Experimental investigation of the rocking response of SDOF systems on sand

Highly inelastic foundation response is inevitable in a strong earthquake event. Shallow foundations supporting bridge piers or building columns and frame walls may experience sliding and/ or uplifting from the supporting soil or bearing capacity failure. However, such non-linear foundation response may be beneficial for the overall system performance since high energy dissipation occurs at the foundation level, thus limiting the ductility demands exerted on the structural components. This paper presents an experimental investigation of the rocking response of surface foundations on dry sand. A comparison between centrifuge tests and equivalent reduced scale 1 g slow cyclic tests is presented in order to explore the effects associated with the low confining stresses prevailing at 1 g test conditions.