Calculation of passive earth pressures on retaining wall considering soil arching effects of backfill clayey soil

The nonlinear phenomenon which the passive earth pressure behind the retaining wall of both sand and cohesive soil is nonlinear distribution could be explained by the soil arching effect theory. The formula which calculated passive earth pressure coefficient of which assumed the stress state method and the soil wedge static equilibrium method were derived considering the soil arching effect, assumed arch as circle and the angle of slip surface as Rankine's theory. Then, the distribution of lateral earth pressure considering the soil arching was derived by the above formulations; also the formulas that calculating the magnitude and the point of application of lateral passive earth pressure were derived. The accuracy of proposed method is confirmed by comparing with the experimental tests and values from existing equations. Finally, the trends of distribution and the height of total passive earth pressure of clayey soil are studied; distribution of passive earth pressures considering the soil arching is likely an exponential curve; and the height of resultant earth pressure point is gradually reducing with increasing the ratio of soil-wall friction angle to internal angle δ/φ.