A simple critical state approach to predicting the cyclic and monotonic response of sands with different fines contents using the equivalent intergranular void ratio

This paper focuses on developing a simple approach to describing the monotonic and cyclic behavior of sands with fines by employing the concept of equivalent intergranular void ratio, eg*, in the critical state soil mechanics framework. To establish and evaluate this approach, which facilitates the process of predicting the soils behavior and minimizes the experimental work required, a large number of datasets published in the literature for 10 different types of soils are processed and analyzed. The proposed approach makes it possible to predict the behavior and resistance of sands in a unique way for all the fines contents, stress levels and densities, without the need for performing tests at different fines contents. The issue of determining the b value, used as a physical constant in the definition of eg*, and the factors affecting it is studied. In this context, a recently established b-predicting equation is evaluated and its empirical parameters are calibrated with various datasets. Examining the influence of grading parameters on the b value resulted in a strong relationship between b and the particle size ratio. The results also show that the b value can be reliably estimated using the experimental data available at only two fines contents of 0 and 23 %.