Dear Asst. Prof. Şeyda Bostancı,

If you are dealing with Research on fruits&vegetables, tea, functional foods, general food science (chem&tech), AI, etc., then why you have decided to speak and open the discussion on the "Ways to make old and used buildings stronger without demolishing them"?

Anyway, it is good that you are familiar with some of the known techniques to make existing buildings stronger. However, to support the discussion you have started, I would like as an expert in seismic isolation to provide you with some information.

I am actively carrying out my research and design works in the field of seismic (base and roof) isolation. Due to my works I brought Armenia to the second place in the world after Japan by the number of seismic (base and roof) isolated buildings per the number of residents. Regarding this our Italian colleagues Martelli, Forni & Clemente have stated in their paper at the 15th World Conference on Earthquake Engineering: “It is worthwhile stressing that Armenia remains second, at worldwide level, and has the largest number of building applications of seismic isolation per number of residents, in spite of the fact that it is a still developing country”. Currently I have 261 scientific works including 12 inventions, 11 normative documents, standards and codes, and 21 books (6 monographs). My books were published in Armenia, Russia, Switzerland, Netherlands, Germany, UK, India and USA. As a principal structural engineer or member of the designers’ groups I have designed 107 earthquake resistant residential, civil, and industrial buildings for construction or retrofitting in different regions of Armenia and of Nagorno Karabakh, Russia, Romania, Peru, Kazakhstan and Turkey including those with application of developed by me seismic isolation strategies. Together with designing seismic isolation for construction of new buildings, the most important part of my works is retrofitting of existing buildings using invented by me seismic isolation technologies. I have already retrofitted in Armenia and in Russia apartment, school, bank, hospital and hotel buildings from 2 to 9 story. These are unique works, as I am doing retrofitting without moving people out, without interrupting the use of these buildings! I am also proud to say that due to my efforts Armenia is manufacturing low-cost seismic isolation laminated rubber-steel bearings of high quality. To date more than 5500 isolators were manufactured by different companies and all of them were tested in my laboratories before sending to construction sites. We are carrying out tests in accordance with the written by me and approved by the government in 2007 Armenian Standard AST 261-2007 By the frequent invitations I was conducting lectures and master classes in China (1994), Indonesia (1994), Austria (1994, 2016), Iran (1995, 1999, 2009), Italy (1996, 2001, 2010), Georgia (1997), Syria (1998), Japan (1998, 2009, 2010, 2013), Turkey (2003, 2004, 2009), Vatican (2005), Romania (2007, 2010), Peru (2016), N.R. Macedonia (2018), Greece (2020, 2022), Russia (2021, 2024), UK (2023), Kazakhstan (2024). Retrofitting of the existing buildings using invented by me seismic isolation strategies costs from 3 to 5 times less that retrofitting using old traditional technologies mentioned by you. Best regards, Mikayel Melkumyan Doctor of Sciences (Engineering), Professor Academician of the Saint-Petersburg Arctic Academy of Sciences Academician of the Athens Institute for Education and Research President of the Armenian Association for Earthquake Engineering Vice-President of the International Association of CIS Countries on Base Isolation Member of the USA Association for Science and Technology Foreign member of the Research Center of Seismic Resistant Structures of the Institute of Industrial Science, University of Tokyo Eminent Expert of the Committee of Eminent Experts in International Research Base of Seismic Mitigation and Isolation of Gansu Province in China Founder of the "Save the Yerevan Schools From Earthquakes" foundation CEO of the "Melkumyan Seismic Technologies" LLC +374 (91) 94-54-02 [email protected] www.melkumyanseismic.com P.S. In 2021 a film about me and my activities was produced by the Science Vision non-profit media organization (USA). The film is dedicated to my 70th Anniversary. You may watch the film here: https://youtu.be/9s6XA3Eg-A8

As the ancients did: for example 1) adding diagonal reinforcements between the pillars that transform a simple portal into a lattice structure; 2) including pillars and infill walls in a continuous sandwich made of two slabs, on one side and the other, in reinforced concrete with metal mesh of appropriate dimensions; 3) using modern expansive mortars to consolidate and reinforce the foundation works (especially in soils that were revealed to be more yielding than expected).

To strengthen old and used buildings without demolition, several retrofitting techniques can be applied. These include adding steel braces, reinforced concrete jackets, or fiber-reinforced polymer (FRP) wraps to structural elements. Foundation strengthening, wall anchoring, and installing base isolators can also improve stability. Seismic retrofitting is essential in earthquake-prone areas. Replacing or upgrading old materials, improving drainage, and addressing corrosion or cracks help extend the building’s lifespan. Non-destructive testing should be conducted first to assess the structure’s condition. These methods enhance safety, preserve architectural heritage, and are often more cost-effective and sustainable than complete demolition and rebuilding.