Abstract: Analysis of active earth pressure under seismic condition is one of important contents in the anti-seismic design of retaining walls. In order to expand the applicability of classic Rankine earth pressure theory, diamond unit body is investigated according to the mechanical characteristics of inclined back?ll. On basis of Rankine's conjugate stress concept, the formulation of seismic active earth pressure considering cohesive soil and back?ll slope is proposed based on Rankine classic earth pressure theory and Mohr-Coulomb yield criterion. The results show that the formulas of classic Rankine active earth pressure and Rankine active earth pressure of cohesive soil considering back?ll slope are special cases of the proposed formulation. The proposed formulation yields comparable results to several existing calculation formulations for cohesive soil. The maximum error caused by different calculation methods does not exceed 10%. In addition, the vertical seismic coefficient and values of cohesion and soil internal friction angles have also been explored.

Key words: active earth pressure, pseudo-static method, Rankine earth pressure theory, Mohr circle