Dynamic properties of loose sand using numerical analysis-A case at Hong Thai Tay coal transportation road project (Vietnam)

Abstract

In this paper, a study was conducted to investigate the dynamic behaviors of loose sand collected from Hong Thai Tay coal transportation road project (Vietnam). Cyclic direct simple shear tests (CDSS) were performed on the soil using a finite element method program. The CDSS test was controlled under drained strain condition with the vertical effective consolidation stress of 100 kPa. In addition, the other dynamic control parameter, cyclic stress ratio, was subjected to vary in the range of 0.04-0.1. A total of 30 cyclic direct simple shear tests were performed with respect to the number of uniform cyclic cycle and cyclic stress ratio to determine the dynamic parameters of the sand plasticity model. Eventually, the dynamic properties of the investigated sand were ob-served through various dynamic aspects. As a result, the strain amplitude of the loose sand in this study slightly increased within the first fifteen-loading cycles. From the sixteenth cycle, huge increments were observed during the cyclic test. This result agreed well with that of excess pore water pressure ratio, that is, the development of excess pore water pressure reached about 1.0 after fifteen cycles of loading. Moreover, the obtained results of the shear modulus reduction ratio from this study were compared to those of sand from the literature reviews.