Performances of Various Base Isolation Systems in Mitigation of Structural Vibration Due to Underground Blast Induced Ground Motion

A comparative study is carried out on the performance of various elastomeric and frictional base isolation (BI) systems in the vibration mitigation of structures subjected to underground blast induced ground motion (BIGM). The parametric sensitivities of the base isolated structures to variations in the design parameters of the isolators are examined for different intensities of blast input. Results indicate that substantial reductions in both the acceleration and displacement responses of the structure can be achieved by the different base isolators. Generally, the Electricite de France (EDF) base isolator produces higher peak response reductions. However, peak bearing displacements are also largest here. The pure friction (P-F), resilient-friction base isolator (R-FBI) and friction pendulum (FP) systems produce lower values of response reductions but peak bearing displacements as well as residual displacements of isolators are also low. The New Zealand (N-Z) system provides good response reductions with a low to moderate value of peak bearing displacement. The present study indicates how a proper selection of the type of BI system with suitable design parameters can mitigate structural vibration due to different intensities of BIGM and restrict the unwanted characteristics of large isolator displacement and its permanent deformation.