砾石土是土石坝常用的一种土料,可以作防渗体、均质坝坝体材料及坝壳半透水料。一般将土料中大于5毫米的颗粒称为粗粒(或粗料),小于5毫米的颗粒称为细粒(或细料)。砾石土是一种粗、细粒的混合土,而且细粒中含有一定数量的粉粒和粘粒,小于0.5毫米的颗粒 Gravel soil is an earth-rock dam commonly used as a soil material, can be used as anti-seepage body, homogeneous dam body material and semi-permeable dam material. Particles larger than 5 mm in soil are generally referred to as coarse (or coarse), and particles less than 5 mm are referred to as fine (or fine). Gravel soil is a coarse, fine-grained mixture of soil, and the fine particles contain a certain amount of powder and clay, particles smaller than 0.5 mm