Figure 1
Three elements characterizing a contour quality [1].
Figure 2
Spacing of measurement sections within a single blasting round [1].
Figure 3
A cross-section and a drill pattern for the studied niche.
Table 1
Parameters of the FARO Focus 3D S150 scanner and scanning process [23].
| Parameter | Value |
|---|---|
| Range | 0,6 m do 150 m |
| Precision | +/−1 mm |
| Measurement speed | Up to 976,000 points/s |
| Laser | Class 1 |
| Weight | 4.2 kg |
| Size | 230 × 183 × 103 mm |
| Control | Touch display and WLAN |
| Extra | Global Positioning System (GPS), compass, altimeter, two-axis compensator |
| Measurement range | Indoor up to 10 m |
| Resolution [MPts] | 28.0 (1/5) |
| Quality | 4× |
| Horizontally | 0°do 360° |
| Perpendicularly | −60°do 90° |
| Scanning time [mm:ss] | 05:28 |
| Scan size [Pts] | 8192 ×3413 |
Figure 4
(a) Scanner FARO Focus 3D S150. (b) Location of the measuring station.
Figure 5
Division of the acquired point cloud.
Figure 6
Side 1 (a) and roof (b) models for the 2nd blasting round created in AutoCAD Civil 3D.
Figure 7
Measurement points arrangement on the planned contour profile.
Figure 8
Modeled and planned contour lines.
Figure 9
Tunnel cross-section view of the measured point cloud.
Figure 10
Modeled tunnel contour surface determined for a single blasting round.
Figure 11
Cross-sections 1 and 2 for each of the three blasting rounds, obtained on the basis of the TIN surface.
Table 2
Summary of the results obtained by the laser profiling technique (according to [1]).
| Round | Element | Cross-section | Parameter | TCIR | |
|---|---|---|---|---|---|
| Overbreak depth (Od) [cm] | Contour roughness (RCL) [−] | ||||
| Round 1 | Side 1 | 1 | 11.661 | 1.001 | 71.657 |
| 2 | 12.379 | 1.001 | |||
| Side 2 | 1 | 11.102 | 1.003 | ||
| 2 | 6.389 | 1.001 | |||
| Roof | 1 | 14.232 | 1.060 | ||
| 2 | 13.906 | 1.055 | |||
| Entire round | 1 | 13.092 | 1.039 | ||
| 2 | 12.097 | 1.035 | |||
| Round 2 | Side 1 | 1 | 9.612 | 1.004 | 71.343 |
| 2 | 9.825 | 1.002 | |||
| Side 2 | 1 | 12.813 | 1.004 | ||
| 2 | 12.162 | 1.004 | |||
| Roof | 1 | 10.930 | 1.045 | ||
| 2 | 17.387 | 1.073 | |||
| Entire round | 1 | 11.046 | 1.030 | ||
| 2 | 14.764 | 1.048 | |||
| Round 3 | Side 1 | 1 | 11.241 | 1.006 | 72.190 |
| 2 | 7.84 | 1.001 | |||
| Side 2 | 1 | 7.430 | 1.002 | ||
| 2 | 9.593 | 1.002 | |||
| Roof | 1 | 14.458 | 1.058 | ||
| 2 | 12.796 | 1.052 | |||
| Entire round | 1 | 12.409 | 1.039 | ||
| 2 | 11.164 | 1.034 | |||
Table 3
Summary of the results obtained by the TLS technique.
| Round | Element | Parameter | TCIsR | |
|---|---|---|---|---|
| Overbreak depth [cm] | Contour roughness [−] | |||
| Round 1 | Side 1 | 8.624 | 1.116 | 64.232 |
| Side 2 | 10.893 | 1.155 | ||
| Roof | 14.111 | 1.192 | ||
| Entire round | 12.640 | 1.171 | ||
| Round 2 | Side 1 | 9.146 | 1.042 | 67.943 |
| Side 2 | 11.149 | 1.069 | ||
| Roof | 12.416 | 1.140 | ||
| Entire round | 11.737 | 1.109 | ||
| Round 3 | Side 1 | 12.094 | 1.055 | 68.578 |
| Side 2 | 6.695 | 1.072 | ||
| Roof | 12.335 | 1.123 | ||
| Entire round | 11.350 | 1.102 | ||
Figure 12
Values of the overbreak depth for individual elements of each of the three blasting rounds.
Figure 13
Values of the contour roughness for individual elements of each of the three blasting rounds.
Figure 14
Values of the overbreak depth for individual elements of each of the three blasting rounds.
Figure 15
Values of the contour roughness for individual elements of each of the three blasting rounds.
Figure 16
Planned and modeled (TIN) contour surfaces and volume Va.