ABSTRACT
The property of K, the coefficient of earth pressure at rest, in a soil mass is influenced by various factors, particularly the previous stress history. Although there have been many research studies concerning K, it was still not easily estimated either in a laboratory or in the field because the soil mass should be in an “at rest” condition. Recently, some researchers paid attention to the effects of saturation degree of soil, groundwater, and seepage on the lateral earth pressure acting on retaining structures. It was found that the earth thrust will increase when the backfill is under saturated seepage condition. Moreover, the values of K also were used as a lateral restraint factor to convert volume change to vertical swell for predicting swell behavior of soils (Manouchehrian 2008).
