OPEN PIT DESIGN
STREAM's Pit Planning module is open pit design software that builds the whole pit in one editor: benches from a template, wall angles by geotechnical sector, haul ramps solved against the benches with cycle time and cost, volume and tonnage per bench, push-back phases and a period-by-period production schedule. It sits on the surveyed terrain already in your project, checks its own geometry, and writes DXF, LandXML, CSV and a PDF report — on your own Windows machine, offline.
Open pit design software turns a mining limit into a buildable pit: a stack of benches with a height, a berm width and a face angle; walls that steepen or flatten by geotechnical sector; a floor wide enough for the loading equipment; and a haul ramp that actually reaches every bench at a grade a loaded truck can climb. The design is judged by three angles — the bench face angle (BFA), the inter-ramp angle (IRA) and the overall slope angle (OSA) — and by what it costs to haul the rock out.
STREAM's Pit Planning module (DESIGN ▸ Surface Design ▸ Pit Planning) is that editor. It has nine tabs — Template, Sector, Floor, Haulage, Bench Plan, Section, Volumes, Schedule and Check — and every number in it is derived from the boundary you select, the template you set and the terrain in the project. The pit is drawn as crest and toe rings in a 2D plan beside the 3D view, and corners can be dragged in either.
It is a design and volume tool, not a resource model and not a slope-stability solver. Ore, waste and grade come from a block model you import; the angle limits per sector are inputs you take from the geotechnical report. What STREAM does is hold the geometry to those limits and tell you where it cannot.
Bench height, berm width and face angle make the template (defaults 10 m, 6.5 m, 70°). STREAM reports the Modified Ritchie berm (0.2·H + 4.5 m), the inter-ramp angle, the slope run H/tan(face) and the horizontal step per bench, and can widen every Nth berm as a safety catch berm. Any bench may override the template; templates are kept in a library on your machine.
A sector rose divides the pit by azimuth; each sector carries its own face angle, berm, IRA limit, OSA limit and stack-height limit. Domain angles and elevation-band or area rules add exceptions. A back-break mean and standard deviation give a Ryan–Pryor catch-bench reliability checked against a target, and a regulatory minimum berm can override the criterion. The sector table can be built from the domain field of a block model.
The floor is measured by the largest circle that fits inside it — not by area — and compared with the minimum mining width derived from shovel swing, truck turning and a safety clearance. Bench elevations can snap to a grid so crests and floors land on round levels, and the pit can be deepened down to the terrain. Dilution, ore loss and cut-off thresholds shape the tonnage reported later.
Ramps are main, secondary, service, connector, temporary or flat, with start and end bench, entry station, target grade, total width and turning circle. The road class follows truck width (2.5× one-way, 3.5× two-way, 4× on curves) and the minimum turning radius is 1.5× the truck's turning circle, after Kaufman and Ault. Switchbacks, flat runs, grade and width exceptions, passing bays and intersections are set per bench; the road notches into the benches or the berm widens to make room, box-cut or adaptive at the wall.
From truck width, length, body volume, rolling resistance and the load, dump and queue times STREAM computes the haul cycle for every bench depth, cycles per hour, tonnes per hour, shift production and tyre TKPH. Optional rimpull and retarder curves with vehicle mass make the speed power-limited. Fuel, tyre, maintenance and operator rates give cost per tonne, per tonne-kilometre and the life-of-pit haul cost by period.
Each bench volume is the frustum between its crest and toe areas, V = H/3·(A₁ + A₂ + √(A₁A₂)); the total is verified by an independent triangle integral of the design surface. With a density the table adds tonnage; with an imported block model it adds ore, waste, grade, cut-off and the strip ratio. Swell gives the loose volume for haulage. Unmeasured cells stay blank — never zero.
Branch a bench chain into a second arm to design a push-back on the same floor; phases are computed as inward steps with their own dig, ore and waste. A waste dump is sized by lift height, angle and berms against what the pit produces; a pit sump against catchment, design rainfall and pump rate; closure cover against a thickness and a slope; in-pit backfill and a cone or ridge stockpile against a fill level.
A rule — deepest first, surface first, smallest job first or topological — fills a Gantt of benches by period from the fleet you define: trucks, shift length, shifts per day, efficiency, maintenance. Capacity falls as the ramp lengthens. Period targets, the shift pattern and dig constraints are checked. The Check tab lists every finding with its remedy across topology, geometry, constraint, sector and ramp gates, and scenarios can be copied, compared and ranked.
Open DESIGN ▸ Surface Design ▸ Pit Planning and pick a closed area from the project as the pit limit (crest), or draw one. Anchoring at the floor builds the pit upward instead.
Enter bench height, berm width and face angle. Read the Ritchie berm, the inter-ramp angle and the spread for 100 m of depth, then add benches below — each new bench starts from the template.
Turn on sector solving, split the rose by azimuth and enter each wall's angles and limits from the geotechnical report — or build the table from the block model's domains.
Enter shovel swing, truck turning and safety clearance. The Floor tab shows the inscribed circle of every floor piece against the minimum mining width.
Add a ramp, choose its type and entry side, set the target grade and width, and solve. The plan shows the achieved grade, length, tightest turn and which benches are still not reachable.
Enter density and swell; import the block model for ore and waste. The Haulage tab gives cycle time and cost per tonne for every bench depth.
Define the fleet and the periods, pick a rule and read the Gantt. Clear every finding in Check, approve the revision, and export DXF, LandXML, CSV and the PDF report.
| Tab | What it holds | Key outputs |
|---|---|---|
| Template | Bench height, berm, face angle, safety-berm interval, corner rounding | Ritchie berm, IRA, slope run, spread per 100 m of depth |
| Sector | Azimuth sectors, domain angles, rules, limits, reliability | Steepest and flattest wall, design IRA range |
| Floor | Anchor elevation, floor pieces, equipment sizes, dilution, cut-off | Inscribed circle vs minimum mining width, mesh topology |
| Haulage | Ramp table, truck data, times, costs, rimpull | Cycle time, t/h, TKPH, cost per tonne by depth |
| Bench Plan | Bench table, branches, splits, no-dig zones, ramp design | BFA, IRA, OSA, depth, floor area |
| Section | An A–A′ line through the pit | OSA per wall, span split between rock and road |
| Volumes | Density, swell, phases, dump, water, closure, as-built | Frustum volumes, tonnage, strip ratio, exports |
| Schedule | Rule, fleet, periods, targets, shift pattern, constraints | Gantt, capacity vs ramp length, binding constraint |
| Check | Gates and findings | Remedies, scenario comparison and ranking |
Software that builds a pit from a mining limit: benches with height, berm and face angle, walls by geotechnical sector, a floor wide enough for the equipment, and haul ramps that reach every bench. It reports the bench face, inter-ramp and overall slope angles, the volume and tonnage per bench, and what the haul costs. STREAM's Pit Planning module does this on the surveyed terrain already in your project.
No. Ore, waste, grade and cut-off come from a block model you import; STREAM cuts that model against the benches and reports the result. It does not run grade estimation or an economic pit-limit optimisation. The pit shape is yours: template, sectors, ramps and phases.
No. The face angle, inter-ramp and overall slope limits per sector are inputs you take from the geotechnical report. STREAM holds the design to those limits, reports the measured angles beside them, and flags every sector where the design or the measurement exceeds a limit.
As a frustum between the crest and toe areas of the bench: V = H/3·(A₁ + A₂ + √(A₁A₂)). The total is checked a second way by integrating the triangles of the design surface, and the difference is reported. With a density you get tonnage; with swell, the loose volume.
The bench face angle (BFA) is the angle of a single bench face. The inter-ramp angle (IRA) is the angle of a stack of benches between ramps, crest to crest, flattened by the berms. The overall slope angle (OSA) runs from the top crest to the bottom toe of the whole wall and is flattened further by the ramps. STREAM reports all three and, on a section, shows how much of the horizontal span is rock and how much is road.
You give the ramp a type, start and end bench, entry side, target grade and total width; STREAM solves it against the bench rings and reports the achieved grade, length, elevation dropped and the tightest turn. Road width classes follow the truck width and the minimum turning radius is 1.5× the truck's turning circle. Switchbacks, flat runs, passing bays and grade exceptions are added per bench.
Truck width, vehicle length, body volume, surface haul distance, speed limits, rolling resistance and the load, dump and queue times. For a power-limited speed add engine power, empty and loaded mass, and rimpull and retarder curves from CSV. Cost per tonne then follows from fuel, tyre, maintenance and operator rates.
Yes. A bench chain can branch into a second arm from any bench — the same floor with two wall designs — and phases are computed as inward steps with their own dig, ore, waste and grade. Merging two arms is refused if their elevations or directions do not match.
By a rule — deepest first, surface first, smallest job first or topological order — applied to the benches with the fleet's capacity per period. Capacity falls as the ramp lengthens, so the schedule is bound to the ramp design. Targets per period, a shift pattern and dig constraints are checked, and the binding constraint is named. It is a rule-based schedule, not an optimiser.
DXF for the plan, the section and the design surface as 3DFACE; LandXML for the surface and the main ramp alignment; OBJ; CSV for volumes, schedule, deviation and the audit trail; a PDF Pit Planning Report; and the plan as JSON. The pit can also be written to the project as crest and toe layers, or applied to the terrain as a patch.
Yes. The anchor elevation is read from the terrain along the boundary, the pit can be deepened down to the terrain, and Apply to Terrain writes the design surface into the DEM as a patch that a second click removes. As-built reconciliation samples today's surface at every design node and reports over-break, under-break and the deepest deviation.
Yes. Copy the current pit as a scenario, change it, and the Check tab compares the two — volume, tonnage, depth, overall slope, road length, findings — with a structural diff of what was added or changed. Scenarios can be ranked by any of those measures.
Free beta for Windows x64. Works fully offline with GeoTIFF, LAS/LAZ and DXF.
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