Research into compaction characteristics of large-size coarse-grained soil and application.

The filling characteristic of rockfill is a non-ignorable engineering problem for high dams, and a reasonable control of compaction quality is the key to promoting the development of high dams. In this article, numerical and field tests were implemented to study the main problems affecting the compaction characteristics of large-size coarse-grained soil, namely determinations of the reasonable H₀/d_max (the ratio of the compaction layer thickness to the maximum particle size) and the main influencing factors of minimum porosity. The macroscopic manifestations of the compaction characteristics were analyzed from the perspectives of energy, force chain, and particle breakage. The interaction between particles was explained by the 'filling effect' of fine particles, the 'wedging effect', and the 'wall effect' of coarse particles. It was found that the minimum porosity was not an inherent characteristic of rockfill, since the porosity and the corresponding degree of breakage were influenced by the compaction conditions. The value of H₀/d_max meeting engineering practice was proposed, which can create favorable compaction conditions for obtaining the minimum porosity. Meantime, some suggestions were provided for obtaining the minimum porosity of large-size coarse-grained soil. The research results have an application reference value for the filling design and evaluation of high dams. [ABSTRACT FROM AUTHOR]