软岩巷道开挖支护的颗粒离散元模拟

廖九波^{1, 2}，李夕兵^{1, 2}，周子龙^{1, 2}，邹洋^{1, 2}

(1. 中南大学 资源与安全工程学院，湖南 长沙，410083；2. 中南大学 深部金属矿产开发与灾害控制湖南省重点实验室，湖南 长沙，410083)

摘 要：针对马路坪矿的一种典型软岩巷道，根据其地质条件和力学特性，将巷道围岩分成弹性区、塑性区和破裂区，进行弹塑性力学分析，得到其位移的封闭解析解。采用颗粒流软件PFC2D对软岩巷道开挖后围岩变形破坏规律进行数值模拟，探讨围岩各个关键部位的位移分布特征，研究结果与巷道弹塑性解能很好地吻合，说明基本模型的正确性，进而利用模型模拟支护，分析支护效果随支护时间的变化规律。所得结果可为类似巷道的破裂机制分析和支护设计提供理论指导。

关键词：软岩巷道；弹塑性模型；颗粒流模拟；位移；支护

Numerical simulation of liner during soft tunnel excavation by particle flow code based on discrete element method

       LIAO Jiubo^{1, 2}, LI Xibing^{1, 2}, ZHOU Zilong^{1, 2}, ZOU Yang^{1, 2}

(1. School of Resources and Safety Engineering, Central South University, Changsha 410083, China;2. Hunan Key Laboratory of Resources Exploitation and Hazard Control for Deep Metal Mines,Central South University, Changsha 410083, China)

Abstract:Based on the specific geological condition and mechanical properties of rock, the surrounding rocks of a typical soft tunnel of Maluping mine, were divided into three regions, i. e. the elastic region, the plastic region and the cracked region. The closed-form analytical solutions for the displacement in the three regions were derived by an elastoplastic model. Finally, By means of particle flow software PFC2D deformation failure regularity for soft tunnel after excavation was simulated. The displacement distribution of different parts in surrounding rock in detail was analyzed. The results match those of the elastoplastic analysis well, which proves the correctness of the basic model , And then by means of the model the tunnel after lining was simulated, and the variation law of the lining effect versus the lining time was researched. The relevant results may provide theoretical foundations for the cracked mechanism analysis and reinforcement of the similar tunnels.

Key words:soft tunnel; elastoplastic model; particle flow simulation; displacement; liner