|Subcontractors begin excavating the access tunnel to the future NOvA Near-Detector Hall. Photo: Cindy Arnold|
With the site preparation and utility relocation phase of the construction of the NOvA Near-Detector Hall nearly complete, subcontractor Kiewit Infrastructure Co. has recently begun the excavation phase.
Kiewit workers have removed the protective layer of shotcrete and mesh from the area that will be mined to create an access tunnel to the new hall. The tick marks identify the areas where rock bolts will be installed to strengthen the rock mass between the existing tunnel and new hall.
The picture shows the first of two entrances that will be dug out. The subcontractor will excavate a second entrance to the right of the one pictured.
The hall will be located just upstream (closer to the proton source) of the MINOS near detector and the MINERvA detector in the NuMI tunnel.