A Risk-Driven Probabilistic Framework for Blast Vibrations in Twin Tunnels: Integrating Monte Carlo Simulation to Quantify Cavity Effects


Karadoğan A., Özyurt M. C., Kalaycı Şahinoğlu Ü., Özer Ü., Akgündoğdu A.

APPLIED SCIENCES, vol.15, no.23, pp.1-23, 2025 (SCI-Expanded, Scopus)

  • Publication Type: Article / Article
  • Volume: 15 Issue: 23
  • Publication Date: 2025
  • Doi Number: 10.3390/app152312643
  • Journal Name: APPLIED SCIENCES
  • Journal Indexes: Scopus, Science Citation Index Expanded (SCI-EXPANDED), Compendex, INSPEC, Directory of Open Access Journals
  • Page Numbers: pp.1-23
  • Istanbul University-Cerrahpasa Affiliated: Yes

Abstract

Predicting blast-induced vibrations in twin tunnels is challenging due to complex wave-cavity interactions, which render conventional scaled-distance (PPV-SD) models inadequate. This study introduces a hybrid empirical-probabilistic framework to quantify the probability of exceeding regulatory vibration thresholds. Field data from the Northern Marmara Highway project first quantitatively confirm the severe degradation of the classical scaled-distance (PPV-SD) method in twin-tunnel geometry, reducing a strong correlation (R = 0.82) to insignificance. A Random Forest sensitivity analysis, applied to 123 blast records, ranked the governing parameters, guiding the development of a deterministic multi-parameter regression model (R = 0.72). The core innovation of this framework is the embedding of this deterministic model within a Monte Carlo Simulation (MCS) to propagate documented input uncertainties, thereby generating a full probability distribution for PPV. This represents a fundamental advance beyond deterministic point-estimates, as it enables the direct calculation of exceedance probabilities for risk-informed decision-making. For instance, for a regulatory threshold of 10 mm/s, the framework quantified the exceedance probability as P (PPV > 10 mm/s) = 5.2%. The framework’s robustness was demonstrated via validation against 100 independent blast records, which showed strong calibration with 94% of observed PPV values captured within the model’s 90% confidence interval. This computationally efficient framework (<10,000 iterations) provides engineers with a practical tool for moving from deterministic safety factors to quantifiable, risk-informed decision-making.