Numerical Study on the Seismic Response of Structure with Consideration of the Behavior of Base Mat Uplift

Abstract

The foundation might be separated from the supporting soil if the earthquake is big enough, which is known as base mat uplift. This paper proposed a simplified calculation model in which spring element is adopted to simulate the interaction between soil and structure. The load-deformation curve (F-D curve) of the spring element can be designated to represent the base mat uplift, in which the pressure can be applied while tensile forces are not allowed. Key factors, such as seismic wave types, seismic wave excitation directions, seismic wave amplitudes, soil shear velocities, structure stiffness, and the ratio of structure height to width (H/B), were considered in the analysis. It is shown that (1) seismic wave type has significant influence on structure response due to different frequency components it contained; (2) the vertical input of seismic wave greatly affected structure response in vertical direction, while it has little impacts in horizontal direction; (3) base mat uplift is easier to take place in soil with higher shear velocity; (4) structure H/B value has complicated influence on base mat uplift. The outcome of this research is assumed to provide some references for the seismic design of the structure due to base mat uplift.