Seismic Interaction between Soil and Structures having Two Foundation Levels

Abstract

The seismic behavior of retaining walls has been the subject of considerable geotechnical research over the last century since the early attempts by Okabe (1926) and Mononobe and Matsuo (1929) by developing the well-known M-O method. Retaining walls are classified, from seismic behavior perspective, into yielding and non-yielding walls. Basement walls are restrained at top and bottom but are relatively free to displace along their entire height depending on the flexure stiffness. Hence, basements walls are neither yielding nor completely non-yielding, and the widely used methods in the literature for yielding (e.g. M-O method) and non-yielding (e.g. Wood, 1973) walls should not be used to evaluate the seismic behavior of basement walls. The seismic behavior of basement walls is further complicated in cases where the basement does not occupy the whole structure’s footprint. In such case, the foundation stresses from the upper foundation level have remarkable effect on the seismic response and behavior of basement walls. This research study investigates the seismic response of basement walls by numerical analysis. In particular, the study focuses on basement walls occupying part of the structure’s footprint area, i.e. basement walls in