ISSN 1000-3665 CN 11-2202/P

    基于RHT本构的隧道爆破参数优化与振动损伤数值研究

    Numerical study of tunnel blasting parameter optimization and vibration damage based on the RHT constitutive model

    • 摘要: 为了解决爆破参数优化问题以及考虑炮孔间相互作用对围岩损伤空间分布的影响,先利用数值试算与冲击试验相对照的方法,标定出大理岩Riedel-Hiermaier-Thoma本构模型参数。接着,对隧道全断面爆破开挖开展模拟计算,考察了多炮孔间相互作用下围岩爆破损伤演化过程。最后,基于起爆顺序、径向不耦合系数和分段间隔装药3种方法来优化爆破参数,并对质点振动和围岩损伤进行了深入分析。结果表明:标定所得的本构参数可准确描述大理岩动态应力-应变响应,且模拟结果能很好地揭示爆破损伤演化规律;岩石损伤从爆心处向外发展,随后在炮孔连线上连接贯通;相比于上述其他2种方法,当径向不耦合系数k小于1.33时,在保证爆破效果前提下改变k值能有效地降低围岩的爆破损伤;隧道竖向平均振动速度要大于水平向的对应值,且竖向拱顶和底板中部对爆破振动呈现较高的敏感性。研究结果为工程实践中爆破参数优化选取和围岩损伤精确评估等可提供参考。

       

      Abstract: To solve the optimization problem of blasting parameters and consider the influence of interaction between blastholes on the spatial distribution of surrounding rock damage, the Riedel-Hiermaier-Thoma constitutive model parameters of marble were first calibrated from numerical trial calculation and impact test. Then, the blasting excavation of a tunnel in full section was numerically simulated, and the evolution process of blasting damage of surrounding rocks under the interaction of multiple boreholes was investigated. Finally, the blasting parameters were optimized based on the three methods of initiation sequence, radial uncoupling coefficient and segmented interval charge, and the particle vibration and surrounding rock damage were further analyzed. The results show that the obtained constitutive parameters accurately describe the dynamic stress-strain response of the marble, and the simulated results can well reveal the evolution law of blasting damage. The rock damage develops outward from the blasthole center, and then the damage is connected and coalesced along the borehole connection line. Compared with the aforementioned other two methods, when the radial uncoupling coefficient k is less than 1.33, the blast damage of surrounding rock can be effectively reduced by changing the k value on the premise of ensuring the blasting effect. The average vibration velocity in the vertical direction of tunnel is greater than that in the horizontal direction, and the apex of arch and the middle of floor in this direction are more sensitive to blasting vibration. The research results in this study can provide reference for optimum selection of blasting parameters and accurate evaluation of surrounding rock damage in practical engineering.

       

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