Lockport Lock and Canal Wall
Working under two indefinite-delivery indefinite-quantity contracts, Hanson has provided engineering services for the USACE, Rock Island District, involving design for a roller compacted concrete replacement wall (RCC), value engineering study, test plan and observation wells.
The 1905-era 4,300-foot-long west approach had undergone several repairs, rehabilitations and upgrades, but it was experiencing severe seepage, erosion and sink holes. Hanson provided the preliminary design for an RCC replacement wall to replace a portion of the existing concrete canal wall at Lockport Pool. Key tasks involved:
- holding public meetings with representatives from Carrier’s Association; Metropolitan Water Reclamation District; USACE; and the city of Lockport to discuss the condition of the canal and alternatives, solutions and preferences for repairing the facility,
- performing sequencing assessments for the RCC wall construction,
- preparing report with plans, calculations, design documentation appendix, and MCACES II cost estimate, all to a 50 percent level of final plans and specifications in 67 working days,
- designing the RCC wall to replace approximately 2.2 miles of the severely deteriorated concrete canal wall; the height of the wall varies from approximately 19 feet to 43 feet and was designed in accordance with EM 1120-2-2006 “Roller Compacted Concrete” and Portland Cement Association (PCA) publications,
- performing slope stability analyses of the existing embankment and as modified for expected conditions during construction, and
- establishing recommended design criteria from previous geotechnical work performed by the team under a separate task order.
Hanson also participated in a value engineering study for the Lockport Lock and Canal Wall. Our responsibilities included addressing both the geotechnical and structural engineering aspects of rehabilitating the dike, walls and controlling works. The team provided input to identify cost savings for the approach dike, concrete canal walls and controlling works for this aging facility. The driving issues were related to excessive seepage through and under the existing levee. The recommendations involved using cutoff walls to control seepage and yielded significant savings on the estimated $105 million construction costs for the rehabilitation.
The value engineering study led to an extensive geotechnical exploration program. Our team helped to implement this program, which provided information to support the design of a new cutoff wall. This involved a test section plan evaluation. We also installed, developed and tested 21 observation wells within the west approach dike of the Lockport Pool. The observation wells monitored the seepage and associated changes in seepage as a result of the planned construction of a seepage cutoff barrier.