Lateral analysis of steel cased piles

[Kijana]

First of all, what are the advantages of steel cased piles over steel pipe piles in a marine environment?
Is there any software that would be useful in analyzing steel cased piles subjected to lateral loads?

 

[kostast88]

The steel case will be driven in the bottom of the sea. Later it will be filled with concrete to produce a RC steel-cased pile. The case is it's formwork. It's essentially a concrete pile. This pile is pretty rigid. Concreting in marine environment is problematic.

Steel piles are slender, have water on their interior and are prone to corrosion. You have no access to stop & remedy the internal corrosion. So the steell piles would have thick walls to account for the loss of section over the years. Another factor is that they can displace a lot. They are cheaper.

Plenty of software: PLAXIS, MIDAS, SOFISTIK, etc etc.

 

[centondollar]

Make them batter piles and concrete them and reinforce them. That way, you won´t have to deal with the headaches related to uncertain bending stiffness (the steel casing, driven or drilled, will not prevent concrete from cracking) and the soil-pile model (advanced FEM, linear spring, nonlinear spring etc.), and as an added bonus deflections and capacity will be a non-issue due to very large axial stiffness and strength of reinforced and concreted steel pipes.

 

[BridgeSmith]

Don't know about the marine environment, but there's some information out there about using those for bridge foundations, except we call them concrete filled steel tubes (CFST).

Rod Smith, P.E., The artist formerly known as HotRod10

 

[kostast88]

I used a little program in the past to do pile analysis. I couldn;t remember it before but found it in my old hard drive.

It's called PyPile, and you can use it for free for some time: Link

It performs lateral analysis of piles in soil. You can add the sea current + wave forces as point loads.

 

[centondollar]

Lpile would be preferrable if you use a commercial software specifically for pile design, since it is older, better documented and comes with several add-on modules. A more guaranteed way of "getting it right" is to make the p-y curves in excel by yourself and input them into a general-purpose FE program, or to use a more sophisticated (or simplified, e.g., batter pile arrangement with frame analysis) model.

It´s also worth remembering that the p-y curves cannot properly model loss of contact, inertia or hysteresis, so they are not ideal for completely dynamical loading (waves and currents).