Evaluation and Design for Wharf Berth Improvements

The North Carolina State Ports Authority (NCSPA) has undertaken improvements to its Morehead Port berth facilities, to better serve the deeper draft vessels utilized in today's shipping industry. In general, the improvements include a layer of tieback to aid in carrying additional live loads from a recently constructed warehouse, and a combination of additional layers of tiebacks and a king pile wall system to stabilize the existing wall during the future removal of an existing rock berm and dredging along approximately 213.4 meters (700 feet) of the mudline to a deeper elevation. The Ports Authority commissioned an engineering study to determine a feasible approach to accomplish the improvements. The engineering study included a subsurface exploration to assess the subsurface profile, engineering properties of the in-situ soils, and configuration of an existing relieving platform behind the current wall system. The subsurface profile model was utilized in a detailed soil-structure interaction (SSI) analysis to design the new wall system. The design of the new wall system implemented innovative methodologies and construction sequencing to minimize the effects of the new wall on the existing wall system and warehouse. This paper highlights key features of the project. It describes the background information; project description; the design methodologies; soil exploration and determination of engineering parameters used in the SSI analysis of the new wall system; and incorporation of practical construction issues in the design.