Framed Infill Network
Global researchers, engineers, architects, builders and officials developed new design guidance to improve seismic behavior of concrete frames with masonry infill walls, a common building type.
A building constructed with concrete frames and masonry infill walls in Thimphu, Bhutan. Photo: Janise Rodgers
In the last decade, tens of thousands of people died during earthquakes because a particular type of building collapsed on them. Poor construction or lack of engineering sometimes caused these buildings to fail, but in many cases blame lies with the design itself.
We formed a network of international specialists to improve earthquake resistance of a common building type, concrete-frame-with-masonry-infill-walls. Techniques they developed, if adopted, will advance global earthquake safety.
Buildings of concrete-frame-with-masonry-infill-walls are prevalent in urban regions where earthquakes are a threat--Asia, Central and South America, and the Mediterranean. Construction is fast, easy, and low cost. The buildings range in size from one to 20 stories and are used for housing, offices, shops, and schools. A large and increasing number of people inhabit them.
One problem in these buildings is that there are few walls at the ground story (used for shops or parking) and many heavy walls in apartments above. Earthquake damage tends to concentrate in the weaker, more flexible ground story, which was not designed to withstand such forces. The frames may also lack integrity, which increases vulnerability.
The Network developed affordable, modest changes to current practices. These techniques help engineers and builders plan masonry infill walls as intentional structural elements. For the improved structures, the Network coined the term "framed infill buildings."
We created a design manual that presents five strategies to design framed infill buildings. The manual explains why a strategy will or will not be effective in certain cases--and when to use a different structural system entirely. Available materials, local skills, seismic hazard, building location, and building use factor into the choice of strategy.
Members of the Framed Infill Network are spread around the globe. Geoscience researchers, practicing engineers, architects, builders, and building officials collaborate electronically in small groups. Their fruitful exchange has bred cost effective and innovative approaches, such as a "rocking spine" design strategy.
The Network conducts research, engineering design, construction, education, outreach and training. A new focus in 2015 added research on hillside buildings.
Funded by the National Academies and the Earthquake Engineering Research Institute.
Research on improving hillside buildings is funded by Thornton Tomasetti Foundation.
Conceptual Design Guidance for New Framed Infill Buildings A design manual to help engineers understand and apply techniques developed by the Framed Infill Network.
Framed Infill Network website
Technical literature surveys related to infill frames