Keywords : Saturated sand
Engineering and Technology Journal,
2014, Volume 32, Issue 11, Pages 2608-2626
This paper focuses on the effect of machine vibration on the variation of excess pore water pressure and settlement of saturated sand. A special setup is designed and manufactures to simulate the vertical vibration of the machine. A total number of 36 model tests are conducted on sand using three relative densities (35, 60 and 85%) representing loose, medium and dense sand respectively. These tests were performed on saturated sand, and tested under dynamic load. Different load amplitudes (0.4, 0.6 and 0.8 kN) and different frequencies (0.16, 0.5, 1 and 2 Hz) were used.
The results show that, the settlement in saturated sand under vibrating load increases with increasing load amplitude while it decreases with increasing frequency and relative density, but the rate of settlement decreases as the load increment increases. The maximum increase in settlement ratio reaches about 36% when the load amplitude changes from 0.4 to 0.6 kN while it is only 21% when the load amplitude changes from 0.6 to 0.8 kN.
The excess pore water pressure increases with increasing the load amplitude, frequency and relative density. The rate of change in excess pore water pressure increases about 30% as the load amplitude increases from 0.4 kN to 0.6 kN while it increases only 21 % when the load amplitude increases from 0.6 kN to 0.8 kN under the same frequency and relative density.