Charlotte Area Transit System: LYNX Blue Line Extension

The LYNX Blue Line Extension (LYNX BLE) is the extension of the original Blue Line Light Rail Service. The LYNX BLE consists of a 9.4-mile dual track alignment that extends from 7th Street in downtown Charlotte to UNC Charlotte.

LaBella was responsible for the drainage design including street drainage, track drainage, culverts, and channels. Drainage improvements have ranged from 15-inch to 72-inch pipes, 7’x7’, 8’x6’, 11’x6’, and 12’x10’ concrete box culverts. Some unique features of the project included installation of 36-inch to 72-inch steel pipes by jack and bore methods under Norfolk Southern and CSXT railroads as well as the North Carolina Railroad. A 12’x10’ precast concrete box culvert was installed under active CSXT tracks by jack and tunnel method. Approval was obtained from Norfolk Southern, CSXT, and North Carolina Railroads for extensive work within their corridors.

This project had an extremely aggressive design phase schedule with many moving parts. The deadlines were critical and absolute to avoid impacting subsequent phases of work. The Quality Assurance (QA) process required detailed reviews and QA process approval prior to acceptance of all submittals. The QA process was programmed into the schedule in the lead up to all submittals. Despite changes in scope throughout the project, all schedules were met. Some unique features included multiple bores under active railroads and the jack and tunnel of a 12’x10’ concrete box culvert.

The project also included rehabilitating a failing 7’x7’ concrete box culvert by slip lining a 66” steel pipe and grouting the annular space.