Design of concrete diaphragm between concrete filled pipe piles

[foreng]

Our client has suggested looking at designing re-enforced concrete diaphragm between pipe piles on a pier bent (single row) with a precast concrete cap, approx. 5m unsupported pile length. The pipe piles will be re-enforced/concrete filled. The river in question has some significant ice loads requiring a more rigid bracing system. Looking for some design references or other design information. Trying to determine what factors to consider as the pipe pile rigidity should govern the deflection and moment under lateral loads.

 

[ishvaaag]

You can use the ordinary codes to design the elements of your structure. In the context of bridge, AASHTO provisions would be normally the preferred. So one would look for weldment to the steel sheath or even anchors within the concrete. Provisions for the separate strength of the piles as composite members (in-filled pipes) you have in the AISC code as well. And everything for concrete (splices, reinforcement of shearwall panels or akin) in ACI codes, 318 mainly. Methods of chemical bond for anchors from the providers themselves as by them warranted, or by some code.

If the diaphragm does not come till the precast concrete cap (or ground), you may need to care for the effect of the diminished slenderness in the free part of the columns for earthquake forces, for ductility would be severely diminished. So check the convenience in such case of going to such cap and foundation.

If the region is prone to severe earthquakes, one might dedicate special attention to the ductility of the connections. Maybe a length of the splicing connectors should be left unbonded, or at least everything calculated to stand the number of strong motion cycles that can be expected at the local seismic level.

One might even design the connections to exercise friction at the connection with the diaphragm itself as a way to get controlled dissipation of earthquake forces. This looks as being more than what asked for by the client, that seems just interested in a reinforcement, not a replaceable system of fighting earthquake action.

 

[DRC1]

Try

http://www.pilebuck.com

go to books. the books on marine construction or coastal construction. (You may have to check with them to get the right book)

 

[foreng]

Thanks for the advice