Coquitlam, B.C. shoring wall collapse. 8

[3DDave]

A fun shoring wall collapse.

https://bc.ctvnews.ca/jaw-dropping-video-shows-collapse-at-coquitlam-b-c-construction-site-1.6668311

Looks like the anchor team did a great job, the team who made the wall not such a great job, and whoever was in charge of deciding how many anchors to put in to go with that wall, a really terrible job.

It was slow enough in the early stages to get everyone away. So, expensive but not tragic. Except for the people managing the money. For them it's going to be rather painful. Also painful for commuters who used the street that no longer has dirt beneath it.

 

[LionelHutz]

The payment structure is not conducive to good journalism.

It's not conducive to most good how-to videos either. They've got to tell there life story up to the point of why they're doing what they're showing first to get the video length up.

 

[JAE]

phamENG - kudos to you and agree 100%.
So many of those online "experts" show up hoping to get views for their $$.

 

[phamENG]

LionelHutz - Touche. I've seen some pretty awful how-to's, too. It's usually enough to get me started on something, at least.

JAE - thank you.

 

[Lomarandil]

Sounds like we're nominating Pham to start a Youtube channel? All in favor...

 

[dik]

You forgot the emoji...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[spsalso]

At approximately 1:03 in this video:

https://www.youtube.com/watch?v=O1p75Tn2iJI

It appears that sand/soil is being dumped from the edge of the excavation, down into the hole, near the location of the blowout.

Is there a reason to do this? I would think they already have more than enough sand there, already.

And, to me, it surely looks like the soil is mostly sand. From the way it flows. But then I come from the land of clay.


spsalso

 

[3DDave]

Material is being dumped inside the excavation to provide support for the remaining wall at or above the rupture.

 

[MTNClimber]

It does look like sandy material for buttressing the wall. We’ve had to do this with crushed stone when a drunk driver hit a fire hydrant behind a 20’ tall soldier pile and lagging wall—nothing like getting that call at 2:30 AM.

I can’t say that’s a great spot to sit the excavator and stockpile, though. It appears to be within the influence of the wall, which would add lateral pressure to the system. Unless there’s a pile supported equipment pad right there.

 

[spsalso]

Thanks for the explanation. Gonna take a lot of sand. Of course, some's already been placed by the leak.

I noticed that the blowout happened pretty high on the wall. It seems the pressure on the wall would have been greater, farther down towards the bottom.



spsalso

 

[FacEngrPE]

seems the pressure on the wall would have been greater, farther down towards the bottom.

Exactly why piling up dirt on the toe of a wall or embankment helps, it partly balances the horizontal load resisted by the wall anchors. In this case hopefully providing the engineers some time to develop a robust repair.

I applied this approach to a hillside that was having slippage into a roadway. A geotech examined the situation, and recommended piling 3 feet of No 57 stone along the length of the toe of the hillside. Now 30 years later, the repair is still good.

 

[FacEngrPE]

First Video Retaining Wall Collapse in Canada Casey Jones - Dec 5 2023

This followup video by Casey Jones shows a good picture of the finished backfill stabilizing the collapse site.
Retaining Wall Collapse in Canada - Viewer Comments Casey Jones Dec 10 2023