Trenton Biogas Tank Remediation – Releveling and Underpinning
Presented by
Dr. Rick Deschamps, P.E. & Nathaniel Witter, P.E., B.S., from Nicholson
Trenton Renewable LLC operates a food waste recycling and renewable energy production facility in Trenton, NJ. They have an anaerobic biodigester system consisting of 4 tanks and a high-efficiency cogeneration power plant. The tanks were put into service in 2019. It was noticed shortly after the tanks were filled that settlement was occurring. Trenton Biogas began regular survey monitoring and additional geotechnical investigation to track and explore the issue. At 3 years of operation there was up to 6.7-inches of differential settlement and 3 of the 4 tanks were out of tolerance for full operation. Nicholson was contracted to develop and design an underpinning system to stop the settlement and to relevel the tanks. The final approach was to install micropiles to support the tank concrete slabs and utilize the micropiles as reactions to strategically lift the slabs back within tolerance of 1:200. This presentation will review the design approach, micropile underpinning, concrete slab jacking, and performance monitoring to successfully stop settlement and remediate the differential settlement of the tanks.
Dr. Deschamps is Vice President of Engineering with Nicholson Construction, the North American subsidiary of Paris-based Soletanche-Bachy, one of the world’s premier geotechnical general contractors. He is responsible for overall engineering and quality control efforts with emphasis on design build, alternative design, and value engineering efforts. He plays a lead role in recruiting and training of technical staff. His academic and consulting engineering experience provides Nicholson with significant capabilities in advanced analyses and in the understanding of soil and rock behavior. His experience includes design, quality control and implementation of projects involving deep foundations, retaining structures, ground improvement, ground modification, slope stabilization, and earth-fill and concrete gravity dams.
Mr. Deschamps holds a Ph.D. in Geotechnical Engineering from Purdue University and a Bachelor’s and Master’s Degree in Civil Engineering from University of South Florida. Mr. Deschamps is a registered professional engineer in the states of Kentucky, Indiana, Pennsylvania, West Virginia, Ohio and Florida.
Mr. Witter joined Nicholson’s Engineer Development Program (EDP) in 2014 and traveled the country working as a project engineer on numerous geotechnical construction projects. He began the role as an Assistant Project Manager in 2017. Since then, Nate was promoted to Project Manager in 2020 and has been a key member of Nicholson's Mid-Atlantic Region operations team. Throughout is 10 years with Nicholson he has acquired experience on a variety of geotechnical projects covering post-tension anchors, compaction grouting, permeation grouting, void grouting, auger cast piles, soil nail walls, helical piles and micropiles. He is a member of the American Society of Civil Engineers, Association of State Dam Safety Officials (ASDSO), and sits as a voting member on DC-35: Prestressed Rock and Soil Anchor Committee for the Post-Tensioning Institute since 2021. He holds his Professional Engineering license in the state of Pennsylvania.
