Vancouver House (1400 Howe St) | 151.5m | 52Fl | Completed - Page 44

Klazu · #**861** Posted **Apr 8, 2016, 10:40 PM**

Quote:

Originally Posted by officedweller

I'm still wondering what's behind the corner bench:

Original pic by McMinsen

Maybe they had to leave it to keep the two walls standing? Interesting that they had to use those huge beams at the south end of the pit, but nothing was required on the north side. What is the difference load wise?

osirisboy · #**862** Posted **Apr 8, 2016, 10:45 PM**

Quote:

Originally Posted by Klazu

Maybe they had to leave it to keep the two walls standing? Interesting that they had to use those huge beams at the south end of the pit, but nothing was required on the north side. What is the difference load wise?

No. And those beams used on the south side was because they couldnt drill into that wall (since it's a different property is my guess). All the other walls are supported with underpinnings

Regina14 · #**863** Posted **Apr 8, 2016, 10:54 PM**

The force from the ocean is the reason that wall was braced like that.

osirisboy · #**864** Posted **Apr 8, 2016, 11:28 PM**

I know you're pretty knowledgable but Are you sure? It's the same set up as trump had on its western wall. When it's to hold back force from the water they usually have a set up like what the Erickson had

mcminsen · #**865** Posted **Apr 9, 2016, 4:27 AM**

April 8 '16, my pics

Marshal · #**866** Posted **Apr 9, 2016, 8:18 AM**

I have no firm answers about these two things. Regardless, excavations can be very complicated to engineer.

There is no way water pressure could be the reason for the corner supports. There is no water table affecting this site and sea level is too low to impact the ground that high up the excavation.

What should be considered is the nature of the material the pit was dug into. It is possible that the north end has a stable geology like most of downtown, while the south end is a complex of sediments, moved material and man placed fill, all related to the changes to the shoreline over time. If the material at the south end lacks sufficient structure it's possible that underpinning proved too difficult, or too expensive, or simply not possible.

It is common practice to drill anchors under neighbouring properties with legal agreement, insurance and compensation.

Regardless, those supports are holding up the excavation wall (the material on the other side of the property line) not the ocean. That configuration lacks any form of coffer dam (like the Erickson) so it is not holding back any form of liquid pressure.

As for the chamfered bit in the northwest corner . . . no clue. I agree that it seems a bit deep for services. The only thing that deep would be the downtown saltwater emergency fire main (supermain) system (associated with the blue hydrants), but I don't think that runs near this site. So, ??? Maybe it just works with the parking/ramps design.

Regina14 · #**867** Posted **Apr 9, 2016, 12:17 PM**

Quote:

Originally Posted by osirisboy

I know you're pretty knowledgable but Are you sure? It's the same set up as trump had on its western wall. When it's to hold back force from the water they usually have a set up like what the Erickson had

That's what the engineer told me last time I was on site.

mcminsen · #**868** Posted **Apr 10, 2016, 4:15 AM**

Here are some pics from about 4:30 PM today.

April 9 '16, my pics

Regina14 · #**869** Posted **Apr 10, 2016, 4:24 AM**

Those pictures are amazing! Thanks!

officedweller · #**870** Posted **Apr 10, 2016, 6:43 AM**

Great shots!

giallo · #**871** Posted **Apr 10, 2016, 8:30 AM**

Great photos and great timing!

mcminsen · #**872** Posted **Apr 11, 2016, 3:11 AM**

No crane completion today but it looks like they've got the boom assembled.

April 10 '16, my pics

Vin · #**873** Posted **Apr 11, 2016, 4:42 PM**

Quote:

Originally Posted by Marshal

I have no firm answers about these two things. Regardless, excavations can be very complicated to engineer.

There is no way water pressure could be the reason for the corner supports. There is no water table affecting this site and sea level is too low to impact the ground that high up the excavation.

What should be considered is the nature of the material the pit was dug into. It is possible that the north end has a stable geology like most of downtown, while the south end is a complex of sediments, moved material and man placed fill, all related to the changes to the shoreline over time. If the material at the south end lacks sufficient structure it's possible that underpinning proved too difficult, or too expensive, or simply not possible.

It is common practice to drill anchors under neighbouring properties with legal agreement, insurance and compensation.

Regardless, those supports are holding up the excavation wall (the material on the other side of the property line) not the ocean. That configuration lacks any form of coffer dam (like the Erickson) so it is not holding back any form of liquid pressure.

The Exchange had similar bracing during excavation as well, and only on one side. So does that also mean soil conditions there, or other ground pressures like those from buildings nearby? I know that area is too high and far away to have any sea level pressure, plus it's on the wrong side.

Quote:

Originally Posted by mcminsen

June 7 '15, my pics

Vin · #**874** Posted **Apr 11, 2016, 4:47 PM**

Thanks for the updates mcminsen! Would be great to see one of the triangular commercial buildings in this project under construction concurrently. 3 cranes in that neighbourhood would look wonderful.

mcminsen · #**875** Posted **Apr 12, 2016, 3:55 AM**

April 11 '16, my pics

Marshal · #**876** Posted **Apr 12, 2016, 4:56 AM**

Quote:

Originally Posted by Vin

The Exchange had similar bracing during excavation as well, and only on one side. So does that also mean soil conditions there, or other ground pressures like those from buildings nearby? I know that area is too high and far away to have any sea level pressure, plus it's on the wrong side.

Yes, I remember those. I would not presume that they were used for that reason, but its possible. If conditions were not good there (for underpinning) it is likely the problem soils were different from those at Vancouver House (just based on location). These braces are used all over the world to solve many different problems . . . though its safe to assume they are used to hold material back, and so the material must be structurally 'mobile' on its own.

As for the 'pressures' of neighbouring buildings, remember that for soils, not bedrock, their loads only come into effect beneath their structural foundations. For example, for a point load, the weight is transferred to the soil beneath the footing, and through the soil (assuming it is monolithic) in the shape of a loading cone (this is akin of the cone shape you get when sand piles up in an hourglass). Neighbouring buildings do affect things, but often not as much as you might think.

AND, the photos continue to be first rate and very much appreciated. Thanks guys.

mcminsen · #**877** Posted **Apr 23, 2016, 7:37 AM**

April 22 '16, my pics

Otis_Van · #**878** Posted **Apr 24, 2016, 2:17 AM**

I noticed earlier today when I walked by that they seemed to be breaking up a section of concrete near the centre of the core.

Just went back and compared McMinsen's photo from a week ago with one from today, and it looks like they took out one of the big support columns.

Would be curious to know the story.

Before:

After:

mcminsen · #**879** Posted **Apr 24, 2016, 2:56 AM**

Quote:

Originally Posted by Otis_Van

I noticed earlier today when I walked by that they seemed to be breaking up a section of concrete near the centre of the core.

Just went back and compared McMinsen's photo from a week ago with one from today, and it looks like they took out one of the big support columns.

Would be curious to know the story.

Good catch, I wouldn't have noticed that. I'll keep an eye on that for the next photos. Maybe it'll get rebuilt. I'm almost afraid to know the story.

Marshal · #**880** Posted **Apr 24, 2016, 9:24 AM**

Quote:

Originally Posted by mcminsen

Good catch, I wouldn't have noticed that. I'll keep an eye on that for the next photos. Maybe it'll get rebuilt. I'm almost afraid to know the story.

that is an odd one