Improvement of Structures with Progressive Damage Using Seismic Isolation System

Abstract

There is always a need to improve the structures for many reasons, including changing the use, changing the design ‎regulations, increasing the life of the structure, and improper implementation of the structures.‎‏ ‏One of the most ‎influential parameters in the selection of the improvement method is the lateral stiffness of the target structure, ‎which is determined according to the lateral bearing system of the structure. There are many methods for ‎improving structures, including the use of steel jackets to increase the load capacity of columns and the use of FRP ‎fibers, etc.‎‏ ‏The transfer of ground movement to the structure can be controlled with the help of the base seismic ‎isolator system at the base of the structure; the base seismic isolator isolates the upper structure from the ground ‎shaking movements so that the destructive forces of the earthquake do not enter the building or to a significant ‎extent be reduced‏.‏‎ The Malaysian Rubber Materials Research Company in England has produced a type of ‎elastomer with high damping. Using this elastomer, a rubber seismic isolator system with high damping has been ‎used for the seismic isolator of buildings. In some systems, the Teflon layer is used to cause slippage between steel ‎sheets.‎‏ ‏A central lead core is provided to control lateral displacement and return the system to its original state.‎‏ ‏Progressive failure is the failure of the entire structure, or a relatively large part of it, caused by events that damage a ‎part of the structure and the inability of adjacent members to redistribute the overload through a path that can ‎maintain the stability and continuity of the entire structure.‎‏ ‏Progressive failure may occur as a result of abnormal ‎loading such as explosion, severe fire, vehicles hitting a part of the structure, etc.‎‏ ‏The lateral bearing system is part ‎of a structure that is responsible for resisting lateral loads and directing them from a safe path to the foundation ‎‎(lateral forces can include wind, earthquake, or other forces).‎‏ ‏Earthquake-resistant elements should be considered ‎in such a way that the torsion caused by these effective and resistant forces in the floors is minimized.‎‏ ‏For this ‎purpose, it is suitable for the distance between the center of mass and the center of stiffness in each floor and ‎extension to be less than 5% of the dimension of the building in that extension.‎