Find out more OK
The Kentucky Lock is located in Grand Rivers, Ky. on the Tennessee River. Based on feasibility studies completed in 1992, a recommendation was put forward for the construction of a new lock adjacent and landward of the existing lock in order to improve barge traffic. Overseen by the Nashville District US Army Corps of Engineers, construction began in 1998 for the sitework and bridge construction. In 2010, construction of the upstream monoliths for the lock was awarded to Thalle Construction Company, Inc.
Thalle Construction, being a long standing customer and owner of Doka’s Framax Forming System, sought the experience of Doka to provide concepts and drawings for the multiple monolith concrete placements. Thalle Construction and Doka’s Atlanta, GA branch worked side by side to develop formwork systems that provided the contractor with solutions tailored to the jobsite requirements. The solutions that were agreed upon included one-sided climbing formwork in the form of Doka’s D-22 Dam Formwork and Doka’s Supporting Construction Frames, Dokaflex and 10K Shoring Systems to support the large 15’ thick culvert slabs, and a large quantity of Framax wall formwork used in combination with wood forms built by Thalle Construction.
One of the major obstacles encountered by the project team was that a majority of the concrete placements were classified as mass concrete. Mass concrete placement is defined as “any volume of concrete large enough to require that measures be taken to cope with generation of heat from hydration of the cement and attendant volume change, minimize cracking.” In this instance, Thalle was placing low slump concrete at an average height of 4 to 5 feet in depth and therefore required formwork to accommodate this type of concrete. Doka addressed this issue by providing Thalle with its D22 dam formwork system. Doka’s D22 is designed for forming heights up to 4.0m in height (approximately 12 feet) and is tieless. This system, both in its starter block and climbing system form, allowed Thalle to place concrete for two successive lifts before having to raise the system for its next monolith placement, thus making it cost effective during the overall course of the project.
Some unique structural features had to be accommodated as part of the forming systems design. Multiple embeds and anchor bolts protruded past the face of the finished concrete and caused interference with the face of the formwork. This involved real time conversations between Doka’s design team and the contractor in order to ensure that these parameters were met to the client’s satisfaction prior to placement of concrete. It often involved using a combination of Doka formwork and job built formwork to accommodate the varying situations.
The project had to be carefully sequenced since formwork for one side-by-side monolith could not be removed until the other monolith was complete. All monoliths required individual drawings for each lift that were required to be submitted and approved prior to construction commencing. This created its own challenges because it could be as long as 180 days between completion of monoliths drawings and receipt of final approval from the projects agency. Working together, Thalle Construction and Doka have been able to adapt to the changing environment of this project.
Due to the nature and location of some of the concrete placements, Doka has also had to get a little creative in its form design in order to respond to the contractor’s needs on this project. Some areas of this project restricted the contractor from using a full blown form system and as a result a more traditional or “old school” system had to be incorporated into the form systems design in order to surpass some of the obstacles the contractor was encountering on a regular basis.
The project is currently valued at approximately $63 million and is approximately 50 percent complete.