Optimizing Blasting Schemes: A Comprehensive Approach through Macro–Micro Simulation and Field Experiment

• Published in: Geotechnical and geological engineering 2024-07, Vol.42 (5), p.3877-3896
• Main Authors: Chen, Yun-Juan, Su, Jia-Rui, Wang, Hao-Shuang, Xi, Hou-Lei, Gao, Dong
• Format: Article
• Language: English
• Subjects: Blasting; Civil Engineering; Crack propagation; Crushed stone; Density; Diffusion rate; Dredging; Earth and Environmental Science; Earth Sciences; Excavation; Field study; Field tests; Geotechnical Engineering & Applied Earth Sciences; Hydrogeology; Optimization; Original Paper; Propagation; Rock masses; Rocks; Simulation; Software; Speed control; Stress concentration; Stress waves; Terrestrial Pollution; Tunnels; Velocity; Vibration; Waste Management/Waste Technology
• ISSN: 0960-3182; 1573-1529
• DOI: 10.1007/s10706-024-02763-y

The contour shaping effect of hard granite tunnels is relatively unsatisfactory, and the research on the influence of various blasting parameters on this effect lacks sufficient depth. This paper aims to analyze the blasting law of density coefficient based on stress–strain and damage changes, dynamically examine the blasting process from macro–micro perspectives, and achieve a comprehensive assessment of blasting safety by focusing on vibration speed control. Finally, drawing upon an actual project, an optimized scheme for tunnel blasting involving density coefficient adjustment and plugging length optimization is proposed. The reliability of simulations is verified through field tests while ensuring effective guidance for the actual project. The results indicate that a density coefficient of 1.0 yields the highest peak in effective stress, resulting in superior connectivity within the peripheral hole crushing area under stress wave superposition. Consequently, tunnel excavation achieves better molding effects, effectively controlling the occurrence of over-under cutting at the tunnel shoulder and promoting more uniform diameter distribution of crushed stones after blasting. Moreover, employing a blocking length of 30 cm facilitates enhanced development of internal rock fissures while effectively controlling particle dispersion mode and distance. This approach improves large-scale undercutting within the middle and bottom sections of the hand face rock mass, enhances explosive utilization rate, reduces diffusion of harmful gases, minimizes peak vibration velocity around the excavation surface, and mitigates disturbance caused by blasting on initial support.