【摘要】 大型地下洞室的开挖施工往往面临复杂的地质环境以及复杂的施工程序,研究这种条件下围岩的应力和变形规律不仅有助于进一步认识岩体的力学性质,而且可以为大型地下工程的支护设计和施工提供重要的参考,因而具有一定的实际意义。地下洞室的变形及稳定性问题主要集中于顶拱围岩,以向家坝水电站地下厂房为例,采用三维离散元程序3DEC,研究了在复杂的开挖条件下洞顶围岩的位移和应力变化规律,将计算位移与实际监测结果进行了对比,提出适当的支护时机是系统支护滞后于掌子面约5~8 m。更多还原

【Abstract】 Complex geological condition and construction procedure are often met while constructing the big underground cavern,so study of stress and deformation of the surrounding rock can not only help us further understand the mechanical properties of rock mass,but also provide reference for support design and construction of big underground cavern.Deformation and stability of the underground cavern mainly focus on the crown of the chamber.Taking the underground power house of the Xiangjiaba hydropower station as an example,and introducing the three-dimension discrete element method(3DEC),the authors has studied the variations of displacement and stress under the complex excavation condition,compared the calculated data with the monitoring results,and proposed that the proper support distance is 5m delay the constructing face.更多还原