Ancient architecture that defies earthquakes

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The powerful 7.8-magnitude earthquake that hit Turkey and Syria on February 6 killed nearly 50,000 people, most of whom died under the rubble.

The tragedy falls on a long history of massive death and destruction from recent earthquakes: the 1999 İzmit earthquake near Istanbul killed at least 17,000 people; The Gujarat earthquake in India in 2001 killed more than 20,000 people; The 2005 Kashmir earthquake in Pakistan killed more than 87,000 people and left about 3.5 million people homeless. The immediate cause of human tragedies was not the shaky earth itself, but the buildings in which the people were, most of which were constructed of reinforced concrete, a relatively quick and cheap method of construction.

Building on Tradition: A worker examines a wooden beam in a traditional Indian kath kuni building. These earthquake-resistant structures lack metal and mortar, which allows them to flex as needed during a tremor. Photo by Jay Thakkar.

Earthquakes don’t have to be so deadly, scientists who study the issue say. 1 Many traditional buildings have stood the test of time in areas that have endured high seismic activity for centuries.

In Japan, people have long built earthquake-resistant structures mostly out of wood. But a different tradition shows that even stone buildings can withstand intense shaking—if built with clever physics and architectural adaptations, honed over the centuries.

In India’s mountainous Himachal Pradesh region, near where the Indian plate collided with the Eurasian plate, many structures built in the Kath Kuni style have survived at least a century of earthquakes. In this traditional method of construction, the name, which translates as “wooden corner,” partly explains the method: the wood is layered with stone, resulting in improbably sturdy multi-storey buildings.

The gravitational force of the structure itself holds the stones in place.

It is one of the many ancient techniques tracing fault lines across Asia. The foundations of the timber-binding system of architecture were probably originally laid in Istanbul around the 5th century. The stone masonry and wooden beams can still be seen in Nepal as well as in the Kashmir tradition of Taq, Diwari Chicken and Pakistani Pattar. Even Türkiye has a long tradition of similar building methods. Despite its ancient origins, this form of construction has often been better for centuries than most contemporary buildings across the continent’s many seismically active regions.

The kath kuni buildings are built along the natural contours of the hills, and usually get their distinctive angles from the giant deodar cedar, which reaches 150 feet high and 9 feet wide across the Himalayas. These rafters are stacked between the dry stones, creating the walls. A single wooden “nail” joins the beams where they meet together.

Moveable feature: Many traditional architecture practices in some seismically active regions of Asia for centuries have relied on the moveable feature. Buildings in the kath kuni method of northern India (left) rely on gravity to help achieve stability, and a layered pattern of loose stones and rafters (right) gives the buildings flexibility that concrete lacks. Image source: (left) Photography by Jay Thakkar; (Right) Nagajyotsna/Wikimedia Commons.

As the heavy structures rose vertically, usually two to three stories, the heavy stone masonry contracted, giving way to more wood. A drop ceiling usually has shingles resting on wooden beams. says Jay Thakkar, a faculty member at the Center for Environmental Planning and Technology at the University of Ahmedabad, India, who is a co-author of Prathaa: Kath-kuni Architecture of Himachal Pradesh.

The buildings stand free of any mortar or metal, making them more capable of shifting and flexing with the torque in the ground. This brilliance of mobility continues even underground. They were built over a ditch at least a few feet deep filled with loose stone blocks that served as a flexible base. While a building constructed from what looks like rubble at first might seem like an odd defense against earthquake damage, it works. The gravitational force of the structure itself holds the stones in place.

“Unlike a cement brick wall, which becomes one solid block, dry stone masonry is flexible,” Thakkar says. “The interlocking joints allow external forces such as earthquake tremors to dissipate through the masonry and thus prevent cracks in the walls.” He adds, “The wooden pin at the corner joint of the beams also allows for movement. So when an earthquake hits, the structure sways and shakes but doesn’t collapse.”

Despite centuries of clear evidence of the safety of these traditional structures, more and more people have turned to reinforced concrete construction. By the early and mid-20th century, reinforced concrete was taking root across Asia and quickly gained popularity due to its significantly lower labor costs. As such, it has become the default method for a lot of new construction, including any government-funded buildings. But “for reinforced concrete construction, poor quality construction in these materials has often resulted in buildings that are more dangerous than the traditional unreinforced masonry buildings they replaced, despite the promises made for concrete buildings,” wrote a team of researchers studying Traditional timber and masonry. buildings in Türkiye 1

Indian architect Rahul Bhushan, who is working on reviving traditional building methods in the Himachal Pradesh region, says, “The kath kuni style of architecture, while still used in the construction of temples, has somewhat fallen out of favor with other structures due to the advent of reinforced concrete as a building material.” Therefore, the traditional experience gradually gave way.

Boshan Group, called NORTH, trains construction workers and masons in traditional methods. Their workshops spark a renewed interest in earthquake-resistant architecture rooted in these ancient technologies. He hopes that momentum will continue. “People are gradually showing interest towards kath kuni and other traditional constructions like dhajji dewari again.”

The onus is now on practicing architects and researchers to convince government agencies to support a traditional building system, which can help contain the devastation the next time an earthquake rocks the region, which, as geological plates continue to collide, is only a matter of time.

Shoma Abhiyanker is a freelance writer based in India. She writes about travel, culture, the environment and architecture. She’s on Twitter at @throbbingmind.

References

1. Gülkan, P. & Langenbach, R. Earthquake resistance of timber and home-built dwellings in Turkey. XIII World Congress of Earthquake Engineering (2004).

Feature image by Jay Thakkar

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