Estimation of residual undrained shear strength from gravity corer penetration data

Residual undrained shear strength, s(u_res), is an important parameter for analyzing the response of structures buried within potentially unstable soil mass. A framework for estimating s(u_res) of fine grained sediments from gravity corer penetration has been developed considering viscous drag during free fall of the corer through sea-water and cohesive energy loss during sediment penetration. The procedure was used to estimate s(u_res) using data from a submarine geotechnical investigation in western Canada. Comparison of the results with alternative estimates of s(u_res) from miniature torvane tests on the gravity core samples and CPTs performed nearby reveals a reasonable agreement.