Change of Structural Concept and Number of Stories of a Building Under Construction with Application of the Roof Isolation System Excluding Strengthening of Already Constructed Bearing Structures
Publication Date: 27/09/2018
Author(s): Mikayel Melkumyan.
Volume/Issue: Volume 1 , Issue 1 (2018)
Abstract:
One of the key features of anti-seismic design of buildings is the possibility to control inertial load values depending on the structural concept of the buildings. In the 1950s, when the spectral theory of seismic stability was developed, the flexible ground floor was regarded as the basic approach for reducing the seismic action level. However, the consequences of strong earthquakes such as the 1963 Skopje, the 1988 Spitak or the 2008 Sichuan Earthquakes, etc. have shown that in this case the bearing structures (mainly columns) of the ground floors were severely damaged and further use of buildings was impossible despite the upper floors were well preserved. Therefore, continuing efforts are made by researchers to determine the most efficient methods of seismic protection of buildings for their practical application. One of these methods is the application of tuned mass damper (TMD), a passive vibro-protecting device, known as a single degree-of-freedom appendage of the primary structure. Dampers have been widely investigated in connection with seismic protection problems. The author of this paper has already accumulated considerable experience in protecting of existing buildings by application of innovative seismic isolation technologies in the form of additional isolated upper floors (AIUF), as well as in the form of isolated upper slabs (IUS). These concepts represent the roof isolation technology. Developed structural solutions of AIUF or IUS are bringing to creation of diverse types of TMDs on the top of the existing buildings. Such systems give the opportunity to efficiently control the vibrations. Based on this experience the number of suggestions were made which allowed to solve the set task for the building under consideration in the given paper. Structural concept of earthquake protection system designed for application in the existing reinforced concrete building together with some other measures is described. The building is currently under construction in the city of Yerevan, the capital of Armenia. This research and design work are unique as for the first time in construction practice substantial changes to the initial design were requested in the course of construction works.
