Built to withstand the attack of small armies such as swords and spears, these walls were made mostly by stamping earth and gravel between board frames.
为了抵御小型兵器的袭击，例如剑、矛，城墙大多由版筑(在夹板中填入泥土和碎石)而成。
2
According to the principium and test method of RayleighWave, contrast carrying-board in locale(natural gravel) , found the regress equation between two modulus of subgraded and draw a conclusion.