Measurement of the Pore Pressure Parameter C Less Than Unity in Saturated Sands
Two saturated sands, Monterey No. 0/30 and Enewetak coral, tested undrained under one-dimensional strain loading, were found to have values of the pore pressure parameter C, less than unity. The C parameter for Monterey No. 0/30 sand, determined to be unity at an effective consolidation stress of 86 kPa, decreased with increasing effective consolidation stress and increasing relative density. A similar behavior was observed for the Enewetak coral sand. These trends are similar to those reported by other researchers for the pore pressure parameter B. The decrease in C parameter values for saturated specimens appears to be a direct result of increasing skeleton stiffness due to increases in effective stress and density. A theoretical analysis of skeleton stiffness based on porosity and pore pressure response predicts similar trends.