Compression and recompression indices of a high plasticity clay consolidated under isotropic stresses

Abstract

The oedometer test is used to find out compression behavior of clays. This method takes a long time to measure compression of clays, leading to a problem of heavy workload in the laboratory. In settlement calculation of clayey, soil layers, compression (C-c) and recompression (C-r) indices obtained from the oedometer test are needed. However, duration of the oedometer test extends for calculation of the C-r index. It has been thought that working out the relationship between C-c and C-r indices and general characteristics of clays could be a first step to solve this problem. A number of parameters have an effect on the compression of clays. One of these parameters is the overconsolidation ratio (OCR). In this paper, the effect of OCR and initial void.ratio (e(0)) on C-c and C-r. indices of high plasticity overconsolidated clayey samples, which were remolded and prepared in the laboratory under different isotropic stresses, was studied. Thus, the oedometer tests were performed on these samples and consequently C-c and C-r indices were calculated. As a result, C-c and C-r. indices were somehow slightly affected by more than one parameter such as e(0) and OCR. At this stage, even though some other related studies are still in progress with respect to C-c and C-r indices, preliminary results of this study could provide some valuable contributions for both academia and practitioners.