被砾石与地层砂混合物充填的射孔孔道
gravelsand filled perforation tunnel
孔道摩阻值测定
measurement of friction resistance in prestressing ducts
measurement of friction resistance in prestressing
孔道摩阻系数
friction resistance coefficient
孔道摩阻损失
tube frictional resistance
孔道摩擦
Friction with the wall of duct
孔道密实程度
the degree of pore-compacting