【摘要】 用非线性有限元法对金家坝水电枢纽施工导流洞的开挖进行数值模拟,得出了施工及运行期各阶段的大小主应力曲线图、塑性区分布图、钢支撑的轴力和弯矩图,以及隧洞洞壁的位移趋势。分析结果表明,钢支撑端点存在应力集中现象,但应力集中的范围极小。加锚杆支护后,应力集中向围岩深处扩散,应力值大小降低,塑性区几乎消失,拱顶开挖完成后,顶部下沉位移逐渐趋于稳定。从而验证了设计方案的可行性,并为施工提供了可靠的依据。更多还原

【Abstract】 In this paper,the nonlinear FEM is used for numerical simulation of excavation of diversion tunnel for Jin Jiaba hydroelectric junction.The curve charts of maximum principal stresses,the minimum principal stresses and the scatterplot of plastic area,the chart of axial force and moment of the steel support,and the displacement tendency of the tunnel wall are obtained.It can be concluded from the results that the extent of the stress concentration around the end of the steel support is quite limited.After anchoring shaft,the stress concentration is extended to the deth of the wall rock,the value is decreased,and the plastic area is almost disappeared.After the vault is excavated,the displacement of the top becomes stable.Therefore,the feasibility of the design plan is proved to be sure,and the guidance for construction is provided.更多还原