Experimental Investigation on Crushing of Granular Material in One-Dimensional Test

A series of one-dimensional compression tests have been carried out on three kinds of granular materials in a dense state to investigate their mechanical and crushing behaviours. A new testing apparatus that can simultaneously measure the axial and lateral stresses acted on the cylindrical specimen was also developed. Experimental results show that the break-point stress Lon e - log p curve is the largest for glass beads ballotini. A rise in compression index with the increasing axial load is observed for all three granular materials. The lateral earth pressure co-efficient at rest K-o for the three granular materials slightly increases with the increasing axial load and attains a steady value between 0.25 and 0.3 at the initial loading stage. The value for K-o markedly increases as the axial load is removed during the unloading process. The axial strain of Masado is the largest at the same axial load level due to its mineral hardness. Experimental results demonstrate that the crushing degree of granular material is greatly influenced by the loading modes and conditions.