Experimental Analysis and Theoretical Modelling of Polyurethane Effects on 1D Wave Propagation through Sand-Polyurethane Specimens

ABSTRACT

This paper shows the experimental results of impact hammer tests conducted on sand and composite sand-polyurethane samples at different confining pressures. It was found that polyurethane can mitigate the propagation of waves generated by an impact, thereby influencing seismic isolation. Also, accelerations in the composite samples were reduced in relation to the percentage of polyurethane present. A theoretical lumped-mass model (calibrated based on the experimental results) interpreted the experimental results and enabled an in-depth parametric analysis. This analysis shows that the proposed isolation method is efficient, as the damping coefficient of the polyurethane and the soil/polyurethane impedance ratio increased.

KEYWORDS:

• Wave propagation
• seismic apparatus set-up
• geotechnical seismic isolation
• polyurethane foams
• impact tests