Estimating Bearing Capacity of Strip Footings over Two-Layered Sandy Soils Using the Characteristic Lines Method

Abstract

A study on the bearing capacity of strip footings over sandy-layered soils has been conducted using the stress characteristic lines method. Traditional bearing capacity theories for specifying the ultimate bearing capacity of shallow foundations are based on the idea that the bearing layer is homogenous and infinite. In practice, layered soils are mainly being used. The stress characteristic lines method is a powerful numerical tool that can solve stability problems in geotechnical engineering. In the present paper, an appropriate algorithm is derived for estimating the static bearing capacity of strip footing located on two-layered soils using the stress characteristic lines method. Numerical and experimental examples are presented, to validate the proposed algorithm. Graphs and equations illustrate the effective depth of strip footings located on two-layered soils. If the friction angles of the top and bottom layers are 30° and 35°, respectively, the depth effect of the top layer is estimated to be 0.76 of the foundation’s width.