An innovative approach for reducing the seismic risk of existing buildings and historic sites

摘要

The seismic risk is one of biggest challenges for civil engineers, and a number of mitigationrnstrategies have been developed in time with reference to existing or new buildings. Nowadays, refinedrntechniques based either on structural reinforcement or seismic isolation exist to protect new and existingrnstructures from seismic shaking. This paper presents some results of a research activity in progress at thernUniversity of Napoli Federico II (Italy), aimed to check the effectiveness of an innovative approach forrnreducing the seismic risk by using soft grouting mixtures installed at an optimum depth in the foundationrnsoil. The basic idea is that a thin grouted layer, with a dynamic impedance much smaller than that of thernsurrounding soil, will filter most of the seismic ground motion, with very little energy being transmittedrnto the overlying soil. The effectiveness of the insertion of a soft grouted layer in the range of frequencyrnaffecting the response of squat buildings was numerically tested via a parametric analyses, with referencernto a simplified one-dimensional scheme.