The Queensgate Operations Center for Duke Energy, located in Cincinnati, Ohio, is a primary support operations center for gas and electric services through the greater Cincinnati area. This facility includes a supported plaza storage/parking area adjacent to a multi-story office/service building. Starting shortly after construction, a substantial leak developed between the office building and the plaza area. basement-level offices and staff areas adjacent to the plaza had endured seventeen continuous years of unresolved leakage, despite repeated repair attempts.

 

StructureTec was called upon to investigate and identify the cause of the continued leakage and to design appropriate repairs to stop the leakage and provide dry working conditions at the Queensgate facility..

 

In order to identify the source of leakage, StructureTec conducted test openings in the plaza slab abutting the office building to confirm original construction detailing, verify existing conditions, and identify the source of the leak. StructureTec found that the leak was related to the original design and detailing of the waterproofing at the expansion joint between the plaza and the office building.

 

The project was executed via StructureTec's Premier Engineered Projects, a design-build delivery method. StructureTec's construction team, Construction Services Group, performed repairs to stop the leakage at the Queensgate facility. To address the leakage problem, a 10-foot-wide strip of the plaza abutting the office building was removed and continuous waterproofing was installed across the structural slab and expansion joint. Higher capacity underslab drainage was provided along with back slopes along the building to divert water away form the joint. Temporary weeps through the end dam were provided, as well as additional membrane-level drains along the north end. Surface level joint sealants within the designated work area were replaced to help limit moisture ingress to the plaza subsystem.

 

After completion of the project, flood testing was performed to ensure the new area was watertight. The water level was maintained and no evidence of leaks below the test area were found after a 24 hour time period.