Preparation of Dust Suppressant for Water Bags in Tunnel Blasting and its Application in Similarity Simulation

To address dust pollution challenges in tunnel drilling and blasting operations, this study developed an eco-friendly high-efficiency water bag dust suppressant. The innovation significantly enhances the wetting and agglomeration capabilities of water bags, thereby optimizing dust control performance in hydrostatic blasting applications. Guided by safety and environmental protection principles, three surfactants (OB-2, APG1214, and 1631) and their critical micelle concentrations (CMC) were determined through surface tension measurements. Subsequently, three composite dust suppressants (S-1, S-2, and S-3) were formulated using binary combination methodology. Their dust-suppression efficacy was systematically assessed using surface-tension analysis and contact-angle measurements. A 1:10-scale tunnel-blasting model was developed based on geometric similarity principles derived from plateau tunnel conditions. Furthermore, controlled experiments compared three configurations: no water bag placement, placement of ordinary water bags, and placement of dust suppressant water bags. A real-time dust concentration monitoring system quantified particulate concentration variations across the three experimental configurations. Results demonstrated superior performance by the dust suppressant S-1 (OB-2/APG1214 composite), exhibiting an optimal surface tension of 29.19 mN/m and wettability (27.7° contact angle). In scaled simulations, scenario Ⅲ (suppressant-treated water bags) achieved a sectional dust concentration of 12.22 mg/m³ at t=21 s, representing reductions of 79.89% and 60.32% relative to scenarios Ⅰ (no treatment) and Ⅱ (conventional water bags), validating exceptional particulate control efficacy.