Sarwidi designs earthquake-resistant buildings
Sarwidi designs earthquake-resistant buildings
Sri Wahyuni, The Jakarta Post/Yogyakarta
In the wake of the apocalyptic tsunami that hit major parts of
Aceh and North Sumatra, people living in earthquake-prone areas
throughout the country must be wondering about the desirability
of earthquake-resistant homes.
Most parts of Indonesia are earthquake-prone.
However, poor anticipation and limited scientific efforts to
predict the arrival of earthquakes means that natural disasters
become fatal, especially large magnitude quakes.
"The quake itself is not lethal, but the ruins of a building
ripped off by the quake can kill people," said Sarwidi, who holds
a doctorate in civil engineering from the Yogyakarta-based
Indonesian Islamic University (UII), and who underlined the
urgency for people living in areas prone to earthquake to have
earthquake-resistant houses.
Encouraging people to construct buildings resistant to
earthquakes, according to Sarwidi, is not difficult, as science
and technology have made it possible to determine the zones as
well as the intensity of potential earthquakes around the globe.
"By encouraging people to build only earthquake-resistant
buildings in areas considered prone to earthquakes, we can
prevent such natural phenomenons from turning to disasters," said
Sarwidi, who is also director of the UII Center for Earthquake
Engineering, Dynamic Effects and Disaster Studies (CEEDEDS).
"Earthquakes may occur, but we can prevent them from
destroying our houses by making them resistant to earthquakes,"
he added.
Earthquake-resistant houses are relatively affordable.
Additional cost is only needed to make a more "elastic" or
ductile building.
"The keys to an earthquake-resistant building are 'not too
heavy or brittle'," he said.
CEEDEDS has conducted a series of observations in several
regions in the country that have been hard-hit by earthquakes,
and the studies have proved that the majority of damaged
buildings have not been appropriately constructed.
They are buildings that are traditionally designed, built by
local workers, using locally available materials, and are not
constructed under the supervision of a professional. They are the
kind of buildings that most Indonesian families occupy, even in
urban areas.
"Therefore it is urgent that information be disseminated to
improve people's knowledge about the concept or theory of a
building's resistance to earthquakes," he said.
For this purpose, CEEDEDS has issued a manual on how to build
simple, earthquake-resistant buildings, titled Manual Bangunan
Tahan Gempa untuk Rumah Tinggal Sederhana Tembokan (Earthquake-
resistant Building Manual for Simple Concrete Homes), that
anyone, especially mandor (traditional construction supervisors)
can use as a reference.
In many traditional buildings a mixture of bricks and cement
is used, instead of a concrete construction with reinforcing
steel structure inside as the foundation band that renders them
resistant to sway or quake.
The manual also suggests ensuing that walls, usually made of
either clay bricks or batako (concrete blocks), are made in the
right way by adding enough vertical and horizontal concrete
frames.
"Ideally, every three square meters of wall should be framed
with vertical and horizontal concrete supports. Reinforcing steel
bars, eight millimeters or 10 millimeters in diameter, are
sufficient for this purpose," Sarwidi explained.
No less important when constructing a house that purports to
be resistant to earthquake, according to the manual, is the
existence of a roof band.
Such construction in principle unites the structure of the
entire building, making a house more resistant to sway and quake.
Evidence supporting the CEEDEDS concept relates to an
earthquake that jolted the Central Java town of Banjarnegara: a
house on a riverbank was left intact while other houses in the
vicinity were shattered. The house was designed using CEEDEDS
concepts.
"I have made instruments, which I call Alat Goncang Gempa
(earthquake simulator), to prove that a house with such a
structure is resistant to earthquakes," Sarwidi said.
It is necessary to confirm the concept because Suwardi
strongly believes that many traditional houses are built without
considering safety and strength, which includes concrete
foundation bands, concrete frames for wall reinforcement and
concrete bands for the roof.
"My research has revealed that a house built using these
concepts can resist 11 consecutive quakes," he said.
Therefore, it is urgent that these building concepts be
disseminated to as many people as possible, especially those
living in areas prone to earthquake.
CEEDEDS has promoted the ideas to mandor in several
earthquake-prone regions.
"We welcome anyone who would like to know more about our
innovations for earthquake-resistant buildings," Sarwidi said.