|dc.description.abstract||The research focuses on a difference between Federal Highway Administration (FHWA) guidelines and Texas Department of Transportation (TxDOT) design practices for soil nail walls in high plasticity (i.e., plasticity index (PI) ≥ 15) clays. It will be going to validate TxDOT’s design approach, and then extending the topic to study time dependent behavior of soils, specifically the creep failure and the prediction of long-term deformation, followed by proposing some methods to reduce deformation caused by creep in practice.
A power law model is proposed to describe time dependent behavior of soils. The proposed model is fully demonstrated through enormous laboratory tests on three different soils, data from literature, four kinds of field tests and one field practice.
All objectives are fulfilled in this dissertation. The outcome of this research will give a support to TxDOT’s design practice then clarify (or even remove) the creep behavior restrictions in high PI clays in later revision of GEC#7. It will also increase the understanding of time dependent behavior of soils and its application in areas and circumstances where it was previously ignored. Besides, it will be useful to researchers and engineers for being able to reasonably predict long-term deformation in practice with the power law model. It also suggests three methods to reduce creep deformation in practice.||en