Fig. 1.
TBM and disk cutter structure. TBM, tunnel boring machine
Fig. 2.
Motion decomposition of disk cutter
Fig. 3.
Rock breaking mechanism of disk cutter
Fig. 4.
Force diagram of disk cutter
Fig. 5.
Disk cutter with normal wear dismantled on site
Fig. 6.
Geological profile of the tunnel
Fig. 7.
Introduction of cutter head and cutter
Table 1.
A 19-inch disk cutter with basic parameters
| Material name of cutter ring | Outer diameter of cutter ring (mm) | HRC | Width of the cutter edge (mm) | Cutter spacing (mm) |
|---|---|---|---|---|
| 4Cr5MoSiV1 | 483 | 50–54 | 19 | 80 |
Fig. 8.
Disk cutter wear values were measured on site
Fig. 9.
Actual wear data and installation radius of disk cutter
Fig. 10.
Normally worn disk cutter ring and test piece
Fig. 11.
Hardness test of disk cutter ring
Fig. 12.
Impact test of disk cutter ring
Fig. 13.
SEM and OES test of disk cutter ring material. (A) SEM test process. (B) OES test process. OES, optical emission spectroscopy; SEM, scanning electron microscope
Fig. 14.
Metallurgical structure of disk cutter ring material
Table 2.
Chemical composition of disk cutter ring material
| Chemical element | C | Cr | Mn | Si | Mo | V | S | P |
|---|---|---|---|---|---|---|---|---|
| Chemical composition of cutter ring (%) | 0.49 | 5.15 | 0.47 | 1.07 | 1.46 | 0.98 | 0.009 | 0.012 |
| Chemical composition of 4Cr5MoSiV1 (%) | 0.32– 0.45 | 4.75– 5.50 | 0.20– 0.50 | 0.80– 1.20 | 1.10– 1.75 | 0.80– 1.20 | ≤ 0.03 | ≤ 0.03 |
Fig. 15.
Rock samples
Fig. 16.
Geological conditions along the line. (A) Stratum classification. (B) Rock mass strength distribution
Fig. 17.
Contact force diagram
Table 3.
Structure parameters of disk cutter ring
| Outer diameter of cutter ring (mm) | Width of cutter ring (mm) | Blade width (mm) | Cutting edge angle | Fillet radius (mm) |
|---|---|---|---|---|
| 483 | 89 | 19 | 24° | 32 |
Fig. 18.
Model for rock breaking with disk cutter
Table 4.
Rock attributes of each working condition
| Condition | Compressive strength (MPa) | Tensile strength (MPa) | Density (g/mm3) |
|---|---|---|---|
| Condition 1 | 120 | 11.2 | 2.9 × 10−3 |
| Condition 2 | 90 | 8.7 | 2.7 × 10−3 |
| Condition 3 | 70 | 6.9 | 2.6 × 10−3 |
| Condition 4 | 50 | 4.4 | 2.5 × 10−3 |
Fig. 19.
Simulation results derived post-processing
Table 5.
Comparison of vertical forces from simulation and theoretical models
| Condition | Average vertical force of simulation model (kN) | Vertical forces calculated by CSM model (kN) | Absolute value relative error |
|---|---|---|---|
| Condition 1 | 201.3 | 205.9 | 2.2% |
| Condition 2 | 149.4 | 156.3 | 4.3% |
| Condition 3 | 116.2 | 122.3 | 4.9% |
| Condition 4 | 77.8 | 84.1 | 7.5% |
Fig. 20.
Comparison between the predicted wear values and the actual wear data
Fig. 21.
Comparison between actual wear data and predicted wear values under different penetration