Steel Sheet Pile Wall Wale Rehabilitation

Catalyst Paper Corporation's "A" Dock is located on the Georgia Strait on the west coast of British Columbia, Canada. "A" Dock is a deep-sea port structure used to load paper onto sea-going barges. The facility consists of a steel sheet pile pier supporting a warehouse. The steel sheet pile structure had experienced significant structural deterioration since its original construction. Recent inspections determined that the tie-rod to wale connections had lost significant cross-section due to corrosion, and seven consecutive connections had become completely detached, reducing the load carrying capacity of the structure significantly and inducing increased moments in the steel sheet piles. As a result, significant lateral wall movement, subsidence, and damage to the structures supported by the sheet pile wall had occurred. The decreased structural capacity required load restrictions to be implemented that substantially reduced the utility of the warehouse facility. The steel sheet piles were determined to have considerable residual life and rehabilitation of the structure was feasible. Repair options were limited by the advanced deterioration of certain components of the structure, the client's requirement to maintain operations during the repair program, and the structural requirement to maintain tension in the tie-rods. The section of the structure that exhibited the most advanced deterioration was rehabilitated using a new internal wale connected with a unique tie-rod extension to reconfigure the tie-rods to bear on the internal wale. Other sections of the structure were rehabilitated with an external repair replacing the tie-rod to wale connections with a cost-effective, easy-to-install connection detail that re-tensioned the existing tie-rod. The project was completed on budget and schedule, with no interruption to operations, allowing Catalyst Paper to continue shipping product at approximately 5% of the cost of a replacement structure.