Turning Basin Wharves Prepare for Deepening

Abstract: The Turning Basin terminal is one of the oldest terminals as part of Port of Houston Authority (PHA). The terminal is located 5 miles from central Houston, downstream of Buffalo Bayou. This terminal consists of over 20 wharves that were constructed in the late 1940's. These wharves vary in structure and continue to play a critical role operationally. Tenants routinely berth vessels upwards up to 750' to unload project cargo and breakbulk commodities.

The wharves have deteriorated and the PHA has performed several repair and rehabilitation dock projects to extend the service life. In 2026, the USACE plans to deepen the turning basin federal channel from -37 MLLW to -39 MLLW as the final segment of Project 11. As a result, the PHA is undertaking several wharf deepening projects to prepare the existing wharves for the deeper channel and berth pockets. The wharves 9 and 16 project consists of performing global stability analyses to determine the existing and future factors of safety (FOS) for the deeper channel and berth pocket as well as rehabilitation of deteriorated elements within the structure.

This presentation covers the constraints, analysis and optimization techniques used to design the Wharves 9 and 16 rehabilitation project.

The design team performed global stability analyses utilizing a combination of SLIDE and PLAXIS to determine the FOS for the current and future dredge conditions. Preliminary results from SLIDE were confirmed in PLAXIS to account for the effects of the global soil structure interaction. It was determined that a series of drilled shafts installed in the backlands, just behind the sheet pile cells, for Wharf 9 and 16 provided enough capacity to achieve minimum recommended FOS. Multiple load cases were evaluated considering undrained, drained, and fully softened soil strength with the fully softened cases controlling the design. Drilled shafts were utilized to minimize settlement of the cohesionless fill within the existing cell system as previous pile driving operations had caused pavements to settle.

An underwater inspection performed at Wharf 16 revealed severe corrosion resulting in holes in the flat sheet piles. Repairs were made by welding plates over the holes to prevent soil loss and further deterioration. A new sheet pile wall was installed in front of the existing cell structure and flowable fill was poured behind wall. The new bulkhead and flowable fill encapsulate the existing cell wall to prevent further deterioration. The front beam of the wharf was removed to allow for the installation of the new bulkhead wall and the existing fender system was temporary supported while the new bulkhead wall was installed. The new bulkhead had a pile tip elevation deep enough to further improve the global stability and was considered in sizing the drilled shafts in the backland.

Port Houston and the project team reduced the project costs of the improvements for global stability while complying with the project constraints. These expansions will assure the turning basin terminal will continue to be an asset to the PHA after the Project 11 deepening.

How does this project / topic contribute to the advancement of the industry and profession?: There are aging wharves across the US that are required to continue past their useful life and accommodate deeper channels. This abstract illustrates rehabilitation and accommodating for channel deepening can be cost effective. This can help Ports across the US face these challenges.

Does the project / topic implement new and innovative techniques, materials, technologies, and delivery methods?: Yes, plaxis was used to optimize the geotechnical solution to reduce construction costs.

What was the most challenging aspect of your project / topic and how did you handle it to ensure success?: Optimizing a solution for both rehabilitation and accounting for future dredge depths. Used robust analysis tools to reduce cost.

Who is the target audience for this paper?: Port Engineers and Port Authorities with channel deepening projects with aging wharves.