Abstract:

Four different scaling methods are used to scale a coarse-grained soil into a grading with smaller particles. The methods are mixing method, scalping method, equal-weight replacement method and similar grading method. The biggest grain size of each soil after grading is 10mm, 20mm, 40mm and 60mm, respectively. A number of relative density tests are conducted. To further analyse the test results, more relative density for other three soils with arbitrary grading are performed. The maximum and minimum dry density tests are carried out using vibrating method and loose filling method. The relationship between maximum or minimum dry density and the soil grading parameters, maximum particle size is investigated under the same compactive effort. A normalizing method is presented to express the relationship between dry density and grading. The relationship of dry density versus Cu, Cc and maximum particle size is found. According to the relation, the maximum dry density of the real gradation can be determined.

Key words: coarse-grained soil, scaling method, maximum dry density；gradation