Numerical and experimental modeling of geomechanical behavior of partially saturated soils

• Published in: International journal of geo-engineering 2021-12, Vol.12 (1), p.1-22, Article 25
• Main Authors: Sadeghabadi, Alireza, Noorzad, Ali, Zad, Amirali
• Format: Article
• Language: English
• Subjects: Anisotropy; Barcelona Basic Model; Civil Engineering; Earth and Environmental Science; Earth Sciences; Engineering; Exact solutions; Expansive soils; Experimental analysis; Finite difference method; Foundations; Geoengineering; Geomechanics; Geotechnical Engineering & Applied Earth Sciences; Hydraulics; Mathematical models; Numerical computations; Original Research; Partially saturated soils; Saturated soils; Shear strength; Simulation; Soil compaction; Soil strength; Soil suction; Stress paths; Tensile strength; Unsaturated soil; Unsaturated soils; Wetting
• ISSN: 2092-9196; 2198-2783
• DOI: 10.1186/s40703-021-00154-3

The Barcelona Basic Model (BBM) has been implemented in a finite difference-based computer program to simulate the behavior of unsaturated soils subjected to wetting. The BBM implementation was verified using analytical solutions, and the proposed model has been used to simulate the response of a compacted embankment under complete saturation and suction induced conditions. Numerical analyses indicate that considerable amount of total and differential settlements could develop at the top surface of the embankment. BBM is executed into FLAC 2D extending a defined module for modified Cam Clay (MCC) and has been set up an analytical solution for suction-dependent stress and strain. Evaluating the effect of anisotropy and nonlinear apparent tensile strength in unsaturated soils, a modification to BBM formulation has been proposed and optimized by developing numerical analyses to reduce the size of elastic region of loading collapse (LC) curve. Then, an experimental study in the literature is investigated by utilizing comparative curves from BBM and modified BBM indicating well agreement with natural circumstances. As a result of the work presented in this research, finite difference codes with BBM and modified BBM has the capability of simulating the real behavior and is operational being applied to problems associated with earthen structures in unsaturated or partially saturated of expansive soils as a three-phases medium.