粗粒土的颗粒破碎与临界状态

he grain crushing of coarse granular soils with high stress level has significant influence on its strength and deformation mechanisms. The soil mechanics theory based on critical state concept can describe the stress-strain relationship of reconstituted soil materials successfully, but currently for coarse granular soils, few studies are conducted on influence of grain crushing on critical states and mathematical description of critical state line. Based on lots of available test results, we investigated the critical states of coarse granular soils taking into account grain crushing and proposed a new formulation describing critical state line. Breakage index is first put forward to quantify the degree of breakage of soils and influence of grain crushing on critical states is then analyzed from which the mathematical equation of critical state line are deduced taking into account grain crushing. Finally the evolving rules of critical state lines with varying breakage index in coordinate plane of are explored in detail and compared with the results of triaxial compression tests, which indicts that the formulation of critical state line proposed here can describe quantitatively the critical state lines for coarse granular soils when grain crushing taking place.