垫层对水电站机墩及座环刚度的影响

机墩组合结构和座环结构为水轮发电机组主要的支撑体系，其刚度对机组的稳定性尤为重要。为掌握垫层蜗壳结构中软垫层对机墩及座环刚度的影响，以某巨型水电站工程为例，建立了其地下厂房结构三维有限元模型，分析了不同的垫层模拟方式即单元形式、铺设范围和压缩模量对机墩及座环刚度的影响。计算结果表明，各垫层模拟方式的变化对机墩水平刚度基本无影响；垫层铺设范围的变化对机墩竖向刚度和座环径向刚度基本无影响；垫层压缩模量的变化对机墩竖向刚度和座环径向刚度有一定影响，但影响较小，变幅最大不超过7.5％。

Effect of Cushion Layer on Stiffness of Generator Pedestal and Stay Ring Structure in Hydropower Station

The generator pedestal and stay ring structure is main supporting system of the hydro generator set, whose stiffness plays important effect on the stability of generating unit. This paper presents the effect of cushion layer on stiffness of the generator pedestal and stay ring structure. For this purpose, taking a large hydropower station project for an example, the study that a simulation mode of cushion layer, base on different element form, covering range and compressed modulus of cushion layer under stiffness of the generator pedestal and stay ring structure represented by a three-dimensional finite element model of underground power house, is conducted. The results indicate that the simulation modes of cushion layer have not impact basically on the horizontal stiffness of generator pedestal, and the covering ranges of cushion layer also have not impact basically on the vertical stiffness of generator pedestal and the radial stiffness of stay ring; but the compressed modulus of cushion layer have little influence on the vertical stiffness of generator pedestal and the radial stiffness of stay ring with a maximum change range of less than 7.5%.