Good Thinking

Seaside canopy could tilt to block storm waves

Seaside canopy could tilt to b...
In fair weather, the system's hypar shells would face upwards
In fair weather, the system's hypar shells would face upwards
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During storms, the shells would be angled toward the ocean
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During storms, the shells would be angled toward the ocean
In fair weather, the system's hypar shells would face upwards
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In fair weather, the system's hypar shells would face upwards

Although seawalls certainly do protect coastal communities from storm surge waves, those walls can be unsightly, plus they restrict access to the water. A proposed new system gets around those problems, by doubling as a canopy when not serving storm duty.

The concept is being developed by Prof. Maria Garlock, Assoc. Prof. Branko Glišić and PhD student Shengzhe Wang, all of Princeton University.

As long as the weather wasn't stormy, the system would take the form of a series of giant square "umbrellas," protecting people from the sun and rain as they walk along the shoreline.

Each unit's top section would measure about 8 meters (26 ft) per side, and be made up of a reinforced concrete shell about 4 inches thick (102 mm). That shell would have a high-strength saddle-like shape known as a hyperbolic paraboloid, or a hypar for short.

Supporting the horizontal shell would be a set of vertical columns, measuring 10 feet tall by 20 square inches thick (3 m by 129 sq cm). Those columns would be attached to the underside of the shell via motorized hinges.

During storms, the shells would be angled toward the ocean
During storms, the shells would be angled toward the ocean

When a storm was approaching, the shell would tilt relative to the columns, so it would be facing out to the sea instead of up to sky. It could then block incoming waves, using its hypar shape to deflect the wave energy and redirect the water back outward. Based on computer models, it is estimated that the shells should remain stable even when receiving a wall of water approximately 75 percent of their 8-meter height.

And as an added benefit, the shells could be used to collect rainwater and solar power when in their upright orientation. Wang has now built a physical miniature model of the system, with umbrellas measuring about 6 inches across (152 mm), which will be tested in a 10-ft (3-m) water channel.

The research is described in a paper that was recently published in the Journal of Structural Engineering.

Source: Princeton University

13 comments
paul314
If such thin columns and shells can in fact resist being tossed around by incoming storm waves, that would be wonderful. 20 square inches is a 4x5-inch or (10x13cm) column. Deflecting 30-plus tons of water with such a structure will be quite a feat.
Miner Bob
To add strength to the columns they should be tapered wider at the base and there should be a lip on the lower wall edge that dovetails into a reinforced curbing to keep the wall from being pushed upward.
WONKY KLERKY
I concur with Commentator 1 and add a raking brace to landward side of each column
(AofD of rake of brace TBD for passage of pedestrians under).
+
Just how would tilted PV panels stand up to being slammed by storm waves?
+
Don't want to be too finite and dtl the dwg, but . . . ......
Whether/not it is intended to save the captured rainwater -
Some drainage holes for rainwater would be nice.
if intended to discard the collected aq then they connected to the street path drains
or draining onto beach lower than path/road level
[don't forget your flap valves to beach side outlet of drains to stop the naughty sea surging up at high tide + similar further / ball valves (any&all serviceable please) to within the discharge pipes] . . . ......
before the bloody canopy trough fills up.
AladdinConnolly
Great idea. I doubt the current engineering analysis has been anywhere near robust enough to consider those dimensions valid. One reason I distrust the professionalism of the researchers is the suggestion these could be used for solar power collection. Considering the idea is to have waves beat them during storms, it would be a complete waste to have solar cells getting destroyed every single storm.
f8lee
@paul314 - I think the columns will be 20x20 inches, thus the "20 inches square" - though even that might not be strong enough for something big. But more concerning to my mind would be the requirement that there is 100% reliability on every one of the individual "umbrellas" - after all, if there are, say 50 of the devices along a stretch of beach and one fails, it will not be pretty...
aki009
That looks great. But like others have already noted, unless someone is intending to use Vibranium, those pillars will snap with the first good wave.
Vincent Bevort
You are all talking about the force of the waves and I totally agree with you. But how about the wind?
Just think about the force of a wind force of 10 Beaufort against these 8x8 meter panels. They will just simply sail away.
And the hinge on the columns cannot bear that much weight of the panels.
On a scale from 1 0 to 10 where 0 is bad: Idea 10 execution 0
buzzclick
Salt water and freezing temps aren't nice to concrete, so this would be best in temperate zones. The artist's rendering fails on many levels. There are too many unknown variables from a powerful Mother Nature to just simply effect a solution. Build (pile up) a breakwater away from the shoreline that has the ability to arrest the wave energies by using weight. This is the cheapest and most effective solution.
Brian M
Seems a good idea however sea defences need to be as robust as they can be for the given amount of money available, this seems to be too much of a compromise.

' could be used to collect rainwater and solar power when in their upright orientation'

That seems to be expecting a lot for solar power collectors even the toughest around today!

Douglas Rogers
I don't see any actuators. It looks like it is free to flop!