Earthquakes and fish tanks....

[Anonymous]

So I'm putting together a couple large acrylic tanks for a new restaurant. The architect is telling the owner that all sorts of seismic bracing needs to be put under the tanks, and that a lip needs to be put around the bottom of it so that it doesn't slide off the stand. I told the owner that this is complete hogwash, and that any earthquake strong enough to shake the tank off the stand will likely destroy the entire building--the tank will be the least of his worries. FWIW, these are both relatively low profile, large footprint tanks. One is a 150 tall IIRC, 5' x 2' x 30" tall. The other is a 300 tall, something like 8' x 2' x 30" tall. Am I in the right here?

 

[Anonymous]

I think you're probably right. Sounds like someone's trying to tack on some additional construction costs. Like you said, if a 300g is sliding around, your roof probably is too. Besides, I'm sure your client's (Kev?) insurance would cover any damage that resulted from earthquake damage. At least it should... A hearty stand might be advisable though, since that's probably more likely to give way in an quake, rather than the tank sliding/tipping.

Man, I miss worrying about quakes in California; instead of these damn hurricanes on the east coast... :?

 

[Fatal Morgana]

30 inch tall tank is not low profile, but rather regular profile consider the other dimensions of the tank. There is two school of thought on this issue.

1, if the earthquake is stong enough to move the tank off a little on the stand, it would be impossible to move it back on without draining most of the water, and overtime, it break the tank.

2, if the quake is strong enough to move the tank, it will bring the stand and bracing with it. Without the bracing, the tank may break, but with the bracing, the tank bring the wall down with it.

Most of the time when people describes what happened in an earthquake is that the water in the tank will splash all over the place. Sort of like a nice wavemaker. Some said that the splash caused half of the water to land on the floor, along with fishes. Tank usually failed when rock tumbled down, and hit the bottom, or the side, and cause a shock that combine with the wave, break the tank. The fluidity of water in the tank let it give a little, so it usually does not move as much as other object with similar weight and dimension. Other factor is the direction of the shaking, etc.

I would suggest you look into seim. simulation with fluid.

 

[Anonymous]

My money is on the advice of the architect. If the tank moves at all....you will be in for some real problems.

 

[Anonymous]

There's no way the tank is breaking from a rock hitting the bottom. It's an acrylic tank.

CK,
As you probably know most earthquakes in CA would impose a shear/slide type wave on the tank; I don't see how that's going to do much damage beyond sloshing some water out.

 

[Anonymous]

Uh uh, after having been through the Whittier Narrows quake I can tell you that it's entirely possible to have GODZILLA grab your home, building, whatever, and POUND IT ON THE GROUND TIL EVERYTHING COMES APART!!! 8O

I am completely serious about this.

Also, having set up a couple of rather large tanks myself (around 1,500gals) under the watchful eye of a very old old-timer (40+ years in the biz, in SoCal) I know that what you and I think can't be moved by any but the biggest quake can easily be moved by a relatively small temblor. Go at least with the lip, and honestly, go with Fatal's advice and let the architect make the call on this stuff. You do NOT want the headaches possible.

 

[ricky1414]

I agre with SM. Even minor quakes can do major damage.
Always look into the prospect of CYOA. Let the architect deal with the problems should anything happen. That why they are bonded/insured. Any consultation/advice rendered on a professional basis leading to some sort of constructive failure can have some serious ramifications, especially if you do not carry liability ins.

 

[Anonymous]

Matt, we had to go thru the same thing when installing a 650g in a restaurant. I'd go with what they say, it'll help you in case of a lawsuit. We had a structural engineer sign off on ours. What an ordeal. Talk about a nailing scheme.

 

[holry7778]

As an Inter-Arch. I have to say that if it tople a building a little fish tank is nothing. Having the lip and other things are simply safety measure to try to keep things where they are and to keep 100's of $$$ for hitting the floor in pieces. My advice is obviously stick with the Architect. If it break then He's possibly liable and not you.

 

[Anonymous]

I'd go with what they say, it'll help you in case of a lawsuit. We had a structural engineer sign off on ours. What an ordeal. Talk about a nailing scheme.

Yep! You don't want to get in a legal battle with a Clownfish.

 

[comatose]

i've seen a video of a tank in japan where the tank and stand was on extra heavy duty wheels, there was a very strong quake, the tank slide back and forth and never spilled a drop.

 

[Fatal Morgana]

>... the tank slide back and forth and never spilled a drop.

Only if the direction of the rocking is accomdated by the wheel. A 5000 pound of water sliding toward you at 1 mph can do a lot of damage to your chest...

 

[Anonymous]

Maybe you should have airbags installed.

 

[Fatal Morgana]

No use, bangbang. Air bag is only useful if it is a person's head (max. at 20 lb.), not something is that 250X heavier.

 

[Anonymous]

On one hand I see where Matt is coming from here, simply because I had a large tank set up during the big 7.2 quake, and it didn't move an inch. Anything large enough to move a tank off the stand, and your damn tank is the least of your worries.
On the other hand, why deal with the mess?
The architect is asking to assume the liability here, I say give it to him and do what he says.

Jim

 

[Anonymous]

I'm going to let him do his thing. It's not my money. It just bugs, because he calls me everyday seemingly with a new question--how thick is the acrylic? How much does the tank itself weigh? (why would this even matter? He didn't even want to know the weight of the water and rock, then calls me back the next day for that very info :roll: )

Then I have to call the nice, patient folks at Aquaplex and ask them...the guy said he had never been asked the weight of a dry tank before

 

[holry7778]

Sounds like he has no clue what he is doing so he doing what archs do best cover their buttsand over design

 

[Mihai]

It's not overdesign. It's common sense. Think that a quake moves huge buldings and pieces of earth, you think it will not move your tank? That's because you think is "heavy". Heavy for you to move, but not for a quake. I had a 100gal move by 20" by a quake back home (and half of the water on the floor).

Go with the bracing, you'll not regret it.
M.

 

[Anonymous]

During the 89 Quake in the SF Bay Area, we had a 100 Gallon Freshwater Tank (I was a little kid at the time living with my parents).

All I remember is that after the quake we had no more fish tank and all the fish dried up.

Yup, the tank fell..

 

[Anonymous]

Yikes. Interesting, and mine didn't move an inch. Just depends on what building you're in I guess. :?

Jim