BBM-Type Constitutive Model for Coupled Chemomechanical Behavior of Saturated Soils

Abstract

Many engineering problems, such as soil stabilization, nuclear waste storage, and oil and gas extraction, require understanding and modeling of the coupled chemomechanical behavior of soils. Based on the framework of the Barcelona basic model (BBM), a constitutive model (BBM-C) for addressing chemomechanical coupling behavior of saturated soil is proposed. By replacing matric suction with osmotic suction, the analogous yield function, hardening law, and flow rule are introduced for the BBM-C. This study also presents a parameter calibration method for the proposed constitutive model. To validate the BBM-C, three oedometer tests, in which the specimen was subjected to mechanical loading with constant osmotic suction, were used to calibrate the model parameters. Two other oedometer tests, including (1) mechanical loading at constant osmotic suction and (2) alternative chemical and mechanical loading, were used as blind tests to verify the proposed BBM-C with the calibrated model parameters. A comparison between experimental data and predicted results demonstrated that the BBM-C was able to capture the main features of the chemomechanical coupling behavior of saturated soil.