Location: Milwaukee, WI
Owner: Milwaukee Metro. Sewerage District
Completed: December 2009
This project included installation of 4,200 lineal feet of 48” RCP and 6,089 lineal feet of 72” RCP all via slurry pressurized face microtunneling. There was an array of different soil conditions on this project ranging from full face of rock to dense clays to saturated sands on silts, to zero blow count organic soils. The longest drive on the project was 1,068 lineal feet. The project also contained a total of 18 construction shafts ranging in depth between 30 to 80 vertical feet. Shaft construction varied based on soil conditions – in areas of high water table and poor soils (organics and saturated silts) we use interlocked steel sheeting and grouted the tunnel eyes to eliminate settlement, and in areas where we had stiff clays, the shafts were constructed with steel ribs and wood lagging. The entire project was located in the near South side of the City of Milwaukee and had very narrow city streets. Equipment setups required very tight configurations in order to accommodate traffic and pedestrian access.