pedestrian pier construction

[watercop]

My county rehabbed a section of an old bridge to serve as a fishing pier. It was done several years ago by public works (not a contractor) under a cloud of scandal concerning illegal dumping, etc.

At any rate what they have is 3x8 nominal (2.5 x 7.25 actual) joists on 24" centers spanning 13'-1". Atop that is 2x6 decking. I believe the wood is all #2 PT SYP, typical here in Florida.

I'm an engineer but not a structural engineer.

My questions are what is the live load for this service - some surfing suggested 85 psf, and is the described construction adequate to the service?

My concern is that one of these years we'll have a better than average shrimp run on the river and the pier will attract crowds of families...

I don't want to make trouble for the county but want to assure myself of the pier's safety.

 

[msquared48]

Areas of public assembly - 100 psf.

Mike McCann
MMC Engineering

 

[JAE]

Mike, I agree that 100 psf might be appropriate - but public assembly term is from the IBC which is for buildings. I'm not sure that a pier counts as a building or even if the IBC applies at all - also I don't know if AASHTO would apply here either if it is not a pier to be driven on.

If trucks can drive on it would no HS20 truck live load apply? Are there "pier" codes out there?

 

[msquared48]

I know JAE. But I would use no less. I can't imagine trucks driving onto a public fishing pier unless there are commercial fishing boats that moor there too. Yea, I know that there are stupid people too. [rolleyes]

After all, what is a pier but a deck over water? Put a lot of people on it, then it is an assembly area.

Mike McCann
MMC Engineering

 

[watercop]

Thanks for the comments so far.

Pier is strictly for walking and is not configured for boat docking other than at one spot too shallow for all but one or two small recreational vessels.

Pier has a barricade blocking wheeled traffic, although I'm sure the county gets out on it with light weight offroad maintenance vehicles such as a Mule.

County learned the hard way during rehab not to drive out on it - one of their F350s dropped its front end through the deck boards - a pier bent saved it from dropping all the way in.

Any idea how to determine the suitability of 3x8 joists, 24" OC for this service? All the span tables I've browsed consider only 2x lumber.

Thanks again!

 

[BAretired]

Use the tabulated values for 2x8@24 times 2.5/1.5.

BA