Design of concrete diaphragm between concrete filled pipe piles
Design of concrete diaphragm between concrete filled pipe piles
(OP)
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.





RE: Design of concrete diaphragm between concrete filled pipe piles
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.
RE: Design of concrete diaphragm between concrete filled pipe piles
RE: Design of concrete diaphragm between concrete filled pipe piles