Geotechnical Seismic Isolation (GSI) is an innovative technique for protecting structures in earthquake-prone areas. The main idea is to improve the foundation soil so that seismic energy is partially dissipated within GSI before being transmitted to the structure. Among other materials proposed for foundation soil improvement, gravel-rubber mixtures (GRMs), with rubber grains manufactured from end-of-life tires, have attracted significant research interest thanks to their good mechanical properties. GRMs also represent a modern recycling system to reduce the stockpile of scrap tires worldwide. The present study investigated numerically the effect of a GRM layer located underneath the shallow foundations of a real structure. The structure is a typical reinforced concrete building in southern Italy. A Finite Element Modelling (FEM) was carried out to evaluate the overall static and dynamic behaviour of the soil-GRMs-structure system. Three FEM models were performed with and without the GRM layer, varying the GRM layer thickness and the seismic inputs. The comparisons among the models allow us to assess the performance of the GRM underneath the foundations as a new eco-sustainable solution for the seismic isolation of structures.

Worldwide, an increasingly huge number of end-of-life tires (ELTs) are disposed of in landfills, illegally dumped, or otherwise unaccounted for, which causes significant environmental and s...

Based on criticisms raised in the past by researchers about the effectiveness of the design rules reported in the European seismic code for the design of concentrically braced frames, a new design procedure has been proposed and included in the upcoming version of Eurocode 8. The upcoming version of Eurocode 8 is in the enquiry stage. Hence, it is important to evaluate the effectiveness of the design procedure reported in the code using accurate numerical models and seismic inputs. In the present paper, a four-story building with concentrically braced frames in the chevron configuration is designed according to the upcoming version of Eurocode 8. A seismic performance assessment is carried out by the means of multiple-stripe analyses performed on refined numerical models. The seismic input is defined based on one-dimensional local site response analyses. The numerical analyses prove that the use of local site response analysis to properly account for the soil-filtering effects is of paramount importance, and that the design procedure reported in the upcoming version of Eurocode 8 for chevron concentrically braced frames leads to reasonably low probabilities of exceeding the considered limit states.

Soil–rubber mixtures have been proposed as cost-effective seismic and dynamic risk mitigation techniques. The granulated rubber used for these mixtures is obtained from end-of-life tires, allowing for stockpiles of waste rubber tires to be recycled. To date, most of the research has focused on the mechanical properties of sand–rubber mixtures, while limited studies have been performed on gravel–rubber mixtures (GRMs). In particular, GRMs with well-graded gravel (wgGRMs), which are of significant practical interest due to their availability, have only been poorly characterised. As part of a wider investigation aimed at facilitating the use of wgGRMs as geotechnical dynamic isolation systems, this paper presents bender element and small-strain cyclic triaxial test results performed on mixtures with 25%, 40%, and 55% volumetric rubber content. It is found that, thanks to their excellent energy absorption properties, wgGRMs can be efficiently adopted as geotechnical dynamic isolation to mitigate seismic risk of and anthropically induced vibrations on existing and new structures/infrastructures. Their easy implementation, low-cost, and widespread availability further facilitate their use.