Seismic isolation using recycled tire-rubber
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Date
2017
Journal Title
Journal ISSN
Volume Title
Publisher
National Information Centre of Earthquake Engineering
Abstract
Geotechnical seismic isolation using rubber-soil mixtures appears to be a promising alternative to protect structures deployed over large extensions of land, such as low-income condominiums or industrial plants. The use of isolating soil layers may have several advantages and trade-offs in comparison with conventional seismic isolation. It is apparent that some of the advantages are the protection given to whatever is erected on top of a mixed soil layer, the avoidance of maintenance needed for the isolation system, the reuse of an environmentally unfriendly material through recycling, and the potentially lower cost per square meter. The usefulness of the proposed geotechnical seismic isolation concept is demonstrated by means of an inelastic model consisting of a simple linear structure underlain by a non-linear rubber-soil mixture. Layers of variable depths are considered and evaluated for a suite of 60 different seismic records. It is shown that an underlying layer of rubber–soil mixture of about 2 meters in thickness could reduce significantly the seismic demands on the structure. Indeed, the reduction ratio R of the peak acceleration obtained at the base of a structure for the three different rubber-soil mixtures (denoted as RSM-A, RSM-B and RSM-C) are R = 0.82, 0.60, and 0.46, respectively. In general, a thickness for the RSM layer between 2 and 3 meters is likely to achieve adequate levels of acceleration reduction. This is in stark contrast to the large thicknesses recommended elsewhere in the literature. Although the reduction in structural response is enhanced as the rubber content in the mixture is increased, a rubber content as low as 15-25% is found to be enough to attain useful reductions in response.
Description
Keywords
Geotechnical seismic isolation, Non-linear inelastic modeling, Rubber-soil mixture, Recycled tire-rubber