Potential civil & defence engineering
1 Smart road humps
smart road hump would discourage dangerously fast driving without
causing inconvenience for good drivers.
Reducing urban air pollution
SALi filled road humps would allow vehicles travelling over the humps at the recommended maximum speed to make progress without significantly changing speed.
2 Isolating structures from vibrations caused by traffic,
2.1 The isolator concept
Figure 1. illustrates the principle of
a SALi based structural bearing that has one degree
Correctly packaged SALi has visco-elastic properties, so any vibrations are damped.
There is no
restriction on the type of elastomeric capsule that can be used. For
example, they can be hollow rubber balls or solid rubber balls
coated with lead.
The matrix fluid can be liquid or a gel.
The cylinder shaped packages can be made from similar materials to heavy duty fire hoses.
Figure 2. The SALi based structural bearing was originally proposed to Ove Arup as a low cost solution to the wobbling Millennium Bridge problem. It was rejected because so little peer reviewed research on SALi Technology had been done.
2.2 A simplified SALi based structural bearing design.
Figure 3. For civil engineering applications the elastic cords can be replaced by a saddle and trough arrangement.
A structural bearing for protecting buildings or sensitive equipment
from ground vibrations. As a bonus, the vibrations of the structural
supports would absorb and redistribute some of the energy of surface
3 The Three Gorges Dam
The Problem, as outlined in New Scientist magazine, page 11, 2nd March 2002. "The world's biggest hydroelectric scheme, being built on the Yangtze River in southern China, could spark a geological disaster. .... Western hydrologists fear that landslips falling into the reservoir could create waves that could damage the dam. 'The consequences of failure at the dam would rank as one of the world's worst man-made disasters,' says Philip Williams, a California hydrologist.
A SALi based solution: The diagram below illustrates the principle behind our proposed solution.
Figure 6. Surge waves travelling towards the dam wall would compress the SALi filled bags providing two forms of protection: (1) The bags would absorb wave energy reducing the stresses on the dam wall, (2) The space behind the dam, created by compressing the bags, would provide a "hole" for the wave peaks to fall into, reducing the volume of water that sloshes over the dam wall.
NEUTRAL BUOYANCY SALI BAGS
Figure 7. The SALi bag which is just floating in this jar of water is filled with expanded polystyrene beads and a matrix fluid consisting of sand and Bentonite clay. This fluid provide viscous damping.
SALi based protective systems could be retro-fitted to reservoirs, without requiring modifications to the existing structure. The level of protection could be gradually increased over time, at modest cost, by adding SALi filled bags on an incremental basis.
Settlements close to the water line of large reservoirs could be protected by SALi based pontoons. These would double up as harbours or embankments for public use. At times of the year, when the risk of landslips is low, the pontoons could be strung out, to provide pontoon bridges, linking settlements on opposite banks of the reservoir. In order to allow the intermittent passage of marine traffic, the central sections of the pontoon bridges could include air bladders, which are deflated, so that the section temporarily sinks below the depth of the ships keels.
4 Defence applications
Unpublished research at Cranfield University Royal
Military College of Science indicates that packages of SALi have good
blast mitigation properties. The blast energy absorption mechanisms are
not known for certain, but are likely to be a combination of scattering
and latent heat absorption processes.
Figure 8. The test rig used for the Cranfield blast mitigation experiments. The target layer being tested in this case is expanded plastic foam.
Figure 9. A SALi target layer consisting of expanded polystyrene beads in a wallpaper paste matrix fluid. (Essentially the fluid was water, but wallpaper paste was used for ease of handling.) The polythene bag packaging remained intact after the test.
Here are some potential defence applications that emerged from the Cranfield work.
4.1 Blast mitigation blanket for suspect vehicles
Figure 10. A blast
4.2 Portable giant "LEGO" style blast protection for buildings
Figure 11. Water is injected on site. The hollow spheres may be interconnected and also inflated on site. This would allow collapsible "LEGO" blocks to be used. The external faces of the blocks can be painted to harmonise with neighbourhood.
4.3 Blast protection for the undersides of vehicles
4.4 Prefabricated blast protection buildings for war zones
[Courtney, W. A. Impact absorbent building structures, British Intellectual Property Office GB9805887.8 (1998).]
Figure 12. The structure provides blast protection and can be erected quickly.
Figure 13. Adding a pump to circulate the matrix water between the inner and outer layers provides enhanced temperature control.
Figure 14. The matrix water can be used in the manner of sprinklers to douse fires.
Figure 15. One option for cool climates is to drain off the water from the inner layer in winter, to provide improved thermal insulation.
6 Future Martian and lunar settlements
Fifteen years ago in 2000, the SALi based blast protection building aroused the interest of NASA as a potential ionising radiation proof building for use on the Moon or Mars if local ice could be found to provide the matrix water.
Bill's 1980's experiments had demonstrated that chippings of vesicular lava could act as elastomeric capsules in SALi formulations incorporating water as the matrix liquid. The pockets of air trapped inside the vesicles by surface tension shrunk under impact. On the Moon, oxygen (produced by electrolysis of water) or carbon dioxide (produced by burning waste materials in oxygen) would have to be added to the vesicular lava during construction.
Figure 16. In the 1980's a wide range of open capsule designs were investigated, ranging from vesicular lava to chopped up drinking straws and hollow plant stems.
Figure 17. The SALi formulation tested for inclusion in the NASA proposal.
Media coverage of the work
Figure 18. For a few short weeks after the publication of this article, the in-joke amongst colleagues at Manchester University was, "What Manchester does today, the rest of the solar system does tomorrow."
But the joke upset Bill's research supervisor because of its relative status implications. - The documentation for NASA funding was never submitted and Bill eventually abandoned his expensive patent.
[Courtney, W. A.
Impact absorbent building structures, British Intellectual Property Office
Bill complained in writing to the head of the Engineering Department about the financially damaging obstruction of his research, but his complaint was ignored.
7 State of development
Unfortunately all work on the above applications has come to a halt because of the unresolved PedSALi problems and other shenanigans at Manchester University UK.
Experiments at Cranfield University had demonstrated SALi's impressive blast protection properties.
This research evidence was available before the start of the Afghan and Second Iraq wars. Lives may have been saved and troops offered greater comfort in war zones if the petty academic problems at Manchester University had not intervened.