Mining > Shaft Sinking > Shaft Boring

Shaft Boring - The V-Mole Method

RUC Cementation Mining Contractors is also able to provide access to the Wirth GSB-V 450/500 Vertical Shaft Boring machine (V-Mole), capable of reaming shafts with a diameter of up to 8.5m from a cetre core pilot hole.

The shaft boring machine, constructed similarly to a tunnel boring machine (TBM), widens the centre core pilot hole to the final diameter by reaming downwards. Reaming, much disposal, shaft support and permanent shaft equipping are performed continuously and concurrrently.

The steering system of the machine garantees the verticality of the bored shaft with the aid of a laser beam through the centreline of the shaft. The boring diameter can be varied within a range of 5.0 to 8.5m. The depth to be bored is not restricted by the shaft boring machine parameters, but becomes a factor of the ability to drill and ream a pilot hole to 1.83m in diameter. We know that the drilling of holes of 1,300 metres in length is possible and has been done before. The next challenge will be to drill a 1.83m diameter hole over a continuous length of more than 1,300 metres. The shaft depth is therefore unlimited as long as a centre core pilot hole is available.

A V-Mole shaft construction is carried out in various stages: -

• The raise drilling of a pilot hole and centre core to serve as a rock pass
• The construction of a pre-sunk fore shaft to facilitate the installation of the V-Mole machine
• The installation of the necessary and required hoisting facilities
• V-Mole boring, shaft support and equipping
• The final removal of the V-Mole at shaft bottom
• The commissioning of the permanent shaft system

 

RUC Cementation Mining Contractors strives to ensure that the correct equipment and people are provided for the job 

 

This method of shaft sinking was successfully employed by Murray & Roberts RUC in a second joint venture project with Thyssen Schachtbau to construct ventilation shaft No. 5 in the south fields of Pasminco Mining in Broken Hill, Australia. In the course of the sinking of the 810 meter deep shaft with a diameter of 6.5 metres, steep rock formations of amphibolites with a compressive strength of 350Mpa and gneiss with approximately 150Mpa were penetrated. After these two remarkable projects the following conclusions could be made:-

• Shafts could be completed on schedule
• Performance of up to 18 m/day (Oryx project - first joint venture) and 12 m/day (Pasminco) concrete lined shaft could be achieved with an average performance of 7.6 m/day
• The concrete support drilling and installation as well as concrete lining, could be done undisturbed
• During the course of shaft boring, the necessary injections could be performed to seal off the fissure water inflows
• A number of intermediate stations were excavated during the sinking process

RUC's ability to deploy a broad range of shaft sinking equipment provides the resources and people you need for any vertical development project with the highest regard for safety and environmental issues.

 

©2009 RUC Cementation Mining Contractors
Valid XHTML & CSS
Website Terms of Use