Evaluation of the performance of a 10 story steel structure with Base Isolation under blast loads

Abstract

The occurrence of terrorist attacks and bombings in recent years has shown the importance of constructive safety against blast loading more than ever before. Blast is one of the rare events that can cause many damages to the buildings during their lifespan. Investigating the behavior of structures under blast load can help to make managerial decisions for the safety of structures. In this research, the behavior of steel structures with seismic isolation of LRB type in different explosion scenarios was investigated using the concept of energy balance. Two types of 10-story steel structures with isolated and fixed-bases have been subjected to 12 types of blast loadings after designing. Initially, the performance of the structures under these loadings and the rotation of the plastic joints and drift of structures were evaluated and then, using the time history curves the depreciated and absorbed energies of the structure, balance of energy in each scenario are studied and the role of isolators in the creation of energy balance is investigated. The results show that the existence of depreciated plastic strain energy in seismic isolators reduce depreciated energy in other members and the amount of their damage will be decreased. Also, the percentage of internal energy in the energy loss caused by the explosive charge has also been evaluated.In structures with a seismic separation, the energy loss ratio of the elements of the beam and column is less than that of the fixed foot structure.