Large Diameter

15 Mile Sink Hole

10 ft. Diameter X 70' Deep

Cored through existing 11ft. diameter tunnel.

This allowed for temporary pumping of sewage to ground level around the collapsed portion of tunnel.

Used to construct a semi-tangent wall.

This included placing an I-beam in the center for rigidity and allowing the internal bracing support.

Once the necessary bracings were installed, the tunneling contractor open cut down to the tunnel for repair.