Numerical investigation of strain rate effect for CRS consolidation of normally consolidated soil

Constant rate of strain (CRS) consolidation tests are commonly used to measure consolidation properties of fine-grained soils. A series of numerical simulations was conducted using the CCRS1 model to investigate the effect of applied strain rate on accuracy of data analysis methods given by ASTM D4186/D4186M-12e1. The simulations consider six normally consolidated soils, each with rate-independent constitutive relationships, constant coefficient of consolidation, and constant coefficient of compressibility or compression index. Results indicate that high values of applied strain rate can introduce significant error for calculated consolidation properties (compressibility, hydraulic conductivity, coefficient of consolidation) using both linear and nonlinear analysis methods. Results also indicate that the normalized strain rate b governs CRS consolidation behavior and that CRS tests generally should be conducted with b0.1. Finally, correction factors are proposed for calculated values of coefficient of consolidation from CRS tests on normally consolidated soils.