Project Value
Project Manager:
Jason Burton, PE
The Project
When the Tennessee Department of Transportation (TDOT) began the I-75 Interchange at I-24 Phase II project to provide a direct connection to downtown Chattanooga, the City of Chattanooga seized the opportunity to replace and relocate two sanitary sewer undercrossings that conflicted with the project. As the lead designer for the TDOT I-75 Interchange at I-24 Phase II design-build, RK&K was selected by the City to provide design and engineering support services for the associated I-24 sewer relocation project.
The undercrossings included a 15-inch reinforced concrete pipe (RCP) sewer near McBrien Road overpass and a 12-inch RCP sewer just west of the Belvoir Avenue bridge. The 15-inch sewer was designed and constructed in the early 1930s, well before the construction of I-24; and the 12-inch crossing was constructed in the 1960s.
From CCTV investigations, the City discovered that the 15-inch sewer had a number of offset joints and other structural defects such as visible surface aggregate, circumferential cracking, longitudinal cracking, and a sag.
The investigation also uncovered that the 15-inch sewer had an active inaccessible manhole buried underneath one of the travel lanes of I-24. An assessment of the 12-inch sewer crossing revealed the pipe had several overset joints, evidence of surface spalling, deposition of debris of varying size, and a sag.
With two projects, managed by two different clients, being designed and constructed simultaneously, RK&K kept open lines of communication between the utility and roadway design teams, facilitated close coordination among stakeholders, and worked collaboratively with the City, all while providing innovative solutions to resolve unique design conflicts.
As a result, RK&K delivered a solution that prioritized long-term value over short-term savings to ensure lasting infrastructure durability.
On November 10, 2025, RK&K was presented with an ACEC/TN Grand Award at the 2025 Engineering Excellence Awards banquet in Nashville, TN.
When the Tennessee Department of Transportation (TDOT) began the I-75 Interchange at I-24 Phase II project to provide a direct connection to downtown Chattanooga, the City of Chattanooga seized the opportunity to replace and relocate two sanitary sewer undercrossings that conflicted with the project. As the lead designer for the TDOT I-75 Interchange at I-24 Phase II design-build, RK&K was selected by the City to provide design and engineering support services for the associated I-24 sewer relocation project.
The undercrossings included a 15-inch reinforced concrete pipe (RCP) sewer near McBrien Road overpass and a 12-inch RCP sewer just west of the Belvoir Avenue bridge. The 15-inch sewer was designed and constructed in the early 1930s, well before the construction of I-24; and the 12-inch crossing was constructed in the 1960s.
From CCTV investigations, the City discovered that the 15-inch sewer had a number of offset joints and other structural defects such as visible surface aggregate, circumferential cracking, longitudinal cracking, and a sag.
The investigation also uncovered that the 15-inch sewer had an active inaccessible manhole buried underneath one of the travel lanes of I-24. An assessment of the 12-inch sewer crossing revealed the pipe had several overset joints, evidence of surface spalling, deposition of debris of varying size, and a sag.
With two projects, managed by two different clients, being designed and constructed simultaneously, RK&K kept open lines of communication between the utility and roadway design teams, facilitated close coordination among stakeholders, and worked collaboratively with the City, all while providing innovative solutions to resolve unique design conflicts.
As a result, RK&K delivered a solution that prioritized long-term value over short-term savings to ensure lasting infrastructure durability.
On November 10, 2025, RK&K was presented with an ACEC/TN Grand Award at the 2025 Engineering Excellence Awards banquet in Nashville, TN.
Client
Market
- Municipal
