Engaged by Create Ltd, the EnLink expert team came up with this practical and cost effective remedial solution for a screw pile head connection. The connection is intended to resist the uplift demand forces during a major earthquake. 

Finite Element analysis was conducted to ensure that the yielding of the reinforcing bars can provide sufficient ductility capacity before initiation of any failure in steel plates, welds, and the screw pile section.

The final design includes a 40 mm steel cap plate (not shown in the above view) with full penetration butt weld to the internal face of the pile section. The stiffener plates significantly reduce the stress concentration on the cap plate.

 

                                               The deformed shape of the pile section under the foundation load.

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                                               Stress distribution pattern in the steel cap plate using a specific meshing system.

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                                               In-plane stress distribution in the steel cap plate and the screw pile section.

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