fischer Earthquake-proof Retrofitting Solutions - A New Hope for Millions of Existing Buildings in India

A research project carried out by the fischer Group of Companies in collaboration with  Purdue University (USA) has shown that existing buildings can be made significantly more  resistant to seismic forces through targeted retrofitting measures. In earthquake-prone  regions, such solutions have the potential to improve structural safety and help protect  lives. The severe earthquakes of recent days have once again tragically demonstrated  how vulnerable people are in seismically active regions. The images of destroyed homes  and the high number of casualties are deeply distressing – and raise a pressing question:  how can such disasters be prevented in future, or at least their consequences mitigated?

fischer earthquake-proof retrofitting solutions

Part of the answer lies in the so-called building stock. While new buildings today are  subject to strict seismic standards, millions of older structures worldwide were built long  before modern earthquake-resistant design standards came into force. It is precisely in  the places where people live and work that the necessary protection is often lacking.

 
The real risk lies in the existing building stock 
Around 500,000 earthquakes are recorded worldwide every year (Source: US Geological  Survey). Densely populated regions along the Pacific Ring of Fire, in the Mediterranean,  in the Himalayan region and in Central America are particularly at risk. Furthermore,  human activities such as geothermal energy extraction, fracking and the construction of  large reservoirs can also trigger earthquakes. 

Demolishing and rebuilding all at-risk buildings is not a realistic option – it would be too  expensive, too time-consuming and too resource-intensive. The crucial question is  therefore: how can existing buildings be retrofitted so that they can withstand such  events and help protect human lives? 

Research involving large-scale tests on full-scale structures 
To answer this question, the fischer Group of Companies, in collaboration with its partner  university, Purdue University (USA), carried out a research project involving tests on full scale reinforced concrete structures. The project was led by Prof Akanshu Sharma,  Associate Professor at Purdue University and former Endowed Professor at the Institute of Materials Science at the University of Stuttgart. The focus was on so-called beam column joints: the connection points between beams and columns. In the event of an  earthquake, these can quickly become weak points in a structural system.  

“These beam-column joints in RC frame structures are subjected to particularly high  stresses and significant force caused by horizontal loading during an earthquake.”  explains Dr Margaritis Tonidis, a former PhD Candidate at Purdue University and leading  Project Engineer of the project. If these joints fail, an entire building can collapse. 

Strong where it matters 
The solution tested addresses precisely these critical points: so-called haunch elements  – in this case, steel diagonal braces – are integrated into the existing structural framework  using injection mortar and threaded rods, thereby specifically reinforcing the joints on  site. Dr Erik Johannes Stehle, Head of Development FiXperience at fischer emphasized “The tests have shown that the earth-quake resistance of existing  buildings can be significantly increased if the critical points in the load-bearing  structure are specifically identified and reinforced.” The key advantage is that the  retrofitting can be carried out with relatively little intervention in the existing structure.  Residents and users therefore need not fear extensive alterations. 

From experiment to practice 
Under seismic loading, a significantly improved performance was demonstrated,  particularly at the joints. This successful scientific validation is now being translated into  practical application for existing buildings. The results offer hope: they show that realistic  and affordable ways exist to make older buildings more resilient – and thus significantly  reduce the number of casualties in the event of an earthquake. 

Mr. Mayank Kalra, Managing Director, fischer India, says, “India has a vast building  stock, including structures that were constructed before today’s seismic design  standards were introduced. This research is particularly relevant for India, given the  country’s vulnerability to earthquakes across several regions. Retrofitting existing  buildings at critical structural points can offer a practical and more sustainable  alternative to demolition and reconstruction, helping improve resilience while  minimising disruption to occupants. At fischer, we see this research as an important  step towards bringing scientifically validated retrofitting solutions closer to real world application in India, with the potential to strengthen existing structures,  protect lives and contribute to safer, more resilient communities.” 

fischer Building Materials India Private Limited 
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