Where Kentucky State Route 4 skirts the northwestern edge of the city of Lexington, Kentucky, the multi-lane limited access highway is known as New Circle Road. During the summer of 2015, the widening of New Circle Road commenced between US Hwy 60 (Versailles Road) and US Hwy 421. Estimated at $53.2 million, the work consisted of approximately 3.2 miles of lane additions, in each direction, as well as shoulder widening, on-ramp and exit ramp realignment and bridge widening.
Additionally, a number of retaining walls were required throughout the project to provide the necessary grade transitions with the proposed highway improvements. Among the most burdensome to the project schedule and budget were eight drilled pier soldier pile cantilever retaining walls. Several of these structures had maximum exposed heights in excess of 15 feet with minimal set-back from the available right-of-way.
Almost immediately following award of the contract, the general contractor began working with Redi-Rock of Kentuckiana and the Kentucky Transportation Cabinet to explore value engineering alternatives for the costly and time-consuming drilled pier retaining wall structures. As consulting engineers to Redi-Rock of Kentuckiana, JC Hines and Associates was called upon to “make it work.”
The initial structural evaluation and preparation of Redi-Rock material quantities for all eight walls was accomplished by the JC Hines team in 3 short days. Armed with reliable material quantities, Redi-Rock of Kentuckiana was able to confidently offer a furnish-and-install proposal to the general contractor for the Redi-Rock value engineering alternative. Within hours, Redi-Rock of Kentuckiana’s proposal was accepted and JC Hines and Associates was released to prepare preliminary design drawings with supporting structural calculations for review by KYTC. There was only one catch… the extensive preliminary design submittal needed to be completed in just over 24 hours! As it turned out, demanding deadlines would prove to be only one of the many challenges facing final approval of the Redi-Rock value engineering proposal.
In the end, JC Hines and Associates completed the design of 9 Redi-Rock retaining wall structures for New Circle Road. The Redi-Rock Ledgestone walls, totaling nearly 41,000 square feet, saved critical weeks in the overall construction schedule and delivered a savings to the project of over $450,000.