围岩隧道蠕变塌方的离散元模拟研究

Discrete Element Simulation of Tunnel Creep Collapse in Surrounding Rock

摘要: 本文以某公路隧道为工程背景，采用离散元数值模拟方法，系统探讨了开挖扰动和蠕变效应对裂隙围岩稳定性的影响，揭示了塌方灾害的时空演化规律。通过PFC3D软件建立了隧道蠕变模型，模拟了隧道围岩在开挖扰动和长期蠕变作用下的应力分布和变形特征。研究结果表明，隧道开挖后围岩应力分布发生显著变化，尤其是在隧道周围的围岩区域，应力集中现象明显。通过应力腐蚀模型，模拟了材料在长期应力和腐蚀环境耦合作用下的力学响应，有效捕捉了岩石在长期载荷作用下的变形与破坏特征。本研究为隧道工程支护设计和长期安全运营提供了科学依据，对实际工程具有重要的参考价值。

Abstract: Based on the engineering background of a highway tunnel, the influence of excavation disturbance and creep effect on the stability of fractured surrounding rock is systematically discussed by using discrete element numerical simulation method, and the spatio-temporal evolution law of collapse disaster is revealed. The creep model of tunnel is established by PFC3D software, and the stress distribution and deformation characteristics of tunnel surrounding rock under excavation disturbance and long-term creep are simulated. The results show that the stress distribution of surrounding rock changes significantly after tunnel excavation, especially in the surrounding rock, the stress concentration is obvious. The stress corrosion model is used to simulate the mechanical response of the material under the coupling action of long-term stress and corrosion environment, and effectively capture the deformation and failure characteristics of the rock under long-term load. This study provides scientific basis for tunnel engineering support design and long-term safe operation, and has important reference value for practical engineering.