Trench Cover plate for pedestrian Load 1

[Elizabethstructures2]

I am asked to design and detail a flat 3/8" diamond plate with reinforcing to withstand pedestrian loads as a trench cover plate. this plate will sit in a CIP angle frame.
I have not used pedestrian loads before - is it 100psf? Is there a common way these are designed? Would the reinforcement be angles welded underneath the cover plate? Any insight would be great - I know this has to be done often - I just haven't done it before!

Thanks!

 

[jhnblgr]

Depending on application you might simply want to look into road plates to use

 

[271828]

More info is needed.

What is the standard for loads on this project? ASCE 7?

What is the Occupancy or Use, to use ASCE 7 Table 4.3-1 terminology?

 

[LittleInch]

Why??

Just buy then. Google pedestrian trench cover.

They make them out of plastic.
Like This

Plastic Trench Cover

High-impact plastic trench cover with steel reinforcement, handles for single-person lift, and 400kg load capacity. Bright yellow for visibility, anti-slip and anti-trip surface ensures safety on footpaths. Ideal for utility works and temporary trench board applications. Size: 1200mm x 800mm...

hermeq.com

 

[Elizabethstructures2]

It is a government communications building, and they are doing some underground utility trenches, so I am not sure which live load occupancy it is. The electrical engineer is specifying for a delegated engineer to design the trench cover plates for 'pedestrian load'. I think 100psf covers that but if not i will get comments back.

 

[Elizabethstructures2]

Why??

Just buy then. Google pedestrian trench cover.

They make them out of plastic.
Like This

Plastic Trench Cover

High-impact plastic trench cover with steel reinforcement, handles for single-person lift, and 400kg load capacity. Bright yellow for visibility, anti-slip and anti-trip surface ensures safety on footpaths. Ideal for utility works and temporary trench board applications. Size: 1200mm x 800mm...

hermeq.com

View attachment 15677

This needs to be a steel permanent cover plate flush with the top of slab - it will sit in a depressed steel angle frame.

 

[271828]

It is a government communications building, and they are doing some underground utility trenches, so I am not sure which live load occupancy it is. The electrical engineer is specifying for a delegated engineer to design the trench cover plates for 'pedestrian load'. I think 100psf covers that but if not i will get comments back.

If given no other info than that, I'd design for 100 psf or 300 lb, representing a pretty big guy standing on it.

 

[jhnblgr]

Home

Home page for Trenwa, Inc. manufacturer of precast trench solutions for cable and piping.

www.trenwa.com

 

[LittleInch]

This needs to be a steel permanent cover plate flush with the top of slab - it will sit in a depressed steel angle frame.

Same thing. Just buy them from the culvert vendor.

No point in reinventing the wheel.

 

[EngDM]

There are equations to calculate plate stress for plates supported on four sides in "Design of Weldaments - Blodgett" that I have used for this in the past. The FLRPLATE spreadsheet found here uses the same equations, although it is ASD design. There are also tables 3-18a and 3-18b in the AISC Steel Construction Manual (15th) for this that show max spans under service and strength.

Hope this help, but I do agree with others that getting a plate from a vendor is probably easier.

FYI, 100psf is probably the correct load to use, and the deflection requirements are more lax than your typical L/360; the AISC book has it at L/100.

 

[JoelTXCive]

If the plate is going to sit in an embedded angle, then would a piece of grating work? There are lots of span tables available for grating.

Google "Type 19-4 Grating"



Also, is this plate (or grating) going to be in a spot accessible by the public? Or in a maintenance area?