image: Artist's impression of the tsunami generator and wave flume. view more
Credit: HR Wallingford
For the first time, a team of experts is preparing to create tsunami in a controlled environment in order to study their effects on buildings and coastlines - ultimately paving the way for the design of new structures better able to withstand their impact. Ahead of today’s (Monday 2nd) Coastal Structures 2007 International Conference Dr Tiziana Rossetto, UCL Department of Civil & Environmental Engineering, unveiled plans to develop an innovative new tsunami generator capable of creating scaled-down versions of the devastating waves. The UCL team will be working with marine engineering specialists HR Wallingford (HRW) throughout the project.
“Tsunami are water waves generated by earthquakes, underwater landslides, volcanic eruptions or major debris slides,” said Dr Rossetto. “The waves travel across oceans with small vertical displacements and in open water you could easily bob over one without noticing. It’s when the waves approach the coastline, hit shallower water, slow down, and grow taller that you get the huge wall of water that people visualise when you mention a tsunami.
“The main gap in our knowledge is about what happens when the tsunami wave approaches the nearshore region and then runs inland. These flow processes cannot be simplified using mathematical models because of the complex interaction that takes place with beaches, sediment, coastal defences and then in and around buildings.
“It is possible for the whole process to be simulated with hydraulic models, but to get meaningful data the tsunami wave has to be accurately generated in the first place. Conventional wave generators haven’t been able to replicate tsunami because of the unusually long wavelength that is required.”
Professor William Allsop of HRW said: “Our new machine will control the flow of a large mass of water by using air suction within an inverted tank. We have used this technology over many years to make model tides in large scale models and our collaboration with UCL means we will be able to produce a unique research facility.”
The new tsunami generator will be able to create multiple waves, replicating the three or four peaks experienced during the Boxing Day tsunami that hit the Indian Ocean in 2004. The tsunami will pass down a 45m long flume at realistic wavelengths, mimicking the characteristics of waves which have passed from deep water (approx. 200m) into shallow water (20m – 50m) as they approach the coast. The wave flume will be equipped to measure coastal processes, inundation and wave forces as the tsunami travels up a shelving seabed, breeches the coastline and flows inland.
After the initial series of experiments, a team of researchers from UCL and HRW will go on to examine the effects of retreating and repeated waves on seawalls and beaches. The tests will measure the force exerted by the waves on representative buildings and quantify the wave’s ability to erode the coast, potentially destabilising structures completely.
The tsunami experiments will take place at HR Wallingford’s laboratories in Oxfordshire and construction of the generator is scheduled for completion in the summer of 2008. UCL and HRW plan to make the facility available to international teams of researchers in autumn 2009.
Notes for editors:
The ‘Coastal Structures 2007 International Conference’ is being held in Venice, Italy, from July 2-4. For further information see www.cst07.corila.it
Images:
A selection of hi-res artist’s impressions of the tsunami generator and wave flume can be obtained from the UCL Press Office (contact details above).
All images should be credited to HR Wallingford.
About UCL:
Founded in 1826, UCL was the first English university established after Oxford and Cambridge, the first to admit students regardless of race, class, religion or gender, and the first to provide systematic teaching of law, architecture and medicine. In the government’s most recent Research Assessment Exercise, 59 UCL departments achieved top ratings of 5* and 5, indicating research quality of international excellence.
UCL is the fourth-ranked UK university in the 2006 league table of the top 500 world universities produced by the Shanghai Jiao Tong University. UCL alumni include Mahatma Gandhi (Laws 1889, Indian political and spiritual leader); Jonathan Dimbleby (Philosophy 1969, writer and television presenter); Junichiro Koizumi (Economics 1969, Prime Minister of Japan); Lord Woolf (Laws 1954, Lord Chief Justice of England & Wales); Alexander Graham Bell (Phonetics 1860s, inventor of the telephone), and members of the band Coldplay.
About HR Wallingford:
HR Wallingford is an independent non-profit distributing company limited by guarantee that offers specialist services in civil and environmental engineering and hydraulics worldwide. HRW has an international reputation for scientific and engineering excellence with a thorough understanding of the water environment.
With a staff of approximately 200 including engineers, scientists, mathematicians, technicians and support staff, HRW covers the full range of problems encountered in hydraulic engineering where water flows with a free surface; in open channels, pipes and sewers, rivers and floodplains, estuaries, on the coast or offshore. A programme of strategic research underpins HRW’s technology base and ensures that its engineers and scientists remain at the forefront of knowledge in their specialist areas. HR Wallingford has established strong capabilities for physical and numerical modelling in all major fields of civil engineering hydraulics. HR Wallingford has some of the world’s most extensive facilities for physical modelling including:
- large experimental halls to accommodate physical hydraulic models
- workshops and specialist technicians who manufacture detailed model structures;
- specialist instrumentation and test devices
Based on a 36 hectare site near Oxford, UK, HR Wallingford has extensive international experience, with offices in the US, UAE, Malaysia and Italy and agents around the world.
HR Wallingford staff are experienced in providing effective and practical solutions to problems in the water environment. Long-term research ensures that HRW remain at the forefront of technology. Many staff are recognised international experts and have been closely involved in writing and developing key guidance. In relation to maritime structures, particular areas of expertise are important in deriving robust and reliable predictions:
- Detailed understanding of wave hydrodynamics, and of wave load analysis
- In-depth understanding of the capabilities of numerical modelling of waves and wave processes
- Concept design of specialist marine structures and breakwater studies;
- Coastal impact assessments and environmental modelling
- Wide understanding of design methods and responsibilities, of construction practice and techniques
HRW often form multi-disciplinary teams with other research organisations, universities or consultants to tackle unusual problems relating to management and use of water. For example the partnership in "Wallingford Water" covers the whole hydrological cycle from rainfall, through rivers, to the sea. VOWS, CLASH and PROVERBS projects have all advanced design methods for seawalls and breakwaters.
More information on HR Wallingford can be found at www.hrwallingford.co.uk