Comparative Analysis of a Concrete Structure Constructed with Conventional Technique and with Base Isolation

Base isolation is a type of building element that tries to reduce the effects of seismic lateral loads on the structure, rather than increasing the strength against these loads. In this design method, it is aimed to minimize the relative displacement between the floors during the earthquake wave by obtaining a separate working form of the building sections over the foundation. In this article; an existing school structure consisting of frames is firstly solved by the traditional built-in foundation based system, the mode shapes are found and the building periods are obtained. For this, earthquake loads are distributed along floor heights using the static equivalent earthquake load method, so structural elements with capacity problems are found. Then, 0,005 second time-history acceleration which is recorded at 1999 Marmara earthquake in Düzce meteorology station, is reflected and analyzes are repeated with the non-linear time-history method and the two methods are compared. In the second stage, the structure is analyzed by using the time-history method with the addition of lead-core rubber base isolators. Thus, the comparison of the mode shapes and the changing periods of the base isolator system with the conventional method is made. As a result, a significant increase in the period of the isolation system construction and the decrease of the spectral accelerations and the shear forces coming to the structure are observed, and it is seen that the sectional deficiencies that existed in the first case are removed