STRESS-STRAIN-DILATANCY RELATIONSHIPS OF NORMALLY CONSOLIDATED DHAKA CLAY

In this paper, stress-strain-dilatancy relationships of normally consolidated Dhaka clay is presented. Two constitutive models Cam-clay model (both original and modified) and sub loading tij model are used in this paper. To obtain the parameters, drained triaxial tests of saturated cylindrical specimens under compression is conducted. One dimensional consolidation test is also conducted to obtain other model parameters namely compression index and swelling index. Total four sets of the undisturbed specimen are prepared where each set contains two specimens. Consolidated drained triaxial compression tests are conducted on first three test sets and thereby stress-dilatancy relation in compression condition is evaluated. To understand the behavior in extension one-dimensional consolidation test and drained triaxial test are performed on the test set four to obtain the model parameters. It is observed from the stress-dilatancy relationship that, sub loading tij model can well describe the stress-dilatancy behavior of normally consolidated Dhaka clay than that of the Cam-clay model both in compression and extension conditions. In compression condition, sub loading tij model presents almost a unique stress-dilatancy relationship for all three sets of specimens. Also in extension condition, a unique relationship between stress and dilatancy is observed where Cam-clay model failed to describe it uniquely. Therefore, sub loading tij model can be used with better accuracy for the Dhaka clay.