Experimental Study On The Static Characters Of Coarse Grained Soil

At present, China is undergoing the hydraulic project construction, industrial construction, civil with a rapid development, the application of granular materials are increasingly being used, especially in the dam construction, coarse aggregates is the main large amount of embankment material, as the height of dam is increasing in China, only the nature of the coarse aggregate in depth research, could we guarantee the normal operation of dam and its safety. The coarse aggregate particle breakage occurs under high stress phenomenon, it may have a greater impact on its strength and deformation, its impact mechanism remains further study. The stress-strain model and Duncan-Chang constitutive model of soil is on the base of mechanical properties of clay, whether they are applicable different coarse aggregates, especially existence severity grain broken up phenomenon, remains to be further improved. According to these questions, this study and discussion focus on above issues.The influence of the initial dry density and fines content of coarse aggregate on the strength and deformation have studied, the results show that in the case of the relative density unchanged, inside rub cape increases with the increasing of density, to a certain extent, the inside rub cape decreases with the increasing of the percent fines.The effect of the geotechnical cloth on the test results have also studied, the impact mechanism of geotechnical cloth is analyzed by comparison experiments under the conditions of coarse grained soils with geotechnical cloth and without geotechnical cloth. The results show that the inside rub cape of the coarse grained soils with geotechnical cloth is larger than that without geotechnical cloth, The effect of the geotechnical cloth was decreasing with the increasing of the grain radius.Two three stalk experiments of coarse grained soils have been carried under the dry condition and saturation condition. The result show that the grain breakage ratio of saturation condition is larger than that of dry condition, at the same time, we also find that there is only one relationship under the isotropic consolidation between the grain breakage ratio and the peak internal friction angle.The test results of coarse aggregate verified Duncan-Chang constitutive model, further confirmed Duncan-Chang constitutive model could reflect their stress-strain characteristics, but could not reflect the volumetric strain characteristics, the modified Duncan-Chang constitutive model preliminarily confirmed in reflecting the volumetric strain response of coarse grained soil.