Abstract: There are different opinions about thickness of sand mats for consolidation method.Based on the characteristics of distribution of settlement in the cross section of embankment and large-area loading zone,equations of hydraulic head in sand mats and equations of requirements of thickness of sand mats with different cross sections were derived according to the principle that the permeability of sand mats was equal to the velocity of draining of ground.According to the equations,the requirements of thickness of sand mats for consolidation method was related with the width of embankment or the distance of blind drainage,the velocity of primary consolidation settlement,the coefficient of permeability of sand mats,the maximum hydraulic head in sand mats,et al.Curves of hydraulic head in sand mats with different shapes of cross section or different parameters were different.The hydraulic head in sand mats with semi-concave-mirror cross section was lower than that in sand mats with other shapes of cross section when the volume and seepage velocity of sand mats were identical respectively.The proposed method and equations were proved by practical cases.