated and for isotrdpically consolidated samples. The uridrained shear strength of naturally occuring Dhaka clay is predicted using the log linear relation between 5,u/6 vo obtained e~perimentally from Dhaka clay. Some amount of agreement is observed between predicted and measured shear strength although unoertainties remain' due to soil variability and sampling factors. Further more coefficient of earth pressure ko is determined for both normally loaded and overconsolidated condi tions.