The Research Of Dynamic Characteristics Of Sand By Column Resonance

Dynamic shear modulus and damping ratio are the two key parameters in geotechnical engineering design and construction and play an important role in soil dynamic seismic analysis of geotechnical problems and equipment foundation design analysis. Dynamic behavior of soil influenced by many factors,there are still defects in previous research. This paper summarizes the results of research on the basis of the past, for the dynamic properties of soils in small strains, we use GDS resonant column system to test Japan Toyoura sand in different consolidation ratio of 15 sets of experimental conditions. We do a series of test for Japan Toyoura sand in small strain and research the effects of confining pressure and pore ratio in different consolidation ratio. Getting the relation beteen the normalized dynamic shear modulus and shear strain Gmax / G- ? under different consolidation ratio,discussed the effect about damping ratio in different consolidation ratio. Though the test of Japan Toyoura to revise the recommendations formula about anisotropic consolidation condition of maximum dynamic shear modulus,contracting the result of anisotropic consolidation condition of 1969 Hardin and China Earthquake Administration in 2005.The results in this paper show that the formula in the growth rate between the two formulas, but both the calculation formula of China Earthquake Administration and this paper show the degree of anisotropic consolidation on soil maximum dynamic shear modulus higher than Hardin formula.Using the Wet sand and dry sand to make the different fabric by Japan Toyoura sand, testing six sets in 35 kPa confining pressure and confining pressure 150 kPa about dynamic shear modulus time effect, research under different fabric loose sand, medium sand, dense sand at small strain shear modulus under the time effect.Using bender elements to explore dry sand under anisotropic consolidation condition of maximum dynamic shear modulus changes, and contrast with the resonant column anisotropic consolidation tests.