Elasto-plastic theory for soft clay behavior in overconsolidated states | |
| Author | Sharma Acharya, Shambhu Sagar |
| Call Number | AIT Thesis no. GE-98-29 |
| Subject(s) | Strains and stresses Soil consolidation test |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | An elasto-plastic stress strain model for describing the behavior of normally to overconsolidated clays is formulated based on the concepts of Critical State Soil Mechanics. For the fo1mulation of the model, an experimentally based relationship for undrained shear strain, a relationship for plastic strain increment ratio is proposed. A relationship for the variation of IL inside the SBS i.e. Aoc is also proposed. Using this relationship for the known undrained stress paths, the volumetric strain inside the SBS can be calculated. The total shear strain is then determined using the proposed flow rule together with the incremental relationship of Roscoe and Poorooshasb (1963). But for the case when the undrained stress paths are not known an empirical relationship between void ratio and stress ratio is proposed based on the experimental observations. Using this relationship together with the ideas underlying Critical State Soil Mechanics, an incremental relationship for total volumetric strain is developed and thus the total shear strain can be calculated using the proposed flow rule and the empirical relationship of undrained shear strain. The linear relationship of the stress ratio in e- 1n p plot is assumed to calculate the undrained mean normal stress as the void ratio corresponding to that stress ratio is known for the conventional drained path. The model complexity to characterize the soil behavior is controlled through the use of few input parameters, which can be determined from the Standard laboratory tests. A detailed assessment of the predictive capabilities of the proposed model is also presented in comparison to the Pender's model. The proposed model gives good estimation of the soil behavior especially for the isotropic pre shear consolidated samples over wide variety of loading conditions. |
| Year | 1999 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical Engineering (GE) |
| Chairperson(s) | Balasubramaniam, A. S.; |
| Examination Committee(s) | Der Guey, Lin;Seah, T. H.; |
| Scholarship Donor(s) | Government of Japan; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1999 |