水电站深部洞室群应力场相关性研究

Study on Relationships between Stress Regimes of Deep Tunnels in a Hydraulic Power Plant

结合新疆某水电站的深部洞室群稳定性研究工作,利用三维弹塑性有限元方法,详细研究了水电站3个洞室的应力场在开挖过程中的变化规律,发现了"洞室群应力恶化效应",即后期的洞室施工对邻近洞室的应力场有恶化作用,加剧了前期开挖洞室的应力集中效应;以及"洞室群圆弧拱顶应力优化效应",即后期的洞室施工对邻近洞室拱顶的应力场有优化作用,减缓了前期开挖洞室拱顶的应力集中效应,这一规律的发现将对深部洞室群稳定性控制具有一定的意义.

Based the research on the stability problem of deep tunnels of a hydraulic power plant in Xinjiang, the relationships of stress regimes of tunnels during the excavation were analyzed in detailed by setting typical stress monitoring points in different tunnels with the 3-D elastic and plastic finite element method. And the stress states of these monitoring points revealed the variation laws of stress regimes of three tunnels during the excavation. The results show that the later construction of tunnel deteriorates the stress field of adjacent tunnel, i.e. intensify the stress concentration effect in the tunnel excavated formerly; such a phenomenon is called “stress deteriorating effect in group tunnels”. Meanwhile, the results indicate that the later construction of tunnel optimizes the stress field of arch top of adjacent tunnel, i.e. alleviate the stress concentration effect in arch top of the tunnel excavated. 5figs., 2tabs., 10refs.