Shaft Lining with Shotcrete

The rig comprises of three cameras and three lights for viewing and recording the shaft, a hydraulic motor to drive the rotation of the nozzle and an integral water dosing housing. The rig is fitted with Mines Department Approved enclosures and lighting so it can be utilised in coal mine applications.

Outside the shaft there is a control room that houses the water, hydraulic, electrical and monitoring controls. A dry mix concrete pump is located near the shaft where an agitator discharges its load. Jetcrete currently has 3 units in operation.

The Monitoring equipment and dry shotcrete and hydraulic packs etc are set-up away from the shaft collar, handrails and or barricades with signage are erected in the appropriate areas before the application of the shotcrete can be commenced the application can be monitored and recorded through CCTV.

Once the module and umbilicals have been assembled on the ground, the crane or winch can lower the module into the shaft to the section that needs to be sprayed.

Accurate Depth Measurement

An attachment to the system is the rope measurement device that is installed on the crane or winch that accurately depicts the depth of the rig in the shaft. This allows for accurate cover of an area that helps with recording of data and when used with the table (over page) gives an accurate thickness of lining. The measurement is also recorded onto any video taken of the shaft.

Thickness Control

In the early stages of the lining an object of a known thickness is lowered in shaft and sprayed over by shotcrete to determine what thickness is actually being applied with each revolution of the spray head. The numbers of passes to cover this are recorded and used to calculate the cubic metres.

Operation

The Spray rig is lowered into the shaft.

On dissention the client can be shown areas that are or have been sprayed for visual approval.
The umbilical are lowered or lifted with the module have to attain the same lowering speed that the crane/ winch is at to avoid any damage that may be caused due to stretching.

At the desired top level the application can be commenced.

For the last 9 years Jetcrete has been developing a remote shaft lining system that has eliminated the need for man riding in shafts requiring the application of shotcrete.