In Situ Dynamic Pile Testing to Realize Wharf Renovation Savings

Improvements to existing wharfs frequently involve larger design loads and hence the need to evaluate the structure’s capacity to accommodate that load. Minimizing renovation to the existing structure, especially the substructure, is ideal from both a cost and facility disruption standpoint. Therefore, maximizing the loads that can safely be supported by the existing substructure is often a goal in a renovation design. This paper presents a case study of high-strain dynamic pile testing performed on 30-year old 18 in. (457 mm) and 20-year old 24 in. (610 mm) square prestressed concrete (PSC) piles to determine the maximum allowable loads the existing piles could support, thereby reducing the number of new piles required to support the increased demands from larger ship-to-shore (STS) cranes. The case study discussion includes a description of the wharf construction, pile testing, results, wharf reconstruction, concluding with the study result’s impact to the overall project design and subsequent construction cost. Following the case study, recommendations for this method’s application to other wharf renovation projects will be provided along with a discussion on balancing the needs of an operational terminal during the in-situ testing.