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Chicago Tribune
February 17, 2001
December 27, 2000

TRADITIONAL BUILDING METHODS BEAT

CONCRETE IN QUAKE ZONES

By Catherine Collins


Randolph Langenbach picked up a rock and struck the concrete pillar
of the half-finished house in Kucuk Armutlu, one of the many
shantytowns that in recent years have taken root on almost every empty
hillside in this crowded city.

The pillar, stained by the rusting grime running through its center,
shattered on impact, and bits and pieces of concrete mixed with the
rubble below.

"Here you have a high-tech material, applied in a low-tech
situation. Reinforced concrete is not a material for Saturday
fixer-uppers," said Langenbach, a [former] University of California
architecture professor who was visiting Turkey to speak at the first
Earthquake Safe International Conference, sponsored by UNESCO,
Turkey's Ministry of Public Works, and the International Council on
Monuments and Sites.

In what might seem to fly in the face of conventional architectural
and engineering wisdom, the focus of this conference was apparent in
its small print: "Lessons to be learned from traditional buildings."
Specialists from 25 nations gathered to study not the ruins of
earthquakes, but the buildings that remained standing, especially
those built using "vernacular" or "traditional" methods.

"The message of those traditional buildings standing erect among the
ruins of Aug. 17 and Nov. 12 should be read clearly and correctly
evaluated," said Turkist architect Ortay Ekinci, discussing the
devastation of Turkey's most recent major earthquakes.

Seismically sound construction techniques are as old as civilization
itself. But today hundreds of millions of people living in densely
populated areas around the globe are at risk from earthquakes, said
David Michelmore of the International Council on Monuments and Sites.

"Social and economic changes and increasing globalization has resulted
in the abandonment of traditional building techniques and their
replacement, in most parts of the world, by concrete pillar
construction.

"Yet this loss of tradition can have not only a negative effect on the
environment but, in earthquake areas, can lead to human tragedy,"
Michelmore said.

One after another, the experts expressed concern that from Istanbul to
Mexico City, Nepal to Manila, China to Japan, the inability of
reinforced concrete to withstand a major earthquake when it is used
incorrectly and with substandard building practices could lead to an
unprecedented disaster.

They fear a disaster surpassing that of the August 1999 7.4 Marmara
earthquake that struck northwestern Turkey, killing more than 18,000
people and injuring nearly 50,000.

Reinforced concrete has become the preferred building material in most
of the world outside of North America. It is inexpensive and fast. In
cities such as Istanbul, older buildings have been torn down and
replaced by concrete structures. These structures are in downtown
business districts, line the highways as midrise apartment buildings
and have popped up in impoverished settlement areas, like Kucuk
Armutlu.

If used correctly and under the best conditions, concrete structures,
reinforced with steel bars, can withstand earthquakes. The problem is
that the methods and raw materials often are not ideal. And once a
building is up, the quality of the concrete is nearly impossible to
judge.

Timber construction, similar to Turkey's himis or timber with stone
construction, can be found throughout Europe and Asia. Unlike
inflexible concrete structures, timber buildings have the ability to
move with an earthquake and absorb its force throughout the entire
structure. Many of these traditional structures stood amid the rubble
of the last earthquakes.

During the conference, Turkish architects Demet Gulhan and Inci
Ozyoruk Guney presented the first hard evidence that people living in
modern, reinforced concrete structures died at a much higher rate than
people living in older, traditional houses during the Marmara
earthquake.

In one example from their study, the Sehitler district of Golcuk had a
roughly equal number of reinforced concrete and traditional
structures. Yet of the 290 deaths, 287 occurred in reinforced concrete
structures and only three occurred in traditional-style buildings. Of
the 789 traditional buildings, 701 survived the quake undamaged, but
of the 814 reinforced concrete buildings, only 550 escaped damage.

Of the buildings that collapsed, only four were traditional buildings,
while 60 were made of reinforced concrete.

"Reinforced concrete frame structures presented a high level of damage
due to low-quality concrete, inadequate engineering, incorrect
construction techniques, poor detailing, inadequate inspection or
observation of construction, and lax attitudes of
authorities in the application of the building code
," Gulhan said
during her presentation.

Most of Turkey is considered vulnerable to earthquakes. Yet according
to Turgut Cansever, one of the conference speakers, "approximately 70
percent of the building stock of Istanbul was built without technical
assistance."

Depending on the region, much of the building stock is illegal, built
without professional planning or supervision, like the houses found in
communities similar to Kucuk Armutlu.

In the years following World War II, thousands of people flooded
Turkey's major cities and after finding a dearth of housing, the rural
migrants invaded state-owned land and put up their own houses. Those
illegal buildings became known as gece kondus, which roughly
translates to "landed overnight."

Although Langenbach was reluctant to make predictions about Kucuk
Armutlu's gece kondus in another earthquake, he said, "There's an
irony that in this place where people add to their homes a bit at a
time when they have the money, they are better off in smaller, lower
buildings."

Turkish architect Hayim Beraha, who was touring the settlement with
Langenbach, was more direct. "This will collapse," he said. "These
people are from the countryside. And where they came from, they used
to know better. The problem is the perception that living in a modern
house is living in a concrete house
."

"Tradition only survives where concrete trucks; cannot
reach
," Michelmore had said during the conference.

A few steps down the hillside was a relic of tradition--a small himis
house with a timber frame, in which rubble had been stuffed and held
in place with mud mortar.

The entire exterior surface had shed its stucco, but that was evidence
of the building's soundness because it demonstrated that the stress
caused by an earthquake was spread evenly.

A cow thrust his head through the himis structure's window. "Look, a
cow living in the safest building in Kucuk Armutlu," said Langenbach.
"I wish these gece kondu builders had stopped to study this building first,
before constructing their own."

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