Seismic isolation for existing masonry houses in Groningen/ NL combined with thermal upgrading

Induced earthquakes, caused by the winning of natural Gas in the North of the Netherlands (Groningen province), are causing significant damage to the existing, often relatively weak, masonry buildings. This seismic hazard and seismic rehabilitation problem in the Groningen area involves much more than just a technical seismic safety problem. Many different stakeholders are involved, not in the least the local population, attached to their local environment and their often privately owned houses. The proposed seismic rehabilitation method can preserve and improve these masonry housing units, by combining seismic isolation with thermal insulation. Core of the approach is applying seismic base isolation by removing the existing, often poor quality, timber floor structure, and, making new foundation footings with a new thermal insulated structural (reinforced concrete) ground floor. First calculations indicate that the rehabilitation method can significantly reduce the seismic impact and seismic hazard of these existing masonry houses.