Blacksnake Creek Stormwater Separation Improvement Project
The Blacksnake Creek Stormwater Separation Improvement Project was designed to intercept and convey the Blacksnake Creek flows as well as other stormwater flows that are currently directed into the Blacksnake Creek Basin combined sewer system. The Work generally consists of the construction of 108-inch diameter concrete precast segment lined 6,648-foot long tunnel constructed by EPB TBM; launch shaft; receiving shaft; 44 ID secant drop shaft with 60 VF depth; 48 feet of near surface reinforced concrete box culvert, 2-foot diameter vent shaft, 181 feet of 90-inch diameter open cut steel pipe installation, 125 feet of 90-inch jacked steel pipe beneath the BNSF railroad excavated by auger boring machine; an energy dissipation structure, site restoration, and performance of other associated works.
Ground conditions along the tunnel alignment transition from soft ground to hard rock with some mixed face conditions between. This project is utilizing the first China-Built Lovsuns TBM for the North American Market. The TBM arrived in the USA in June 2018 and was successfully assembled on site. Tunneling commenced in Spring 2019 and as of Early August 2019 the tunnel is about 75% complete.