kirra-docs

Pattern Generation

Kirra can automatically generate blast patterns in several geometric configurations. Pattern generation is the fastest way to lay out a new blast from scratch when you know your burden, spacing, and bench geometry.

Choosing a Pattern Method

Method Best For Menu Path
Rectangular Grid Standard bench blasting with uniform rows and columns Pattern > Add Pattern
Polygon Pattern Irregular blast boundaries, pit edges, complex shapes Pattern > Polygon Pattern
Line Pattern Single-row presplit, buffer, or production lines Pattern > Add Line
Polyline Pattern Curved or multi-segment rows following contours Pattern > Add Polyline

Screenshot coming soon

Rectangular Grid Pattern

Creates a regular grid of blast holes with uniform burden and spacing. This is the most common pattern type for bench blasting.

Menu: Pattern > Add Pattern

Parameters

Parameter Description Typical Value
Pattern Name Name for this group of holes Bench_150_North
Number of Rows Rows perpendicular to the free face 5 to 10
Number of Columns Holes per row, parallel to the free face 10 to 20
Burden Distance between rows (metres) 5.0 m
Spacing Distance between holes within a row (metres) 6.0 m
Collar Elevation Starting Z elevation for all holes (metres) 150.0 m
Bench Height Vertical distance from collar to grade (metres) 10.0 m
Subdrill Vertical distance below grade (metres, positive = downhole) 1.5 m
Hole Angle Angle from vertical (0 = vertical) 0 degrees
Hole Bearing Direction of hole angle (0 = North, clockwise) 0 degrees
Hole Diameter Diameter in millimetres 115 mm
Hole Type Classification Production
First Hole Position Easting and Northing of the pattern origin Site coordinates

Pattern Layout

Rows (Burden direction)
 |
 v
 *  *  *  *  *   <-- Row 1
 *  *  *  *  *   <-- Row 2
 *  *  *  *  *   <-- Row 3
    --> Spacing

Steps

  1. Go to Pattern > Add Pattern
  2. Enter the pattern name (e.g. Bench_150)
  3. Set the starting position (Easting, Northing, Elevation)
  4. Configure the number of rows and columns
  5. Set burden and spacing distances
  6. Enter hole specifications (bench height, subdrill, angle, bearing, diameter)
  7. Click Generate
  8. Holes appear immediately on the canvas

Hole Naming

Generated holes are numbered sequentially: H001, H002, H003, etc. Row-based naming is also available: R1-H01, R1-H02, R2-H01, etc.

Polygon Pattern

Fills an irregular polygon boundary with holes at the specified burden and spacing. Holes that fall outside the boundary are automatically excluded.

Menu: Pattern > Polygon Pattern

Steps

  1. Go to Pattern > Polygon Pattern
  2. Define the boundary by clicking points on the canvas to trace the polygon outline, then double-click to close it. Alternatively, select an existing polygon from a DXF import.
  3. Enter burden and spacing
  4. Set collar elevation and hole properties (bench height, subdrill, angle, bearing, diameter)
  5. Optionally enable stagger (offsets every second row by half the spacing)
  6. Click Preview to review before committing
  7. Click Generate — holes fill the polygon

Edge Handling

Use Cases

Screenshot coming soon

Line Pattern

Creates a single straight row of holes between two points.

Menu: Pattern > Add Line

Steps

  1. Go to Pattern > Add Line
  2. Define the start point and end point by clicking on the canvas or entering coordinates
  3. Enter the number of holes or the spacing between holes:
    • If you specify hole count, spacing is calculated automatically
    • If you specify spacing, hole count is calculated automatically
  4. Set hole properties (collar elevation, bench height, subdrill, angle, bearing, diameter, type)
  5. Click Generate

Pattern Layout

Start --> *  *  *  *  *  *  * <-- End
          |<-- Spacing -->|

Use Cases

Polyline Pattern

Creates a curved or multi-segment row of holes following a polyline path. This is ideal for contour-following patterns.

Menu: Pattern > Add Polyline

Steps

  1. Go to Pattern > Add Polyline
  2. Click multiple points on the canvas to define the path, or select an existing polyline
  3. Enter the hole spacing along the path (metres)
  4. Set hole properties (collar elevation, bench height, subdrill, angle, bearing, diameter, type)
  5. Click Generate

Pattern Layout

        *--*--*
       /       \
      *         *--*--*
     /               \
    *                 *

Bearing Options

Option Description
Follow Path Each hole is angled perpendicular to its local path segment
Fixed Bearing All holes use the same bearing regardless of path direction

Use Cases

Screenshot coming soon

Collar Elevation Options

When generating any pattern type, you can set collar elevations in several ways:

Mode Description
Constant Elevation All holes use the same Z value that you enter
From Surface Collar Z is interpolated from a loaded terrain surface at each hole’s Easting/Northing position
From Grade + Bench Collar Z is calculated as Grade Elevation + Bench Height

Using the From Surface mode enables adaptive patterns that follow terrain topography.

Common Settings for All Patterns

All pattern types share these hole-level settings:

Setting Description
Default Depth / Bench Height Vertical bench height (metres)
Default Subdrill Subdrill below grade (metres)
Default Diameter Hole diameter (mm)
Default Angle Drill angle from vertical (degrees)
Default Bearing Drill azimuth (degrees)
Default Hole Type Production, Presplit, Buffer, etc.
ID Prefix Prefix for generated Hole IDs
Start Number First number in the auto-generated ID sequence

Modifying a Generated Pattern

After generation, holes behave like any manually placed hole. You can:

Duplicate Detection

When creating or importing patterns with names that already exist:

  1. Kirra checks for duplicate Hole IDs
  2. It detects overlapping hole positions (within tolerance)
  3. A warning is displayed listing the conflicts
  4. You can choose to: Skip duplicates, Rename automatically, or Overwrite

Pattern Statistics

After pattern creation, view statistics via View > Pattern Statistics or by selecting the entity in the TreeView: