Prediction of Compressibility Behavior of Clayey Soils of Different Plasticity for Containment Applications at Large Consolidation Pressures

Increase in the application of clayey soils in geoenvironmental engineering practice escalated the interest in understanding the compressibility behavior at higher consolidation pressures. Laboratory evaluation of the compressibility data in the higher consolidation pressure range is laborious, time consuming, and expensive. Therefore, theoretical predictions are required to determine the compressibility behavior at high consolidation pressures. Such models for predicting the compressibility curves at high consolidation pressures are limited and applicable either for only low quality clayey soils or very high plasticity bentonites. A general theoretical model, $e_i/e_{P_N}={(P_N/P_i)}^a$ (where, $e_i$ is the void ratio at any given consolidation pressure, $P_i$; $e_{P_N}$ is the void ratio at normalization pressure $P_N$; and $a$ is the intrinsic parameter), for the prediction of compressibility behavior over a wide range of consolidation pressures for clayey soils of different plasticity was proposed in this study. The proposed model was validated over 114 compressibility datasets from 88 clayey soils and bentonites with different inundation fluids and initial states that were obtained from the literature and from the present study. The intrinsic parameter was estimated from the measured void ratio data at low consolidation pressures. The estimated parameter was used to obtain the compressibility data to a very high consolidation pressures ranging between 0.4 and 42 MPa for different clayey soils. The intrinsic parameter in the proposed model varied from 0.714 for lithium bentonite to 0.1 for red soil and was proportional to the plasticity of the clayey soil. The general predictive equation is applicable to all the clayey soils with different plasticity and is suitable for estimating the compressibility data over a wide range of consolidation pressures adequately.