An analytical solution procedure is described to estimate the developed passive lateral earU1 pressures behind a vertical rigid retaining wall rotating about it toe or top into a mass of cohesion less soil. Various stages of wall rotation, from an at-rest state to an initial passive state to a full passive state, are considered in the analysis. A condition of failure defined by u modified Mohr-Coulomb criterion and equil. ibrium conditions are used to obtain the necessary equations for solution. The development of friction along the wall surface at various tage of wall rotation i also taken into account in the analy is. Finally, the results predjcted by the developed method of analysis are compared with those obtained from the experimental model tests on loose and dense sand. The comparisons show good agreements at various stages of wall movement.

The estimation and prediction of the lateral earth pressure developmelll have been among the mo t important aspects in geotechnical engineering. The development of active lateral earth pressures in particular has received a considerable amount of attention, because a majority of retaining structure are designed based on the active lateral earth pressure due to the tendency of outward movement. However, design of many geotechnical structure require con~ ideration of pa sive lateral earth pressures. Several analytical and experimental studies have been made in the pa t to inve tigate the magnitude and distribution of pa ivc lateral earth pres ure. developed behind the retaining walls (/-5). These studie have been helpful for understanding the mechanism of the development of passive lateral earth pressures. However. most of the analytical studies fail to provide adequate comparisons with experimental model test result. This failure may be in part due to the uncertainties associated with the variations of the soil strength and the wall friction with respect to the magnitude of wall movement. A need for an analytical solution that takes into account the variation of material properties at various stages of wall movement therefore has been realized. This paper presents an analytical solution method that describes the transition of the pa sive lateral earth pres ure from an at-rest state to an initial passive state to a full pa ive tate behind a vertical rigid wall rotating about its toe or top into a mas of cohcsionlcss soil. The at-rest state i defined as a stage of no wall movement. The initial passive state refers to a stage of wall rotation when only the soil element either at