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 Waste in the water – New purification techniques for healthier aquatic ecosystems
24.07.2018 | Eberhard Karls Universität Tübingen

nachricht Plenty of habitat for bears in Europe
24.07.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

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: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Staying in Shape

16.08.2018 | Life Sciences

Diving robots find Antarctic seas exhale surprising amounts of carbon dioxide in winter

16.08.2018 | Earth Sciences

Protein droplets keep neurons at the ready and immune system in balance

16.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>