Cinderblock stands and earthquakes?

[Ryo Watanabe]

Hi everyone, I was wondering if cinder block stands like the ones below are able to handle earthquakes? Or would it depend on the strength of the quake??

Does anyone have experience with this?

 

[Cory]

Clearly you haven't watched my cinder block stand video with an earthquake rant. 

 

[Ryo Watanabe]

1 hour ago, Cory said:

Clearly you haven't watched my cinder block stand video with an earthquake rant. 

 

Thank you Cory! I swear I’ve watched this video in the past!! But not the earthquake rant towards the end 😅
thank you so much, just finished watching it 🙂

[Mr. Ed's Aquatics]

I've always equated them with the building codes that require cinder block walls in areas where earthquakes and hurricanes are problems. If structures are more likely to survive earthquakes and hurricanes built with cinder blocks over lumber, you'll likely do better with your tank stands as well. 

Hopefully you never need to find out. 

[Ryo Watanabe]

2 hours ago, Mr. Ed's Aquatics said:

I've always equated them with the building codes that require cinder block walls in areas where earthquakes and hurricanes are problems. If structures are more likely to survive earthquakes and hurricanes built with cinder blocks over lumber, you'll likely do better with your tank stands as well. 

Hopefully you never need to find out. 

Thank you very much 😊

[Errk25]

Zenzo at Tazawa Tanks has them an he’s in San Francisco which is earthquake country. So I figure they would be as good as anything else. Big enough earthquake will bring anything down though. 

Edited August 30, 2020 by Errk25

[TheDukeAnumber1]

I generally agree with Cory's rant, but I do believe that you could probably get a significant increase in seismic resistance on the cheap with some well placed metal strap bracing.

If you want to get nerdy for a second and see what your seismic risk is according to typical US building codes see below.

Go here -> https://hazards.atcouncil.org/#/  (note this will only work for US locations)

1) Select seismic, enter the location and hit enter.

2) Select ASCE 7-10, Risk Category I, Site Class D

3) See additional information and check what your SDC letter is and use the table below to see what seismic risk you are in.

 

@Mr. Ed's Aquatics

Cinder block walls in those regions will be reinforced with rebar and grouted. Since these shelves are just stacked blocks they offer no real advantage over a similarily sized adequate wood shelf and in all likelyhood are less resistent to earthquakes since wooden shelves are typically fastened together.

Edited August 30, 2020 by TheDukeAnumber1
spelling mostly

[Mr. Ed's Aquatics]

Yes permanent structures are made with reinforced, but they are required for their ability to shift and flex instead of collapsing. When I lived in San Diego, the only tank I lost during a quake was the one I had on a hugely reinforced wooden stand attached to the wall. With no way to wiggle, shift, flex, whatever you want to call it.... the entire bottom panel shattered and the stand basically broke in half.

The cinder blocks on the other hand barely moved, never lost any tanks and came through just fine. With everyone who actually does this having good success and no real horror stories about losing 30 tanks during a quake... I stand behind what I said. You're likely going to be just fine. Any quakes that can take down that kind of stand would also likely destroy wooden ones as well. 

[TheDukeAnumber1]

I'm just going to be straight with you Ed, what you said was wrong. Specific jurisdictions may require reinforced CMU construction over wood framed for specific structures but that in no way translates to just stacked cinder blocks for a shelf. It's not even in the ballpark. And when it comes to a structures ability to "shift and flex" instead of collapsing, wood building construction performs much better than reinforced masonry. (pulling that info from the code)

I'm glad the cinder block shelves have worked for you and sorry the wood did not, and I'm not telling you that building shelves that way is unsafe or doesn't have advantages...yet (maybe I'll eventually take the time to run the calcs), but anecdotal evidence is just that, anecdotal. And when it comes to earthquake resistance, it's the connection detailing that really makes the difference.

[Mr. Ed's Aquatics]

1 hour ago, TheDukeAnumber1 said:

I'm just going to be straight with you Ed, what you said was wrong. Specific jurisdictions may require reinforced CMU construction over wood framed for specific structures but that in no way translates to just stacked cinder blocks for a shelf. It's not even in the ballpark. And when it comes to a structures ability to "shift and flex" instead of collapsing, wood building construction performs much better than reinforced masonry. (pulling that info from the code)

I'm glad the cinder block shelves have worked for you and sorry the wood did not, and I'm not telling you that building shelves that way is unsafe or doesn't have advantages...yet (maybe I'll eventually take the time to run the calcs), but anecdotal evidence is just that, anecdotal. And when it comes to earthquake resistance, it's the connection detailing that really makes the difference.

I'll be just as straight with you, I disagree with what you are saying. I've both lived in quake zones and worked construction. And worked on repairing damage caused by quakes. And from what everyone I interacted with said and my own experience, the main benefit of cinder block exterior walls was that they would more often than not ...shift, crack, move, whatever where rigid construction tended to collapse. I believe this is also why the codes only require reinforcement in specific areas. The whole thing isn't reinforced by rebar and cement, much is just mortar. And that's how they shift instead of collapse, same as the stands...

When a quake struck my area and I didn't lose tanks on cinder block stands, they did the same thing as construction walls. Some blocks moved, maybe even cracked, but the structure as a whole stayed up.  Its like you think that not adding rebar negates the effects of gravity, friction and enormous down force. Build one and try to push it over, or take out the bottom brick. I don't know why you don't think that the same beneficial effects would translate but since I witnessed it I am going with my eyes over your opinion. 

Also if the codes were only for strength, they would require steel beam construction which is even stronger. But its rigid, and would be like traditional construction and be more likely to collapse.  Much like my 150 on a steel stand is more likely to tip over during a quake due to its high center of gravity and inflexibility. 

Adults are free to disagree, you think I'm wrong. Okay great, don't listen to me or my advice. I think you're wrong, and I will follow my own advice and just not follow yours.

Edited August 30, 2020 by Mr. Ed's Aquatics

[TheDukeAnumber1]

39 minutes ago, Mr. Ed's Aquatics said:

I'll be just as straight with you, I disagree with what you are saying. I've both lived in quake zones and worked construction. And worked on repairing damage caused by quakes. And from what everyone I interacted with said and my own experience, the main benefit of cinder block exterior walls was that they would more often than not ...shift, crack, move, whatever where rigid construction tended to collapse. 

When a quake struck my area and I didn't lose tanks on cinder block stands, they did the same thing as construction walls. Some blocks moved, maybe even cracked, but the structure as a whole stayed up.  Its like you think that not adding rebar negates the effects of gravity, friction and enormous down force. Build one and try to push it over, or take out the bottom brick. I don't know why you don't think that the same beneficial effects would translate but since I witnessed it I am going with my eyes over your opinion. 

Also if the codes were only for strength, they would require steel beam construction which is even stronger. But its rigid, and would be like traditional construction and be more likely to collapse.  Much like my 150 on a steel stand is more likely to tip over during a quake due to its high center of gravity and inflexibility. 

Adults are free to disagree, you think I'm wrong. Okay great, don't listen to me or my advice. I think you're wrong, and I will follow my own advice and just not follow yours.

And structural engineering is my profession, this isn't my opinion, this is data from the codes and design guides used to design these structures. I did not say the codes were only for strength and you definitely have some misconceptions about rigid strutures.

"Enourmous down force" will be beneficial for resisting wind loads but it does nothing to help you against earthquake loads. The greater the weight of the structure the greater the earthquake load it carries. Also, again, I'm not telling you not to use CMU blocks, I'm just saying that CMU doesn't have some special structural property that makes it better for stack block shelves in earthquakes. When reinforced masonry walls are designed, believe it or not, it's the steel that's designed to yield and absorb the seismic energy.

Also we don't disagree about using cinder block shelves, I already agreed they will probably be fine in most cases. We can't have a conversation if you read in disagreement where there isn't.

Edited August 30, 2020 by TheDukeAnumber1