EFFECT OF TERRAIN PROFILE ON THE LATERAL EARTH PRESSURE OF DIFFERENT SOILS

Abstract

Unpredicted soil cave-ins in excavations and trench works are common during construction. Temporary supports are provided to prevent the collapse where the calculation of earth pressure is significant. The design of retaining walls and excavation supports depends on the earth pressure which in turn depends on the type of soil, height of the backfill, water table conditions, excavation geometry and also on the terrain profile. In the present study, it is proposed to investigate the effect of terrain profile on the lateral earth pressure of three types of soils i.e., silty sand (SM), poorly graded sand (SP) and low plasticity clay (CL). The lateral earth pressure was analyzed for the selected soils under different terrain profiles, water table conditions and earthquake forces. It was found that not only the soil type, the terrain profile is also having significant effect on the lateral earth pressure. The backfill with upward slope profiles showed higher values of earth pressure than the backfill placed at a lower level than the retaining wall. Hence, it was concluded that the terrain profile with a lower elevation than the retaining wall provides an economical design of retaining wall due to the lower value of lateral earth pressure.