ACALA

Geological Expertise, Mining Excellence

Underground Mine Design and Planning · Engineering and operations expertise

Underground mine design and planning: the right method, a robust plan, and capital spent where the orebody rewards it.

ACALA brings extensive expertise in underground mine engineering and operations across commodities and mining methods. Our rigorous approach maximises the economic potential of your project by placing the deposit in its broader mining context, guiding method selection and building a future-ready plan that cuts capital and operating cost in downturns and scales capacity when the market improves, with highly mechanised and automated solutions on industry-leading software.

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See the services offered
Open pit to underground transition: cost per tonne of ore for a deepening pit against an underground alternative, at the chosen pit depth $ / t ore 100 m500 m depth — open pit (stripping grows) – – underground pit depth 250 m · strip ratio 10 · open pit 33 $/t vs underground 45 $/t · stay open pit
Illustrative transition analysis: as the pit deepens, stripping pushes the cost per tonne of ore towards the underground alternative. The crossover is where the transition study starts, not where it ends. Drag the handle from 100 to 500 m.
Method selectionStoping, caving or room and pillar, chosen from the orebody, not from habit.
Ground supportGeotechnical characterisation and support systems designed for the rock you have.
VentilationAirflow modelled and designed for the development and production you plan.
Life-of-mine planDevelopment and stoping sequenced for maximum resource use.
Mechanised and automatedHighly mechanised solutions on industry-leading software.
TransitionWhen and where the open pit should hand over to underground.
ACALA's Principal Mining Engineer discussing with underground mining engineers at the face
ACALA’s Principal Mining Engineer in discussion with the mine’s underground engineers at the face.

Why ACALA

Designs and schedules that allocate mine capital and resources efficiently.

Our team understands the need for continuous adaptation to fluctuations in commodity prices and operating costs. We help operations respond: reducing capital and operating expenses during downturns while scaling capacity when market conditions improve.

Geometry, grade distribution, geotechnics and infrastructure feeding method selection and mine layout, which is only then optimisedTHE ORDER THAT MAKES A PLAN ROBUSTgeometrygrade distributiongeotechnicsinfrastructuremethod selectionand mine layoutthen optimisedrobust before it is optimised

The deposit in its context

Method selection and mine layout follow from geometry, grade distribution, geotechnics and infrastructure, so the plan is robust before it is optimised.

Development, stopes, ventilation and services designed as one, then scheduled in MineSched as two bar rows in which each development bar leads the stope it opensDESIGNED TOGETHER, THEN SCHEDULEDdevelopmentstopesventilationservicesMineScheddevelopmentstope productiondevelopment always ahead of the stope it opens

Practical designs, practical schedules

Development, stopes, ventilation and services designed together, then scheduled in MineSched so development advance and stope production stay in step.

A mechanised equipment set feeding the Stope Shape Optimizer, which turns a ragged stope outline into a clean one, feeding a first-principles cost stack and then the capital decisionFROM STOPE SHAPE TO CAPITAL DECISIONmechanised + automatedStope Shape Optimizercost modelcapitaldecisioneach layout costed item by item, then decided

Technology where it pays

Highly mechanised and automated solutions, Stope Shape Optimizer for stope layouts, first-principles cost models for the capital decision.

ACALA services offered

Eleven services from the first study to operational assistance.

  1. 1

    Engineering studies

    Comprehensive evaluations across all project stages for effective underground operations.

  2. 2

    Strategic planning

    Optimisation of economic cut-off grades and production rates.

  3. 3

    Geotechnical characterisation

    Advanced ground support system design and analysis for underground settings.

  4. 4

    Life-of-mine plan optimisation

    Long-term strategic planning for maximum resource utilisation.

  5. 5

    Drill and blast design

    Fragmentation analysis for improved efficiency and cost control.

  6. 6

    Ventilation system modelling and design

    Optimised airflow solutions for underground environments.

  7. 7

    Equipment and manpower estimation

    Detailed assessments to support operational planning.

  8. 8

    Cost benchmarking and modelling

    Operating and capital expenditure evaluations using first-principles cost modelling.

  9. 9

    Open pit to underground transition analysis

    Expert guidance for seamless mine conversions.

  10. 10

    Due diligence reviews

    Comprehensive assessments to support investment and operational decision-making.

  11. 11

    Operational reviews and assistance

    Strategic consulting to enhance mine performance.

Underground mine engineering solutions
Underground engineering: development, stopes and services designed together.
Underground mine design and schedules
Designs and schedules that maximise efficiency, capital use and resource value.

Tools and training

Designed in the software your planners already run, and taught to them afterwards.

Underground designs in GEOVIA Surpac, stope layouts from Stope Shape Optimizer, schedules in MineSched. Deliverables stay usable in your office, and ACALA’s certified instructors train your team on the same files.

Reading

Articles on grade control, dilution and planning

Questions we get

Underground design FAQ

How do you choose the mining method?
From the orebody geometry, grade distribution, rock mass quality and infrastructure, evaluated against candidate methods on cost, recovery, dilution and safety. The choice is documented so it can be revisited as the deposit is better known.
When should an open pit go underground?
When the cost of stripping the next pushback exceeds the cost of mining the same ore from underground, allowing for capital, development lead time and the value of the remaining pit. The transition analysis compares both on the same block model.
Do you cover ventilation and ground support?
Yes. Geotechnical characterisation with ground support design, and ventilation system modelling and design, are part of the service alongside the mine plan.
Which software do you deliver in?
GEOVIA Surpac for design, Stope Shape Optimizer for stope layouts and MineSched for schedules, so your own planners can keep working on the files.
Can you help an operating mine, not just a study?
Yes. Operational reviews and assistance, equipment and manpower estimation and cost benchmarking are offered to operating mines that want to improve performance.

Next step

Your project deserves clarity and confidence. Let us look at the orebody with you.

Tell us the deposit, the method you have in mind and the decision you face. A mining engineer replies with a scope, data request and schedule.

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Use the contact form
Bekasi, Indonesia
+62 21 8066 9600
office@acala.co.id
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