Seismic analysis of cantilever retaining walls

Cantilever retaining structures are susceptible to failure during strong earthquakes because of seismically induced lateral earth pressures and inertial effects on the wall. Dynamic non-linear finite element analyses have been performed in the time domain to assess the dynamic behavior of cantilever retaining walls subjected to earthquake loading. The earthquake loading records used in the analyses were from actual measured earthquake acceleration time histories. A parametric study has been performed to study the most effective variables controlling the behavior of cantilever retaining walls. These variables are classified into five main groups. The first group, soil properties, includes the soil angle of internal friction, soil modulus, coefficient of lateral earth pressure at rest, Poisson's ratio, soil dilation angle, and coefficient of friction between the wall and soil. The second group, wall configuration, contains wall height, base width, wall thickness, the eccentricity of the wall relative to the base, and presence or absence of a heel attached to the base. The third group, earthquake load, consists of the earthquake source type and the maximum acceleration of the earthquake motion. The fourth group, damping properties, includes soil damping properties and effects of the soil damping and concrete damping on earthquake performance of the structure. The fifth group, crack model, includes non-linear concrete wall concrete material properties such as concrete compressive strength, yield strength in reinforcement steel, and the percentage of reinforcement in the wall. In this study, the lateral and vertical total and plastic deflection of the wall have been evaluated. The distribution and center of gravity of the seismic lateral earth pressure loading behind the wall are discussed. The distribution of the bearing stress below the wall base has been developed. The vertical normal stress and the moment distribution in the wall have also been evaluated. A design manual has been developed for evaluation of the effect of earthquake loading on the behavior of the cantilever retaining walls, and a step-by-step design procedure was developed. An interactive software package has been developed to guide users through the analysis and design of cantilever retaining walls subjected to seismic loads.