Acceptable loading? 1

[adiem]

I am in the process of designing an industrial platform to provide access to a process vessel. The only loading the platform will take is from personnel. Could anybody help by letting me know an acceptable design loading for the platform based on the above? Is there a standard that quotes this design load (preferably British)

T.I.A

 

[SlideRuleEra]

I can't help you with a British standard, but a typical uniform live load for an elevated platform is 60 pounds per square foot (International Building Code 2000) - also ASCE 7, if I remember correctly.

However with that said, please consider this possibility:
Will people be the only live load on an industrial platform?
Maybe equipment parts may be placed on it or perhaps heavy tool boxes. I would suggest using at least 100 pounds per square foot as the uniform live load criteria and possibly take a look at the potential for point loading also.

 

[adiem]

Thank you 'slideruleera'

 

[Lutfi]

I designed many platforms (fixed and moveable/articulating). It would be prudent to check with the user on how and what they plan on doing with the platform. Here is what I have used in the past:

1. Design for 60 PSF uniform load.
2. Design for 30 PSF uniform load plus concentrated load of 1000 pounds over an area 2.5'X2. 5’ that can be any where on the platform.

I think 100 PSF may be high. However, if the paltform is small, it may not be that big of a deal to design to 100 PSF.

I hope this helps

 

[SlideRuleEra]

Lutfi - At one time I considered 100 PSF to be quite conservative, then two things happened about 15 years ago:

1. At an 5 year old electric power station that I had worked on, noticed that platforms with steel bar grating (rated at 100 PSF) had numerous large, deep "dents" in them where operations personnel had placed (dropped?) equipment parts.

2. On an ASME sponsored tour of a pulp and paper mill, the guide asked everyone to "gather around closely" so that we could hear him over the equipment noise. We were on a small elevated platform (about 100 ft. off the ground). The 25 men, including me, crowded in to an area that I realized was about 5 ft. x 10 ft. Since some of men were "large", I guessed that the average weight must be about 200 lb each. - All of a sudden, 100 PSF live load capacity did not seem unreasonable for an industrial platform.

Best Wishes

 

[Lutfi]

SlideRuleera,

I agree with you. That is why I said that it would prudent to gather all data from the user.

My loading comes from working on Aerospace launch pads platforms. All of the platforms that I design get proof loaded to 125% due to their proximity to flight hardware.

I definitely would like to be on the conservative side. This saved me butt many times when clients came back to me and asked to increase or change the use of their structures.

Regards

 

[dicksewerrat]

I guess I'd check into the relavent Safety regulator too. Osha has specific guidelines for worker areas in the US. sorry i don't have the number of the section.

 

[dbuzz]

We'd normally use the worst case of a 2.5kPa (52psf) uniform load and a 1.4kN (0.3kip) point load for the live load allowance on an access walkway 600mm to 750mm wide.

If the walkway is a bit wider, or adjacent to machinery where equipment components could be placed during maintenance, we'd use the worst case of a 5.0kPa (104psf) uniform load or a 4.5kN (1.0kip) point load for the live load allowance.

 

[JoeTank]

I have seen very few large project specifications that do not require at least 100psf for work platforms. If it's not 100 psf, its usually higher. Similar requirements for large EP&C firms often noted.

Steve Braune
Tank Industry Consultants

http://www.tankindustry.com