ABSTRACT
A series of centrifuge tests with base shaking were conducted on the 150 g-ton Centrifuge at Rensselaer Polytechnic Institute to Study the effect of biaxial base excitation on sand deposits, and to calibrate and assess the performance of the newly commissioned 2D shaker. The study used biaxial base shaking on loose and medium dense sand deposits. Two centrifuge models of 32 and 26 cm-thick, level, Nevada sand deposits, were built in 2D laminar box and subjected to base excitation inflight at 25g to simulate 8 and 6.5 m soil stratum in the field. The models were subjected to uniaxial and biaxial base shakes using artificial and real earthquake records. Several configurations of soil models were calibrated, including dry and saturated models of various densities, using pore fluid with viscosity 25 times higher than water, which was used to simulate water saturated soil deposits in the field. It was found that the acceleration amplitude increases as the base shake propagate through the soil with noticeable difference between uniaxial (1D) and biaxial (2D) models, and that the shaker is capable of applying a variety the base excitations successfully with minimal differences compared to the targeted input motion.
