SEI crews have successfully lowered the 102-inch Lovat TBM cutterhead into the shaft for tunneling operations on the South Interceptor Forcemain Project for the City of Omaha. The TBM is scheduled to launch in mid-September.
The project comprises 2,480 lf of 72-in. ID rock tunnel using conventional tunneling methods, with ring and beam lagging, at approximately 100 vf; completion of two working shaft for the rock tunnel construction; construction of a 64-in. steel cased tunnel under UPRR tracks by auger bored tunnel method; and installation of two 84-in. steel casing tunnels under the UPRR Bridge embankment. Aside from tunneling, the project also includes: the installation of 42-and 48-in. restrained joint force main installed by open-cut methods and supported on piles; construction of a vault valve structure; blasting; vibration control and monitoring; and soil stabilization by jet grouting.
Super Excavators has completed construction of shafts including secant pile shafts using a Soilmec SR-90 drill rig; and drill and blasting work in limestone rock (with rock bolt anchors and mesh) to complete construction of the lower 35+ feet of the launch shaft which will be approximately 75-feet deep (the 38-foot overburden was constructed with 38-inch diameter secants). The first section of deep open cut work is also now complete.
This project is scheduled for completion 4th quarter of 2016.