*Corresponding: akvishwakarma.min@nitrr.ac.in
Drilling & blasting is the most economical method for rock excavation. Only 20β30% of explosive energy contributes to effective rock breakage.
Remaining 70β80% dissipates as environmental nuisances: air overpressure, flyrock, and blast-induced ground vibrations (BIGV).
BIGV causes backbreak, overbreak, wall failure, slope instability, and damage to surrounding rock mass and nearby structures.
| Structure Type | >25 Hz | 8β25 Hz | <8 Hz |
|---|---|---|---|
| Sensitive / Historical | 10 | 5 | 2 |
| Domestic (brick/cement) | 15 | 10 | 5 |
| Industrial Buildings | 25 | 20 | 10 |
| Industrial (limited life) | 50 | 25 | 15 |
Values in mm/s Β· Source: DGMS, 1997
Develop accurate prediction models for Peak Particle Velocity using five blast design parameters: D, Q, S, B, H
Compare performance of empirical equations, multivariate regression, and four ML algorithms on identical datasets
Quantify the influence of hole depth, burden, and spacing β parameters neglected in most prior studies
Identify the most accurate and generalizable model using RΒ², RMSE, MAE, and cross-validation metrics
| Parameter | Symbol | Unit | Min | Mean | Median | Max | Std Dev | CV (%) |
|---|---|---|---|---|---|---|---|---|
| Distance from blast face | D | m | 50 | 146.74 | 149 | 333 | 70.64 | 48.14 |
| Max. explosive weight/delay | Q | kg | 15 | 43.35 | 49 | 80 | 17.03 | 39.28 |
| Spacing | S | m | 3.0 | 4.62 | 5.0 | 5.0 | 0.61 | 13.14 |
| Burden | B | m | 2.9 | 3.88 | 4.0 | 4.0 | 0.34 | 8.69 |
| Hole Depth | H | m | 2.2 | 4.47 | 4.4 | 7.5 | 1.32 | 29.44 |
| Peak Particle Velocity | PPV | mm/s | 1.32 | 6.63 | 5.22 | 30.7 | 5.25 | 79.18 |
CV = Coefficient of Variation = (StDev/Mean) Γ 100 Β· High CV for PPV (79.18%) indicates significant variability in ground vibration response
| Rank | Model | Type | Test RΒ² | RMSE (mm/s) | MAE (mm/s) | CV RΒ² (Mean Β± SD) | Train-Test Gap | Assessment |
|---|---|---|---|---|---|---|---|---|
| π₯ 1 | XGBoost | ML | 0.862 | 2.281 | 1.667 | 0.461 Β± 0.257 | 0.034 | Highest test accuracy |
| π₯ 2 | SVR | ML | 0.857 | 2.316 | 1.705 | 0.533 Β± 0.390 | β0.026 | Most generalizable |
| π₯ 3 | GBR | ML | 0.760 | 3.004 | 1.973 | 0.276 Β± 0.908 | 0.117 | Moderate stability |
| 4 | RF | ML | 0.637 | 3.694 | 2.307 | 0.328 Β± 0.512 | 0.146 | Lowest ML accuracy |
| 5 | MVR | REG | 0.456 | β | β | β | β | Moderate interpretability |
| 6 | AAH | EMP | 0.243 | β | β | β | β | Best empirical model |
| 7 | USBM | EMP | 0.152 | β | β | β | β | Moderate empirical |
| 8 | BIS 6922 | EMP | 0.091 | β | β | β | β | Poor performance |
| 9 | LAK | EMP | 0.007 | β | β | β | β | Weakest model |
Machine learning models achieve RΒ² = 0.637β0.862, significantly surpassing empirical (0.007β0.243) and regression (0.456) models
RΒ² = 0.862, RMSE = 2.281 mm/s, MAE = 1.667 mm/s β highest predictive accuracy with minimal train-test gap (0.034)
Train-test gap = β0.026 (negative = test slightly outperforms train), indicating excellent generalization to unseen data
SHAP analysis confirms D has the highest impact on PPV, followed by Q, S, B, and H β validating the physical attenuation mechanism
All four empirical models show RΒ² < 0.25, confirming that 2-parameter scaled distance formulations cannot capture site-specific BIGV complexity
XGBoost model enables accurate pre-blast PPV prediction, allowing engineers to verify compliance with DGMS limits (2β50 mm/s) before detonation β preventing structural damage to nearby infrastructure
SHAP-guided parameter sensitivity enables targeted optimization: reducing Q or increasing D are the most effective levers for PPV control; spacing adjustments offer secondary control
Distance is the most influential parameter β monitoring stations should be strategically placed at critical distances from blast faces, particularly near sensitive structures
The model enables optimization of charge per delay (Q) to maximize rock fragmentation while keeping PPV within regulatory limits β balancing productivity and safety
Only 88 datasets from 10 experimental blasts. Limited sample size may affect model generalization and statistical robustness, particularly for cross-validation stability (high SD in CV RΒ²)
Initiation sequence, stemming conditions, powder factor, and local geological discontinuities were maintained relatively consistent and not included as input variables
All data collected from Samaleswari OCP only β a single geological formation (Barakar Formation, Gondwana Supergroup). Model may not generalize to different rock types or geological settings
Rock mass properties (UCS, Young's modulus, P-wave velocity, RQD, joint orientation) were not included as input parameters despite their known influence on seismic wave propagation
Advanced optimization techniques (PSO, GA, Bayesian optimization) were not applied to tune ML model hyperparameters, which could further improve prediction accuracy
Cross-validation RΒ² values (0.276β0.533) are considerably lower than test RΒ² values (0.637β0.862), suggesting that model performance may vary with different data splits
Expand to 300+ datasets across multiple mine sites and geological formations to improve model reliability, generalization, and cross-validation stability
Include UCS, Young's modulus, P-wave velocity, RQD, and joint orientation as additional input variables to capture rock mass influence on BIGV
Develop hybrid models combining XGBoost with metaheuristic optimization (PSO, GA, WOA) for automated hyperparameter tuning and improved accuracy
Explore LSTM, CNN-LSTM, and Transformer architectures for capturing temporal patterns in sequential blast data and wave propagation dynamics
Develop transfer learning approaches to adapt models trained on one mine site to new geological settings with minimal additional data collection
Deploy ML models in an integrated blast monitoring system for real-time PPV prediction and automated safety compliance verification before each blast
Conventional empirical equations (BIS 6922, AAH, LAK, USBM) are insufficient for accurate PPV estimation β they rely solely on scaled distance and ignore collective blast design parameter influence
Multivariate regression provides improved interpretability (RΒ² = 0.456) and confirms direct relationships of Q and S with PPV, and inverse relationships of D, B, and H
Machine learning models significantly outperform empirical and regression approaches by capturing complex non-linear multivariate interactions among blast parameters
XGBoost is recommended as the best model for PPV prediction with RΒ² = 0.862, RMSE = 2.281 mm/s, and MAE = 1.667 mm/s β superior to all other models tested
SHAP analysis confirms Distance > Charge > Spacing > Burden > Hole Depth in terms of influence on PPV β providing physically interpretable feature importance
XGBoost with 5-fold cross-validation is recommended for blast-induced ground vibration prediction in opencast mining operations. Future work should incorporate geotechnical parameters and larger multi-site datasets for improved generalization.