Research Reports |
Title: | Development of Models for the Prediction of Shear Strength of Swelling Clays |
Authors: | Dinesh R. Katti, Kalpana S. Katti, Keshab B. Thapa, and H. M. Nasrullah Faisal |
University: | North Dakota State University |
Publication Date: | Dec 2019 (Interim Report) |
Report #: | MPC-19-406A |
Project #: | MPC-548, MPC-506 |
TRID #: | 01743866 |
Keywords: | clay, clay soils, compressibility, compression tests, mechanical properties, molecular structure, montmorillonite, shear strength, swelling soils |
Type: | Research Report – MPC Publications |
Accurate prediction of the shear strength of swelling clays is critical for the design of infrastructure. Damage caused to U.S. infrastructure by swelling clays is estimated to be about $13 billion per year. Overestimation of strength can lead to failures, and underestimation can lead to an increase in project cost. Due to the small size of the clay particles and the nature of clay minerals, molecular interactions between the clay and fluids strongly influence engineering properties. In this research, we investigate the role of molecular interactions on the shear strength of swelling clay. This understanding can lead to the development of robust capabilities for accurate prediction of the shear strength of swelling clays. In this interim report, we present the results from our ongoing work that include the findings of the role of molecular interactions on the swelling, compressibility and shear response of montmorillonite clay interlayer using molecular dynamics. Results from unconfined compression tests and nanoindentation tests on saturated samples at 0% swelling are presented, and experiments with increasing swelling are ongoing. The development of molecular-scale clay tactoid, clay aggregate, and coarse-grained models to evaluate interparticle shear responses are in progress.
Katti, Dinesh R., Kalpana S. Katti, Keshab B. Thapa, and H. M. Nasrullah Faisal. Development of Models for the Prediction of Shear Strength of Swelling Clays, MPC-19-406A. North Dakota State University - Upper Great Plains Transportation Institute, Fargo: Mountain-Plains Consortium, 2019.