kirra-docs

Design Underground Rings and Drives on a Section Plane

Underground design in Kirra is design on a section. You take a section across the drive, make it the plane the tools work in, and then draw, offset, triangulate and set out holes on it the way you would in plan. This page walks through a development round on a drive face and an uphole production ring above the drive, charged and checked.

Left: a development round drilled into the face (green). Right: an uphole ring collared on the drive back and fanned up to a target surface (red).

Kirra does not have a ring generator or a face (burn-cut) generator yet. You set the holes out with the drawing and hole tools below, and edit them in Edit Hole. Sections are not saved either: Kirra remembers the thickness, step, rotation and clip settings, but not the section line, and Draw on plane is off at the start of every session.

Before you start

The drive, as surfaces or as KAD lines you will draw — at least the profile where the face or ring sits.
For a ring, the level or surface the toes reach, such as the stope back or a target surface.
The 3D view. A section is a 3D view; the Section Plane switches to it for you.

1. Take the section and work on it

The Section Plane dialog with Draw on plane ticked and the WORK PLANE ACTIVE warning

Click Section Plane on the Select toolbar.
Tick Enable Section Plane.
Set Plane to Two Points and click two points across the drive where the face or the ring is to be. The view turns to look along the drive at the section. Segment does the same from a line you have already drawn.
Tick Draw on plane. The warning WORK PLANE ACTIVE appears across the top of the dialog: from now on drawing, offset, extend, triangulation and hole set-out work in the section, not in plan.
Tick Show Section Plane for a grid on the section. The grid spacing is the Step Increment.
Set the slice. Look Forward and See Behind of 1 show just the face; 20 shows a whole ring fan, as in step 4.

Looking along the drive at a face round, with the Section Plane dialog set to Two Points and Draw on plane Looking along the drive at the face: perimeter holes 1–24, lifters L1–L7, and the cut in the middle.

To move to the next face or ring, step the section with the double-chevron buttons beside Position, or Page Up / Page Down. The full list of controls is in Section Views.

2. Draw the drive profile on the section

With Draw on plane ticked, KAD points, lines and polygons land on the section instead of in plan — see Drawing Tools.

Profile. Draw the drive outline as a KAD polygon or line on the section.
Rows inside the profile. Offset works in the section: offset the profile inwards for the perimeter, easer and other rows. Each offset is a new line you can set holes out along.
A face or back surface. Triangulate gains a Triangulate In field: choose Section plane to build a surface across the face. A face or a wall works; a whole tunnel does not.

3. Set out a development round on the face

Holes Along Polyline set out on a perimeter line drawn on the face The perimeter line picked from START to END on the face, ready to set out holes along it.

Holes Along Polyline is the tool that sets holes out in the section: collars along the line, drilled into the face.

With the section set up as in step 1, click Holes Along PolyLine on the Holes toolbar.
Click the line — for example the perimeter offset.
Click the vertex where the holes start, then the vertex where they end. The canvas labels them START and END, and the Generate Holes Along Polyline dialog opens.
Fill in the dialog and click OK.

The Generate Holes Along Polyline dialog filled in for perimeter holes on a face

On a section, some fields mean something different from plan:

Field	On a section
Collar Elevation (m)	Ignored. The collars sit on the section, on the line you picked
Hole Angle (° from vertical)	The angle off square to the face. 0 drills straight into the face; a few degrees gives look-out. See Known issues
Length (m)	How far the holes drill into the face
Bearings are 90° to Segment	Each hole is set square to its own segment of the line
Spacing (m)	Distance between collars, measured along the line
Hole Type	Name the row, for example Easer, Lifter or Cut

Run it once for each row line to build up the round: perimeter, easers, lifters, then the cut.

Face holes are Non X-Y holes

Holes set out this way are Non X-Y holes: Kirra measures them against the section (their Design Plane), not against plan. In Edit Hole, the Properties tab shows plane fields in place of the plan ones.

Edit Hole Properties for face holes, showing Plane Bearing, Plane Angle, Plane Subdrill and Plane Bench

Field	Measured
Plane Angle (°)	From the Design Plane’s normal: 0 = square into the plane. Change the look-out here after the holes are made
Plane Bearing (°)	Around the normal, looking into the plane: 0° = up, 90° = right, 180° = down, 270° = left
Plane Subdrill (m)	Drilled past the design depth, along the normal
Plane Bench (m)	Depth from the collar to the grade, along the normal
Collar Z RL (m)	The collar’s elevation

Add Hole, Add Pattern, Pattern in Polygon and Holes Along Line also click on the section, but they drill by plan angle and bearing. To turn holes made with them into face holes, select them, open Edit Hole, and on the Additional tab set Design Plane to Non X-Y hole — active section plane. It needs Draw on plane ticked. Insert Holes continues a row of face holes in their Design Plane.

4. Design an uphole ring

An uphole is an ordinary hole with a negative Dip/Angle and a negative Hole Length. The toe is above the collar. Negate both: a negative angle with a positive length — or the other way round — drills the hole the opposite way to its bearing.

Edit Hole for an uphole ring hole: Hole Length -25.18, Bearing -40, Dip/Angle -30, Grade Z RL 110 Ring hole 1: Dip/Angle −30, Hole Length −25.18, collar at RL 88.20, toe at RL 110.00.

Draw a collar line along the arch of the drive back, on the section.
Set the collars out along it with Holes Along PolyLine, as in step 3. Its dialog only takes a positive angle and length, so the holes come out drilling down for now.
Select the holes of a row, right-click one, and in Edit Hole set:
- Dip/Angle (°) — negative. −30 is 30° off vertical, upward.
- Hole Length (m) — negative.
- Bearing (°) — fan the holes across the ring, for example from −40 to 40.
- Grade Z RL (m) — the level the toes reach, for example 110.
Repeat for the next row with its own angle. The example ring tilts its rows at −30, −20, −10 and −5.

Edit Hole takes calculations for a whole selection: type =+0.3 to add or =-0.2 to subtract from each hole’s value — see Editing Holes.

If you place a single uphole with Add Hole instead, leave Use Grade Z unticked and type the negative Dip/Angle and Length yourself. With Use Grade Z ticked, Kirra works the length out as a positive number, and the hole drills the opposite way.

5. Show the markers square to the hole

In plan, the collar, grade and toe markers and the hole text lie flat. For face holes and upholes, turn them square to the hole so they read along the section.

Face holes with their markers turned square to each hole, and the Edit Hole Additional tab set to Hole Track

Select the holes and right-click one to open Edit Hole.
On the Additional tab, set Marker Alignment (3D) to Hole Track.
Click Apply.

Plan puts them back flat.

6. Charge the upholes

Charge upholes in the Deck Builder or on the Loading tab of Edit Hole, the same as any hole. Deck depths are metres from the collar for every hole — for an uphole the collar is the low end, at the drive.

The Loading tab for an uphole: air from the collar to 4.1 m, BLOWANFO from 4.1 m to the toe at 10.2 m, primer at 9.2 m

The Loading diagram always draws COLLAR at the top, even for an uphole. Read it from the collar: in this hole the first 4.1 m above the drive is air, and the BLOWANFO runs from 4.1 m up to the toe, with the primer at 9.2 m near the toe. The uncharged collar length is reported as Stemming.

The ring seen along the section, with the air collars in cyan and the explosive in magenta The charged ring seen along the section: uncharged collars at the drive, explosive towards the toes.

7. Blast volume and powder factor

Kirra works out a volume for every blast, so you do not need a solid to design or charge a ring. But a fan’s volume is not burden × spacing × hole length, so to report the ring’s volume and powder factor correctly, give it a closed solid:

Build the solid with the surface tools — Extrude KAD to Solid, Triangulate and the Booleans. The example ring’s solid is two surfaces joined with a union, with the sides then connected by hand.
In the Data Explorer, right-click the ring’s blast and choose Assign Volume….
Choose Created solid (select below) and pick the solid.

The blast’s volume and powder factor then come from the solid — see Statistics. For a fan, report the blast powder factor; per-hole powder factors are estimates.

8. Check the design

Step through it. Step the section along the drive with Page Up / Page Down and look at each ring or face in turn. Widen Look Forward and See Behind to see a whole ring.
Check the toes. In the example, the centre hole of each row stops at RL 100 while the rest reach RL 110, leaving a gap at the top of the ring. A section along the ring shows it straight away.
Coverage. The Analyse toolbar shaders show the explosive distribution through the ring.

Known issues

Issue	What to do
Hole Angle (° from vertical) in Holes Along Polyline reads “from vertical”, but on a section the angle is from square to the face. Kirra treats the section as if it were plan	Read it as “off square to the face”: 0 drills straight in
Collar Elevation (m) in Holes Along Polyline does nothing on a section	Ignore it — the collars sit on the line you picked
On the Additional tab of Edit Hole, the Design Plane (now Non X-Y) label runs into its list	The list still works
The section line is not saved	Take the section again each session — Two Points across the drive at the same place
No export for underground drill rigs yet	See below

Exporting to an underground drill rig

Kirra has no export written for underground drill rigs or systems yet. Each one needs a real example of the file the rig or system reads — IREDES, an XML or anything else — to build and check against, and none has been provided so far. If you have one you can share, send it to blastingapps.xyz@gmail.com with the rig or system it is for.

Section Views — every Section Plane control
Holes Along Polyline
Editing Holes
Offset and Triangulate on a section
Deck Builder