Structural Analysis Software for Floating Pontoons/Docks 1

[Simba13]

Good Morning all,

I was wondering if any of you have a recommendation for software to perform structural analysis on floating marina docks (concrete). I've just been mostly using hand calcs to get the loads and running it in RISA (this is the way my boss does it). I've spoken with a few people in the field and they say that's fine, but I always feel like I'm oversimplifying a bit. FYI I use miche rungren for wave loads.

Thanks!

 

[DaveAtkins]

I have used RISA-3D to design floating docks for dead and live load, mooring load, and ice load.

DaveAtkins

 

[phamENG]

Simba - unless you're doing nothing but floating docks every day, specialty software won't be worth it. Oversimplification, if taken in the correct direction, is going to give you conservative designs. When dealing with waterfront structures like you are that's typically going to be the best way to do it. If you're building a a multi-million or billion dollar port, then sharpen the pencil. But for a marina or even a small commercial terminal, simple and conservative is the way to go.

 

[Simba13]

Yeah, that seems to be the consensus among the other people I've spoken with. Some of these are heavy duty, the one I'm working on now is 462' long (haven't asked about the price tag) so I just figured I'd confirm with some other engineers. My boss has worked out a very good procedure for the loads and I'm not doubting it or anything. I guess I just get a little cagey when you talk about such a complex loading environment in reality and then simplifying it down. Also I'm a nerd and if I can build a more complex model I'll try to find an excuse to do so.

Thanks!

 

[phamENG]

I'm a nerd and if I can build a more complex model I'll try to find an excuse to do so.

I'm right there with you, but keep in mind this other thing you said:

such a complex loading environment

The more complex you make your model to account for the loading, the more fine tuned it gets to handle that specific load. In such a complex environment, those blinders can be disastrous. Your model has to be equally complex for each complex load if you try to make it that accurate. Some form of the law of diminishing returns certainly applies here, and if you're not careful you'll end up sitting on, at best, an unconservative, upper bound solution to one or two possible scenarios, and your structure will be hit by scenario 63.

 

[Simba13]

phamENG Yep, I definitely get it. I think I'm more or less ready to put the modeling concerns to rest. Although I may bug you guys again in the future about some assumptions for the vertical wave load distribution.

Thanks! phamENG & DaveAtkins

 

[ldeem]

I used to work in offshore and API RP 2A has some pretty straight forward wave load calculations, or at least it was back in late 90's.