Barge Anchored by Steel Piles

[BONILL]

A barge carrying 700 Tons of added weight (7 motors) plus its own weight is to be anchored using driven steel pipes (piles), (48” diameter, 5/16” thick) that run 34 meters deep into the sea bed. The barge is to have free vertical movement while its lateral movement is to be transferred to the pile cap through bumpers, so it seems that only lateral loading of the piles would be important to consider.

The geotechnical report states that the allowable lateral load for the piles is 10 Tons.
I really need some guidance, since most of my experience is based on designing building structures. Some of the questions that come to mind are the following:

1)What lateral loads to consider. Certainly Seismic loads, but what type of structure would it be? Should I treat it as a cantilever structure? While considering loads related to the tide, is there a way to consider or estimate the lateral load as a percentage of the load supported by the barge and the weight of the barge itself?

2) What detailing goes into achieving that fact that the piles would permit the barge to freely move vertically while restraining it laterally? Should there be a fixed connection that the pile head? Is there a special detail of the piles at the sea bed?

3)Any other thing that I might be missing.

Thanks for your time.

 

[BigInch]

I would not try to relate horizontal forces to barge displacement weight. Drag forces are shape based.

Water depth?

Current, wave and wind load on the barge. Start with getting the dimensions of the barge. You'll need that for drag calculations from wind, wave and current velocities. Check shoaling depth for waves and include wave shoal height. There may be wave currents with shoaling. Maximum current load is with maximum ballast. Maximum wind load is with lightest ballast.

Seismic loads are mass based, including water displaced. F = ma

Piles are cantilevers for lateral load purposes.
Do not forget the current and wave load impinging on the pile itself.

Bumpers should be continuous for required tide height. Calculate howser loads at max vertical angle. That may give some vertical component.

You may also want to consider a barge crash force at the wind and current driven barge velocity.

Independent events are seldomly independent.