爆破扰动荷载对深部竖井岩体稳定性分析

Analysis of the Stability of Rock Masses in Deep Vertical Shafts under Blasting Disturbance Loads

  • 摘要: 深部竖井在采用钻爆法施工过程中,爆破荷载对岩壁作用造成的服役效能损伤尤为突出。通过数值模拟分析爆破冲击荷载对竖井工程围岩的稳定性的影响过程,基于最大名义应变准则和摩尔库仑破坏准则构建复合损伤模型,进而定量表征竖井围岩爆破损伤范围。研究结果表明,爆破荷载作用下井筒围岩的损伤演化具有显著的时空动态特征,并伴随着力学耦合机制。损伤发展在时间维度上呈现阶段性集中现象,爆破荷载在后期围岩动态响应以塑性耗散能为主导,岩石在此阶段发生损伤和破坏,有可能存在岩爆风险。相关研究结果可为深部竖井安全施工提供支撑。

     

    Abstract: During the construction of deep vertical shafts using the drill−and−blast method, the blasting−induced load acting on the shaft wall has caused significant degradation in the service performance of the surrounding rock. To investigate this issue, the influence process of blasting impact loads on the stability of the surrounding rock in shaft engineering was analyzed through numerical simulation. A coupled damage model was established based on the maximum nominal strain criterion and the Mohr–Coulomb failure criterion, with the aim of investigate the effects of blasting on the surrounding rock mass. In the research process, numerical simulation techniques were employed to reproduce the dynamic response of the surrounding rock under blasting loads. The loading conditions associated with blasting were systematically applied, and the mechanical response and damage evolution of the surrounding rock were examined. The composite damage model integrating the maximum nominal strain criterion and the Mohr–Coulomb failure criterion was used to describe the progressive degradation behavior of the rock mass. Based on this model, the spatial distribution and temporal evolution of damage within the surrounding rock were quantitatively evaluated. The results show that the damage evolution of the shaft surrounding rock under blasting loads exhibits pronounced spatiotemporal dynamic characteristics, accompanied by a distinct mechanical coupling mechanism. In the temporal dimension, damage development presents a staged concentration phenomenon. During the later stage of blasting−induced dynamic response, plastic dissipation energy dominates the energy evolution process of the surrounding rock. At this stage, the rock mass undergoes significant damage and failure, and there exists a potential risk of rock burst. The findings of this study can provide a basis for the safe construction of deep vertical shafts.

     

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