ABSTRACT
Subsurface investigations using Dilatometer Marchetti Test (DMT) were conducted in Kolkata at three locations predominantly consisting of silts. The over consolidation ratio (OCR) derived from the horizontal stress index (KD) as per Marchetti (1980) showed unrealistically high values (OCR > 2) compared to laboratory results. To address this discrepancy, DMTA dissipation tests were performed and the OCRs before and after dissipation are evaluated. The OCR values obtained from the dissipation tests align more closely with the earlier laboratory findings. Based on the results, a correction factor incorporating the OCR estimated directly from the DMT and the results obtained post-dissipation was recommended. Additionally, in-situ DMTA dissipation versus log-time curves were analyzed to estimate the horizontal coefficient of consolidation (Ch) for the typical Kolkata silty soil deposits. It is also intended to build on previous research and provide a reference dataset and case study for futuristic work in developing seismic resistant structures.
