BORTECH HORIZONTAL DTH HAMMER METHOD
"Bortech's DTH Horizontal Hammer System completed several of our water utility tunnels. There system was the only method that could drill through 50,000 psi volcanic basalt rock formation"
NJAW-Senior Project Engineer
BASKING RIDGE, NJ 2020
Bortech was called upon by a NJ based general contractor that was in the process of installing 130' of 24" steel casing pipe under a New Jersey Transit NJT commuter railroad line. The rock formation changed from a medium strength to a very hard volcanic gneiss Basalt formation. The crossing was attempted using disc cutter technology. Where the required thrust to penetrate this hard rock is too much for the capacity of the bearings. The contractor spent 6-weeks in the project and could not penetrate the rock.
Bortech employed their first build DTH Horizontal hammer system on this project. With this hard rock formation. The correct hammer size and air pressure would be necessary to fracture the rock and advance the casing pipe. Because the previous attempt deviated from the design line and grade. We moved the centerline of our drill over. We successfully completed the rock bore in 5 shifts. And recorded penetration rates of 10'-15' per hour.
Since this project Bortech has performed several bore project ranging from mixed face rock, boulders and cobbles as well as blasted rock fill zones under highways.