ANALYSIS OF THE COLLISION EFFECT FOR ADJACENT STRUCTURES IN THE TIME-FREQUENCY DOMAIN

Abstract

Many reinforced concrete structures are built side by side in our cities. There are very few applications of earthquake joints in adjacent apartment buildings, most of them were constructed completely adjacent. Adjoining buildings or any property should be protected from damage or collapse during construction, restoration and demolition work. In case of the static condition, protection must be supplied for foundations, walls and roofs. We have already observed many building collapses in Turkey with a great number of life lost. For the constructed buildings, there is a need to understand the structural system of an existing building to manage risk. In case of earthquakes like dynamic loading, earthquake joints are essential. The Turkish Building Earthquake Code (TBEC) 2018 requires calculations of vertical joints for some types of structures. Earthquake joints should be left in the gap calculated for structures of some height. It is thought that this gap will prevent the structures from colliding. However, it has been the subject of research how the performance of the building will change when it is produced adjacent or when floor offsets cause collisions at earthquake joints. In this study, structures of different heights were analyzed in the time domain for specific earthquake motions. Collision situations of more than two buildings are discussed by making a street model. Structural performances of discrete and adjacent structures obtained from nonlinear analysis were compared. The motion parameters obtained from the structures were analyzed in the time-frequency domain by wavelet and Hilbert transforms. To determine the effects of earthquake joints, condition assessment and damage detection studies were carried out and the sufficiency of seismic joints was discussed.