2009/2010 Stage 2 Problem Statement - SME

2009-2010 SME/NSSGA Student Design Competition
2.6. Questions to Address
During the last meeting with your engineering department, the following questions were raised.
Your team needs to answer as many of them as possible before the board of directors meeting.
1. What are the safe slope angles for the pit slope walls? Disregard any weathered rock or
soil at the surface for this exercise.
2. What percent rock fall catchment is expected for the 25-foot safety benches and is this
catchment acceptable during the mining? Risk cannot be eliminated, but as a mining
engineer, your job is to assist in establishing the risk that your company is willing to
accept while the ultimate decision will be made by management and any stakeholders.
3. If presplit blasting was used to excavate the pit slope walls, or there was a contingency
for detailed bench geological mapping and reinforcement of potential structural failures
during mining, would that make a difference in the amount of aggregate available for
mining? What would be acceptable pit slope inclinations if presplit blasting was chosen
over production blasting for the final walls and what would be the increase in volume of
aggregate available for mining?
4. In general terms, how would you establish the savings or loss of revenue associated with
pre-split blasting and/or reinforcing unstable rock blocks within benches of the highwall
with regards to the amount of minable aggregate available while maintaining the safety
factor required for this quarry?
5. Do you think that there is value in collecting additional geotechnical data and how would
the additional data be used to more accurately establish the pit wall inclinations?
8