Estimation of Undrained Shear Strength of Overconsolidated Clay Using a Maximum Excess Pore Pressure Method Based on Piezocone Penetration Test (CPTU)

Abstract

Abstract Many methods can be used to evaluate the undrained shear strength (su) in unconsolidated or normally consolidated clay. However, among the many methods, few methods can be used to evaluate the su value in overconsolidated clay. In this paper, based on the piezocone penetration test (CPTU), the maximum excess pore pressure method (Δumax) was adopted to estimate the su in overconsolidated clay. In addition, three different test sites (in China) with overconsolidated clays were selected to verify the feasibility of this method. The test results show that the maximum pore pressure cone factor (NΔumax) significantly affected the evaluation of su. Moreover, the NΔumax values (8.10, 8.70, and 8.44) for 3 test sites in Yancheng, Nanjing, and Changzhou were obtained and can provide a valuable reference for evaluating su for in situ tests with overconsolidated clay.