Insight into enhancing foundation stability with rubber-soil mixtures: A nanofriction study

Abstract

Ground vibration during earthquakes can lead to loss of soil strength and structural damage. Rubber-soil mixtures (RSM) show promise in mitigating the residual ground deformation under dynamic loading. The influence of clay minerals on soil frictional strength and system stability is essential in the context of earthquake mechanics. This study employs molecular dynamics (MD) simulations to investigate the friction behavior of the rubber-clay interface within the RSM system. The results indicate a direct correlation between normal stress and friction force, with denser soil systems exhibiting higher friction forces, analogous to natural soils. The increase in friction can be achieved by compacting the rubber and clay components in the RSM systems. The inclusion of rubber in the RSM significantly reduces the stick-slip motion at the montmorillonite-rubber interface, providing a damping effect that reduces the intensity of the stick-slip vibration during sliding. The friction force between the montmorillonite and rubber exhibits a velocity enhancement behavior. The higher the sliding velocity, the less the adaptation time for interfacial atoms, resulting in a higher friction force. The rubber/montmorillonite surface exhibits a higher friction coefficient at higher sliding velocities, effectively limiting the buildup of shear stress responsible for initiating stick-slip behavior. Comparisons with experimental data validate the accuracy of the calculated mechanical properties, work of adhesion, and friction coefficients. These results contribute to a better understanding of the friction behavior within the RSM system, facilitating its application in improving seismic resistance.