slip volume not very material it seems, page-103

Plough extract from RED 5 website below; note the words dewatering strategy is paramount to success!!! Pit angles at 32 to 40 degrees well below angle of repose; however when the pit walls are saturated all bets are off. How can they write this stuff and apparently not follow there own strategies? Purely amazing seeing as they budgeted $2.4M for pit de-watering in the 2013 SPP.


"Significant features of the open pit are geotechnical and hydrological features. The host rocks are permeable and in places rich in clay. For this reason ground water from rainfall around the mine reports to the open pit readily. The mine can see up to 700 l/second of water inflow in peak periods. This means the mines dewatering strategy is paramount to success.

A fence comprising some 8 dewatering bores is now installed around the pit perimeter to combat water inflows allowing the water table to be maintained below the pit bottom thus creating a dry working environment. Utilising dewatering bores has the added benefit of keeping the walls of the pit dry which aids wall stability, as well as, minimising the requirement for settling of water to remove sediment prior to discharge into the surrounding rivers. The SIANA open pit walls are relatively shallow at between 32 and 40 degrees as an overall slope angle. Constant monitoring of the walls ensures the safety of all employees."

Ref
http://www.red5limited.com/projects/siana-gold-project.html#Mining