离散裂隙网络模拟在地下硐室稳定性中的应用——以甘肃北山地下实验室为例

Application of Discrete Fracture Network Simulation in the Stability of Underground Chamber: Taking Beishan UndergroundLaboratory in Gansu Province as an Example

以甘肃北山地下实验室为研究对象,开展了离散裂隙网络-离散元(discrete fracture network-discrete element method, DFN-DEM)耦合方法在花岗岩地下硐室围岩稳定性分析方面的探索研究。选取地下实验室工程勘察范围内代表性勘察钻孔和地表露头裂隙数据进行统计分析,利用三维离散单元软件3DEC构建离散裂隙网络(discrete fracture network, DFN)和等效岩体模型,模拟分析了地下实验室-560 m水平试验巷道的硐室的稳定性。结果表明:硐室开挖引起硐室围岩应力重分布,裂隙与硐室开挖面相交部位发生应力集中现象,硐室围岩出现位移变形;在现有条件下,硐室围岩变形量较小,应力集中程度不高,地下硐室稳定性较好。

Taking the Beishan underground laboratory in Gansu Province as the research object,an exploratory study on the stability analysis of the surrounding rock of granite underground chambers was carried out using the discrete fracture network-discrete element(DFN-DEM)coupling method.The representative survey borehole and surface outcrop fracture data within the engineering survey scope of the underground laboratory were selected for statistical analysis.The discrete fracture network(DFN)and equivalent rock mass model were constructed by using the three-dimensional discrete element software 3DEC.The stability of the chamber of the underground laboratory-560 m horizontal test roadway was simulated and analyzed.The results show that the excavation of the chamber causes the redistribution of stress in the surrounding rock of the chamber.Stress concentration occurs at the intersection of the crack and the excavation surface of the chamber.The surrounding rock of the chamber has displacement and deformation.Under the existing conditions,the deformation of the surrounding rock of the chamber is small,the stress concentration is low,and the underground chamber has good stability.