中文摘要：

本文结合国内两个典型的巨型水电站,基于单元结点力的方法对坝后式水电站伸缩节过缝和垫层管过缝条件下蜗壳座环的受力特性展开了研究,探讨了对座环受力较优的垫层平面铺设范围。研究结果表明,两类过缝措施条件下,座环承受最小不平衡力的垫层平面铺设范围为45°之前或270°断面之后;而对座环承受不平衡扭矩而言,则无明显的最优垫层平面铺设范围。垫层蜗壳采用伸缩节过缝时,止推环对座环承受水流向不平衡力及不平衡扭矩的改善效果明显且稳定;而垫层管过缝时,止推环的作用效果不明显,此时引水钢管已经起到了止推环的作用。在单机容量基本一致且采用垫层蜗壳埋设方式的条件下,高水头电站座环承受的水平面内不平衡力和不平衡扭矩更大,座环的受力更应该引起重视。

英文摘要：

Mechanical characteristics of stay ring are studied using nodal force method for two huge hydropower stations when expansion joint and cushioned pipe are separately used for joint passing, and the optimized plane covering range of cushion layer is discussed. In view of unbalanced water thrust borne by stay ring, the plane covering of cushion layer should be located in a range before 45° or after 270°. In view of unbalanced torque, no optimal plane covering range exists. For the expansion joint scheme, the effect of anti-thrust ring in reducing the unbalanced water thrust and torque borne by stay ring is obvious and stable. For the cushioned pipe scheme, the effect of anti-thrust ring can be ignored because the steel pipe plays a role of anti-thrust ring. Under the condition of the same unit capacity, the stay ring of a turbine with high water head bears large unbalanced water thrust and torque, and more attention should be paid to its load conditions.