Proposed design chart of mechanical joints on steel-PHC composite piles

A fundamental study of a mechanical joint in a steel-PHC composite pile subjected to combined loads was done using three-point bending tests and 3D finite element analyses. The three-point bending tests were conducted to evaluate load-deformation response, strain distribution on the pile, ultimate bending moment and failure mode of the mechanical joint on steel-PHC composite piles. In addition, 3D finite element analysis for the mechanical joint was performed and then, the stress distributions and the maximum load resistances of each parts of the joint were estimated by comparing the calculated stresses to the yielding stresses of the joint materials. The 3D numerical methodology in the present study represents a realistic mechanism of mechanical joints. Through detailed numerical analysis, it is found that the behaviour of mechanical joint of composite piles shows safe side under working load. Based on these results, the design chart for steel-PHC piles has been proposed to be convenient for preliminary design stage which can be used to evaluate the safety of mechanical joints.