Comparison of Maximum Shear Modulus Interpreted from CPT and Laboratory Tests for Eastern Indian Offshore Clays

Abstract

Maximum shear modulus, Gmax (also called initial shear modulus), is an important parameter for offshore foundation design which is either interpreted from CPT using established correlations or derived from bender element or resonant column tests on high-quality retrieved samples in the laboratory. Since the reported correlations with CPT are area-specific, there was a need to develop such correlations for eastern Indian offshore also where big oil and gas field developments are being planned. Such correlations can help in optimizing the costly field and laboratory testing programs for future projects. The correlations also act as a check on the field and laboratory investigation results. With an objective to validate the reported correlations or develop new correlations, available CPT and laboratory test data on clays from shallow and deepwater areas of eastern Indian offshore were compiled and evaluated using correlations reported in the literature. This paper, after presenting the data, discusses the results of such evaluation and attempts to develop new correlations between maximum shear modulus derived from laboratory tests and CPT parameters.