1‐D Strain in Normally Consolidated Cohesive Soils

A stress‐strain model for one‐dimensional strain in normally consolidated cohesive soils is compared to test results covering the stress range 0–950 atm. The model is called the “l/e vs. ${\sigma }_{\nu }^{\prime p}$ model” because the implied relationship between void ratio e and vertical effective stress ${\sigma }_{\nu }^{\prime }$ is linear in the normally consolidated range. The slope of the linear relationship is nearly independent of soil disturbance and its variation is relatively small for a wide variety of soils with different compressibilities. Because of this the effects of aging and soil disturbance are isolated to a single model parameter, providing a quantitative measure of these effects. The liquid limit is easily related to the model because the ${\sigma }_{\nu }^{\prime }=0$ state is included. These features provide for better interpretation of test results. An undisturbed sample can be tested as usual and then remolded to a water content slightly above the liquid limit. The liquid limit should be measured as water is added and the soil remolded. The final remolded sample should then be subjected to a 1‐D strain test. The results for both undisturbed and remolded samples define the model slope and the liquid limit and remolded test results are beneficial in choosing the best value of p. By following this procedure, all three tests are conducted on identical material.