为充分利用粘性土的抗剪强度,在计算土压力时,应用换算(计算、综合)内摩擦角φ＇进行计算。这由于库伦和兰金公式皆为砂性土的土压力公式。而考虑粘性土的土压力公式,除个别特例外,都过于复杂。在一般工务工程的应用上,不如采用换算内摩擦角的方法。 In order to make full use of the shear strength of cohesive soil, calculation of earth pressure is calculated using the conversion (calculation, synthesis) internal friction angle φ ’. This is due to the formula of Coulomb and Rankine are earth pressure formula of sandy soil. Considering the earth pressure formula of clay, it is too complicated except for a few special cases. In general public works engineering applications, it is better to use the method of conversion of internal friction angle.