Newsletter 2/2009

Earthquake-Resistant Housing for Developing Countries

By Hamid Isfahany and Georg Pegels

Despite all the research that has gone on, large earthquakes are disastrous, especially in developing countries. Earthquake-resistant housing is what is required, but it is not being built. Traditional timber-framed construction methods like those used for the traditional German "Fachwerkhaus" could solve the problem. Iranian and German researchers have hit on the unplumbed potential of ancient architecture.

Every house in the world is built to resist gravity. Not so much thought is given to horizontal forces because by comparison, the force of the wind is minimal and dangerous shockwaves from earthquakes are rare. People tend to suppress rare events. And then, suddenly, a large-magnitude earthquake costs thousands of lives. This does not have to be the case.

The idea was born during a DAAD summer school in Wuppertal while viewing up to 400 year-old timber-framed houses of the Fachwerkhaus type: young Iranian scientists discovered that the way traditional timber-framed buildings were constructed made them earthquake-resistant. Analyses of photos on the Internet confirm the point: in an earthquake, traditional timber-framed buildings remain standing when many others have collapsed.

Modern earthquake safety on the mediaeval model

The typical, largely visible diagonal braces guarantee that the vertical columns do not collapse like dominoes when the ground moves. Car bodywork proves that steel is more suitable for beams and columns of this type than wood. They encase the areas between the beams so that they do not fall out and injure people when an earthquake strikes. The spaces can be filled with soft adobe materials. This is cheaply available in many countries and also has the advantage that it absorbs shockwaves like shock absorbers. To ensure that the areas between the beams are held firmly, U- and L-shaped beams are used. This gives the choice of showing the steel as an architectural element either by a clearly-visible U-shape or an indicative L-shape. However, any compromise for the sake of cultural acceptability should not undermine the security concept which is inherent in the visibility of the structure. Thus, it is an intriguing and worthwhile academic challenge to use structural engineering to cope with non-technical problems and remove obstacles.

Iranian students constructing  a steel Fachwerkhaus in the  car park at Wuppertal  University.
Iranian students constructing
a steel Fachwerkhaus in the
car park at Wuppertal
University.
Foto: privat

Mass construction of safe housing is a decisive element in solving the core problems of countries with fast-growing populations threatened by earthquakes, i.e., unemployment and shortage of housing. Building the many houses that are lacking would create a great deal of employment in the construction industry. This was how the German "economic miracle" began! Theories are fine; putting them into practice is better. So, in summer 2007, 70 Iranian students built a steel-framed house on the pattern of timber-framed buildings in the car park at Wuppertal University. After just two weeks, the topping-out ceremony took place. Since that time, the vision of a model timber-framed house in Isfahan has turned into almost dreamlike reality: Iranian and German professors and graduates set up a model construction company in Isfahan which has been building earthquake-resistant schools in Iran since 2008. These schools in villages and small towns are also an object lesson in how houses have to be built in order to make them earthquake-resistant. Once understood, the model company will then build all the houses needed by the young generations in Iran.

„A Fachwerkhaus in Isfahan – an unusual sight for Iranian eyes and an enormous challenge for Iranian construction engineers."

A Fachwerkhaus in Isfahan – an unusual sight for Iranian eyes. And an enormous challenge for Iranian construction engineers who still have to prepare the ground for this method of earthquake- resistant building in their country. Whereby, Iran is actually the ideal place for it. In Isfahan there are large steel-mills, and Iran has sufficient deposits of ore. The specialised steel works are to be produced by an industrial enterprise in Isfahan with German computer-operated machines. Human error in manufacturing will thus be excluded. Once the prefabricated steel construction has been erected, the infilling and finishing will be undertaken by local labour. This will create employment and make living more attractive, even in the villages. If this earthquake-resistant form of construction can achieve cultural acceptance in Iran, we might, in future, find lots of pretty Fachwerkhäuser lining the streets of the towns and villages beside the marble palaces.

Georg Pegels, Hamid Isfahany Georg Pegels, Hamid Isfahany

Dr. Hamid Isfahany is a Senior Lecturer at Brighton University in the United Kingdom. From 2005 to 2006, he was a Georg Forster Research Fellow at Wuppertal University, working with his academic host, Professor Dr.-Ing. Georg Pegels, who actively supports German-Iranian cooperative projects.

 

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