The above relations can be applied to a rectangular footing (of the same height, h) using
an equivalent Be that is determined by equating the moment of area of the surface of the
footing about the y-axis (Iy) to that of the equivalent circular footing. Thus
3.5.3 Sliding Oscillations
A mass-spring-dashpot analog was developed by Hall (1967) to simulate the horizontal
sliding oscillations of a rigid circular footing of mass m (Figure 3.25). This can be
expressed by
If the foundation is circular, the spring and the damping constants are given by