Seismic Performance of Pile-Wharf Connections: Fid-Bau Portal

Seismic Performance of Pile-Wharf Connections

Lehman, Dawn E. / Brackmann, Emily / Jellin, Amanda / Roeder, Charles W.

Pile-supported marginal wharves are a critical infrastructure component of ports. Experience from previous earthquakes indicates that the connection between the pile and the wharf deck is a major source of damage during and earthquake. Previous studies indicate that although connections designed using current guidelines can maintain cyclic drift demands, they sustain damage and initiate strength deterioration, even at low levels of drift. Therefore, there is an interest in improving the performance of precast pile connections. A study to improve the performance of pile-wharf connections, part of the NEES-GC Seismic Risk Mitigation of Ports, was undertaken to develop damage-resistant connection. The results of the study and associated performance tools are summarized. To mitigate the pile and deck damage, several structural concepts were evaluated including (1) intentional debonding of the headed reinforcing bars, (2) supplemental rotation capacity through the addition of a cotton duck bearing pad and (3) supplemental material to sustain the lateral deformations while minimizing deck damage. The test results show minimal damage and strength loss relative to current practice and achieving performance-based design objectives. These results have been combined with prior test results on connections. By separating the connection responses by categories, individual connection-rotation based fragility curves have been developed for three repair-specific damage states. These curves would be appropriate for performance-based evaluation of older, current, or innovative connections in port construction.