水电站充水保压蜗壳接触行为及座环受力研究

为研究充水保压蜗壳进口结构连接形式对钢蜗壳-混凝土接触面传力和座环受力的影响，结合国内某巨型水电站，基于ABAQUS平台进行了三维有限元仿真分析。结果表明：保压间隙最早闭合的区域出现在蜗壳进口断面外侧、45°断面外侧以及270°断面内侧，达到保压水头后，未闭合的区域与最早闭合的区域在空间上正好相对；进口结构连接形式对保压间隙的闭合时机存在显著影响，伸缩节过缝时设置止推环以及蜗壳-钢管直接连接都能有效延迟保压间隙的提前闭合时机，三维仿真分析时不能忽略进口结构连接形式这一关键因素。与垫层蜗壳相比，充水保压蜗壳座环的受力状态同样值得重视，伸缩节过缝时设置止推环以及蜗壳-钢管直接连接都能显著改善保压蜗壳座环水平面内的受力状态。

Study on Contact Behavior and Forced State of Stay Ring for Preloading Filling Spiral Case in Hydropower Station

In order to analyze the influences of connecting type of inlet structure on contact behavior and forced state of stay ring in preloading filling spiral case, three-dimensional FEM simulation is performed by ABAQUS in combination with one huge hydropower station. It is indicated that the earliest closed region locates at the outside of inlet section and 45 degrees section and the inside of 270 degrees section where are opposite to the unclosed region when preloading head is applied. Connecting type of inlet structure has markedly effect on closed time of preloading gap which can be delayed effectively by adding anti-thrust when explanation joint is installed or welding spiral case inlet directly with steel pipe. This key point should not be ignored in three-dimensional FEM simulation. Compared to spiral case with a membrane, the forced state of stay ring should also be in focus for preloading filling spiral case. The forced state can be improved effectively by adding anti-thrust when explanation joint is installed or welding spiral case inlet directly with steel pipe.