Gravelly soils are made up of gravel

cobble

sand and cohesive soils and have been widely used in engineering such as earth-rock dams impervious fillings and stub cutoff walls. Their strength and mechanical property are affected by the content and bite extent and adhesive state of coarse grains and fine particles. The gravelly soil slope shape

soil mechanical property and slope stability under rainfall conditions

are researched through artificial rainfall field experiment

model experiment

indoor test and theoretical analysis. It is found that the gravelly soil slope likely exists criticality in the course of rainfalls and mechanics of thixotropic liquefaction. Result shows that the gravelly soil slope shape and sediment charge of the runoff has the character of phase

each representative phase moisture content is confine in some extent. Gravelly soil strength and slope stability has the character of criticality along with the moisture content; the critical point exists at the moisture content of 11 %.