Sustainable use of End-of-Life-Tires (ELTs) in a vibration isolation system

Abstract

Huge stockpiles of End-of-Life Tires (ELTs) are of major global concern. This paper investigates and helps to demonstrate the beneficial utilization of ELTs to provide geotechnical seismic isolation (GSI) of machine foundations located on a rubber-soil mixture (RSM). A series of laboratory tests is conducted to extend the understanding of RSM behavior beyond that previously elaborated, particularly by demonstrating the efficiency of the GSI-RSM system and by defining its optimal parametric values. The results indicate that increasing the thickness of the RSM layer and soil cap, along with the addition of rubber content, up to the optimum values lead to enhanced performance. Beyond these optimum values, the benefits start to decrease. For the determined optimum rubber content (8%), RSM layer thickness (0.1B), and soil cap thickness (0.15B) at a vibration moment level of 0.17 N.m, the GSI-RSM system achieves maximum reductions of 36%, 43%, and 77% in resonant frequency, resonant displacement, and resonant acceleration, respectively, compared to untreated beds. Moreover, the GSI-RSM system effectively reduces the developed peak particle velocity (PPV) and kinetic energy, independent of the excitation frequency. The increased damping and significant energy dissipation demonstrates the system’s effectiveness in mitigating vibrations. This environmentally-friendly technique presents a low-cost alternative for improving the vibration behavior of soil beds. It provides the basis for the wider adoption of ELTs for GSI, for machine foundations and for other infrastructure projects with similar soil vibration concerns, including building foundations, transportation infrastructure and industrial facilities. In this way the research contributes to the growing body of sustainable practices in the construction industry.