when does equipment have to be anchored to the floor and what forces to use for design

[vato]

I am designing a structure, let's call it a bench/sculpture to be installed in a renovated pier building in San Fransisco.
I have designed it as an architectural component in order to determine forces, but the owner does not want to bolt it to the concrete floor because of heat tubing. The structure is designed to resist overturning moment without any tension anchors but I have no way to resolve
the shear force at the floor/structure interface per code since I can't rely on friction as an architectural component. This thing weighs 4,000 lbs with a dead load contact pressure of 150psf, meeting the maximum dead load allowed per the EOR. The EOR has not given any direction concerning this yet which is also confusing. Am I missing a specific code section that can give guidance here? Thanks for the help.

 

[MiketheEngineer]

Glue it...

Any chance of a small cable to ceiling??

 

[oldrunner]

Somehow the sculpture has to be fastened to the structure - be it adhesive or struts to some solid connection. The EOR is the person who should be determining this - especially since the sculpture will be seeing amplified lateral seismic loads. There should be an official set of calculations generated certified by a professional civil or strutural engineer.

This sculpture can "walk" across the floor during a seismic event - ("coming soon?").

If you have to use bolts - x-ray for the water pipe locations and space your inserts between the pipes.

 

[jmcoope3]

If you didn't have the pipe going to it, i'd say put it on sliding castors. Anchorage provisions are invalid if the anchorage interrupts the intended functionality of the equipment (statue?).

4000lbs does put you into the danger zone, typically anything over 400 when connected to the floor (or cg's 3ft off the floor? [the coast i'm on still works ASCE 7-05]). Seismic Anchorage is a service provided by most seismic design companies... out in California it's pretty cut-throat so finding a company able to design/stamp anchorage probably won't be too tough. The importance factor of the piece is a 1, it's a statue so it's probably pretty rigid so lets use a forgiving ap and Rp (~1/3 for the ratio, i could dig through the code to try and find the exact... but that's someone else's job) and an Sds of 1 for Sanfran, i'll assume grade because what's a water filled bench sculpture if it's not in the lobby?

Fp=~0.25 if these assumptions are true, so your shear is about 1000# total (ASD). 4 Anchors and you should be fine.

 

[jmcoope3]

four 1/2" diameter 2" embedment ESR rated mechanical anchors... unless the thing is like 10 feet tall.

 

[vato]

thanks everyone,
The actual design of the anchor is not the issue. I am looking for the minimum weight or force, along with the code section which then specifically requires anchoring. I've been very clear that I believe the piece requires shear anchors. (also, the floor is elevated in a pier structure and would amplify the forces) I'm hoping the EOR chimes in before I do.

 

[dik]

One time, in Toronto, the wind 'funnelling' between the TD Towers was moving a large metal sculpture laterally... It was a huge structure, maybe 20' or 30' high being blown horizontally...

Dik

 

[vato]

Now I'm working on a 2,000 lb dining table. I'm comfortable as an engineer requiring a connection to the structure, if the piece is in high risk area, but I'm still not clear on where in the code it is explicitly required. There seems to be some judgement required on the part of the engineer and I'm not sure why.

 

[jmcoope3]

Typical anchorage requirements for floor mounted equipment is laid out in ASCE 7 in chapter 13. Most buildings in my area are still under 05, but typically as the numbers get higher the requirements get tighter.

From what I get form ASCE 7:
Anchor equipment on floor with weight greater than 400lbs or center of gravity over 4ft. There's exemption for furniture and other non-structural - non-continued use of building stuff. If failure of the connection to the structure in a seismic event could cause injury to surrounding people or hinder peoples ability to leave, you probably have to look into it.

 

[vato]

Thanks jmcoope, that's exactly what I'm looking for but I can't find the 400# or 4' numbers in ASCE7-05. Nor could I locate anything on furniture exceptions. Can you provide a little more guidance here? thanks

 

[jmcoope3]

So, lets explore the ASCE maze real quick (7-05)

Start at CH.13, Seismic Design Requirements for Nonstructural Components:

13.1.4, 4.b. gives you exemptions (weight/height)

Design requirements for non structural components are in 15.3.2, but i'd follow basic procedures in 13.