Forced vibrations laboratory tests held by telepresence for the first time since the foundation of IZIIS in 1965
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Forced vibrations laboratory tests held by telepresence for the first time since the foundation of IZIIS in 1965

After the successfully realized INMASPOL (INfills and MASonry Structures by Deformable POLyurethanes in Seismic Areas) project in the framework of SERA (Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe) research project in 2019, the mutual collaboration between Cracow University of Technology – CUT and the Institute of Earthquake engineering and engineering seismology – IZIIS in Skopje went further on.

The purpose of the activities undertaken at the request of TUK, i.e., additional tests on the model from the INMASPOL project, was to continue assessing the efficiency of the innovative  method for seismic protection of structures.  This time, through tests on a full scale model of RC elements with masonry infill by means of the forced vibration method.  By placing the model aside from the shake table, the risk was considerably reduced and  a possibility for its testing and causing serious damage was created. With the last tests inclusive, the model was completely destroyed considering that all  joints lost their bearing capacity and the structure behaved as a mechanism. Upon loss of bearing capacity of composite materials, the block bricks of the partition walls also suffered individual  displacement irrespective of each other.

For the first time since the foundation of the Institute in 1965, due to the current global Covid 19 pandemic, the experimental activities in the laboratory were successfully performed by virtual presence of all stakeholders. Virtual presence was enabled through three high resolution adjustable cameras and a special communication link of Microsoft Office 365 Teams and Stream applications.

In the period to come, detailed  analyses of the results obtained by the seismic shaking table  tests and the tests  by use of the forced vibration method will be carried out, hopefully resulting in further fruitful scientific cooperation.

Experimental activities in framework of SERA - INMASPOL project

Experimental activities in framework of SERA - INMASPOL project

The Institute of earthquake engineering and engineering seismology in Skopje as a part of SERA (Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe) participated in three scientific projects ( INMASPOL, SC-CBF and Influence of the floor-to-wall interaction on the seismic response of coupled wall systems) as research centre offering its capacities and laboratory equipment from the department Dynamic testing and informatics.

The project assessed the efficiency of the innovative intervention method through testing of full-scale masonry infilled RC building on shaking table. The seismic tests validated in-plane and out-of-plane infill performance when modified, repaired, or strengthened with PUFJ (Polyurethane flexible joints) and FRPU (Fiber reinforced PU) systems. The project was successfully realized, and valuable data was obtained.

The test specimen was one fully symmetrical 3D frame of one storey with 4 RC columns, 4 beams, a slab and 4 infill masonry walls constructed, all designed according to current Eurocodes. The real scale building had plane dimensions of 2.7×2.7m and total height of 3.25m. It was exposed to many seismic tests on the shaking table, using the scaled Kefalonia earthquake record as well as random and sine sweep excitations to determine the change of the dynamic characteristics.

The Dynlab – IZIIS team expresses gratitude to the people and institutions responsible for realization of this project. It was pleasure working with Assis. Prof. dr. Theodoros Rousakis from Democritus University of Thrace as Transnational User and as User group members Prof. dr. Alper Ilki from Istanbul Technical University, Turkey, Prof. dr. Arkadiusz Kwiecień from Cracow University of Technology (CUT), Poland, Assoc. Prof. dr. Alberto Viskovic and Assis. Prof. dr. Fabio Rizzo from G. D’Annunzio University of Chieti – Pescara, Italy, Miha Kramar from Slovenian National Building and Civil Engineering Institute, Ljubljana, Slovenia, Assis. Prof. dr. Bahman Ghiassi from University of Nottingham, UK, University Park Nottingham, UK, Prof. dr. Andrea Benedetti and Adj. Prof. dr. Camilla Colla from Alma Mater Studiorum-Universita’ di Bologna,Italy, Maciej Karpała from SIKA Poland Sp. z.o.o., Cracow, Poland, Kothalis Agis from KEBE SA, Head offices-Factory Nea Santa, Kilkis, Bogusław Zając from FlexAndRobust Systems Ltd, Cracow, Poland and Assis. prof. Matija Gams from University of Ljubljana (UL), Slovenia.

The project leading to this application received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 730900.