Journal of Civil Engineering Researchers
Volume:3 Issue: 3, Summer 2021

An earthquake is one of the most common natural phenomena, which causes a lot of human and financial losses due to the impossibility of predicting and preventing it. Iran is one of the regions with high earthquake risk in the world due to special tectonic conditions and the existence of active faults and high seismicity. New methods in earthquake engineering, especially in recent decades, have had a significant impact on reducing seismic damage to structures. Over the years, researchers have introduced a varietyofmethods to reduce earthquake damage to structures. However, the existence of economic issues arisingfrom the use of innovative equipment has always been the subject of public debate. Structural control is one of the effectivemethods of earthquake engineering to reduce seismic response. Structural control means that the characteristics of the dynamic behavior of the structure are adjusted in such a way that the response of the structure does not exceed the allowablelimits due to external stimuli. One wayto control the structural behavior is to use dampers. In this research, the performance of a multi-level pipe in pipe damper and a new brace-type slit damper in structures is investigated. In this paper, first, four structural models including two 5 and 10 story models with the same plan and two 10 and 15 story models with the same plan are modeled in SAP software. Then the same structure is examined by considering the pipe damper in the pipe. The results show that the presence of this type of damper reduces the structural responses,including drift and displacement of the maximum roof to an acceptable extent. Also, according to the models, the performance of brace-type slit damper was better than multi-level pipe in pipe damper.©2021Journals-Researchers.All rights reserved.

A chain reaction or collapse-spreading in which, under certain causes, local damage occurs in a relatively small area of the structure and under certain conditions this local damage spreads to other parts of the structure and ultimately leads to overall collapse of the structure is called progressive collapse. The main feature of this phenomenon is that the final collapse is not commensurate with the initial collapse; severe incidents such as terrorist attacks, vehicle collisions and explosions, etc.often damage the building and collapse in one or more vertical bearing parts leads to a serious threat. The following article provides an overview of the main research and developments in 2019 and 2020 regarding progressive collapse such as progressive collapse assessment, experimental testing, and numerical modeling.© 2017Journals-Researchers. All rights reserved.