24-MMP-A5 Surface Mining Methods and Design · December 2018
Question 18 of 27
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Notes on this paper
Paper: Surface Mining Methods and Design (09-MMP-A5), National Exam, December 2018 — 20 pages, compulsory Question 1 (40 marks, parts 1.1–1.8) plus THREE of five optional Questions 2–6 (20 marks each) normally constitute a complete paper. As a study resource, this solution answers Question 1 in full AND all five optional Questions 2–6.
Reference texts: Hustrulid, Kuchta & Martin, Open Pit Mine Planning and Design (3rd ed.) — truck-shovel match factor, dragline stripping geometry, capital cost indexes, open-pit scheduling; SME Mining Engineering Handbook (3rd ed.) — equipment costing, mine dewatering, cost-index escalation.
Approach. Compare each computed requirement from 3.8 against the machine’s own rated capability from the Given specifications (Q3.4).
Digging depth check. Required overburden cut depth 25 m vs. rated digging depth 35 m: $$25\text{ m} \le 35\text{ m} \;\Rightarrow\; \text{OK, 10 m margin}$$
Stacking height check. Required operational stacking height 6.85 m (3.8.4) vs. rated stacking height 12 m: $$6.85\text{ m} \le 12\text{ m} \;\Rightarrow\; \text{OK, 5.15 m margin}$$
Reach check. Required dumping reach for the spoil pile (75 m, Q3.4) is well within the 90 m operating radius, and the digging reach across the 40 m pit (well under the radius) is not limiting either.
$$\boxed{\text{Yes} \text{ — the dragline can complete this cut without modification}}$$ all three governing limits (digging depth, stacking height, reach) clear with comfortable margin under the stated specifications.
Check
Required
Rated
Result
Digging depth
25 m
35 m
OK
Stacking height
6.85 m
12 m
OK
Reach (stacking/dig)
75 m / <55 m
90 m
OK
Check — this feasibility conclusion follows from the isosceles free-standing spoil-pile model stated in Question 3.8. A less favourable spoil geometry (e.g. one face vertical against prior spoil rather than at repose angle both sides) would give a taller, narrower pile and could erode or eliminate the stacking-height margin — worth re-checking once field survey confirms actual spoil-pile shape.
