Experimental determination of kinetic friction for low-cost pvc-sand-pvc seismic isolation systems

This paper aims to experimentally determine the kinetic friction coefficient at the interface of a PVC-sand-PVC seismic isolation system using a uniaxial small-scale shaking table. The adoption of cost-effective and environmentally friendly seismic isolation methods in low-rise constructions has become increasingly essential, given the cost and implementation challenges of seismic isolation in low-income countries. The experiments were conducted to assess the variation in friction characteristics under nominal vertical stress levels of 5-10-15 kPa, representing the expected range at the foundation level for low-rise buildings. These tests were performed at sand surface densities of 1 kg/m2 and 2 kg/m2 under both dry and submerged conditions. Correlations were established between the kinetic friction coefficient, grain density, vertical pressure, and degree of saturation. The research demonstrates that the range of fluctuation in the kinetic friction coefficient is sufficiently limited, ensuring the effectiveness of the developed system, even in submerged conditions.