Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Post-tsunami Thailand yields lessons for coastal construction

25.02.2005


Engineering experts see how buildings and materials fared against walls of water



An inspection of Thai villages and ports struck by tsunami waves has uncovered some engineering lessons that might reduce casualties and destruction in future oceanic upheavals, a Johns Hopkins researcher said.

Robert A. Dalrymple, an internationally recognized expert on water waves and coastal engineering, was part of a nine-member team that recently toured southern Thailand, examining landscape and structural damage in areas that had been battered by waves up to 10 meters (more than 30 feet) high. The research trip to Thailand, along with similar expeditions to Sri Lanka and India, was organized and funded by the American Society of Civil Engineers, in cooperation with the Institution of Civil Engineers.


An earthquake in the Indian Ocean triggered the Dec. 26 tsunami, which killed more than 200,000 people in 11 nations and caused immense property damage. "The force of the fast-moving waves on structures was tremendous," said Dalrymple, who is the Willard and Lillian Hackerman Professor of Civil Engineering at Johns Hopkins. "We wanted to see which buildings and other structures held up against the waves–and which didn’t."

The American Society of Civil Engineers is preparing a detailed technical report. But Dalrymple said team and personal observations in post-tsunami Thailand led him to compile a list of general lessons for builders in coastal areas where future tsunamis may occur:

Elevated structures survive better.

The waves were powerful enough to smash through a building’s ocean-facing wall and break out the opposite side, and high enough to inundate a second-story level. Elevated buildings that allowed the moving water to pass through the lower level with little interference fared better than those with solid first-floor walls. Taller buildings that allowed people to reach heights above the wave’s crest helped reduce casualties.

Materials matter.

Reinforced concrete structures were more likely to survive the wave forces. In general, masonry (brick) and wooden structures did not fare as well.

Orientation is important.

Walls facing the ocean, allowing perpendicular impact from the waves, sustained more damage. Walls oriented in the direction of the flow sustained less.

Strong foundations are necessary.

In addition, landscaping or other features can protect the foundations against scouring, which is soil erosion caused by the moving water. Seawalls can be a very effective way to reduce wave damage. The structures must be continuous, however, with no gaps for pedestrian crossings. Also, such structures should not slope inland, allowing waves to slide up and over the walls like a skier.

Debris in the flow is hazardous. Many tsunami victims were injured or killed by debris pushed along by the powerful waves. Debris can be minimized if vehicles are parked and heavy items stored on the inland side of buildings. Ports are particularly vulnerable to tsunami waves. Boats and piers in a harbor hit by a tsunami have little protection.

Beaches in Thailand recover rapidly. The ASCE researchers discovered that within weeks of the disaster, natural ocean forces had returned the sandy beaches nearly to their pre-tsunami condition. The beaches have reopened, Dalrymple said, and Thais are encouraging tourists to return.

Dalrymple said several questions raised during the trip require further research. These include why the height of the tsunami varied dramatically along the coast of Thailand and how engineers can construct a mathematical model of wave forces as they pass through coastal structures.

Color Image of Robert Dalrymple available; contact Phil Sneiderman.

Related Links: Robert A. Dalrymple’s Web Site: http://www.ce.jhu.edu/dalrymple/dalrymple.html
Johns Hopkins Department of Civil Engineering: http://www.ce.jhu.edu
American Society of Civil Engineers: http://www.asce.org

Phil Sneiderman | EurekAlert!
Further information:
http://www.jhu.edu

More articles from Ecology, The Environment and Conservation:

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>