Experimental investigation – influence of the shape of the gradation curve on the soil structure

摘要

Internal erosion has been a major problem associated with earth structures for years. Gap-gradedrnsoils are defined as soils in which one or some fractions do not exist. Soil structure can be generally estimatedrnwith the Sequential Fill Test (SFT). This test is based on bimodal soil structure theory, where the separationrnpoint can be measured for different particle size distributions. The separation point shows the dominant matrixrnin a soil structure. Here, a matrix analysis method is proposed for identification of dominant soil matrix. Thisrnmethod is validated using modified SFT on a widely gap-graded soil. The focus was on the variation of the gaprnlength. It was shown that the matrix can shift from fine matrix to dominant coarse matrix. For each PSD existsrna minimum length of gap which can be defined as transitional gap length.