某水电站垫层蜗壳平面铺设范围的影响研究

Impact Study of the Membrane Laid Scope of Spiral Cases in a Hydropower Station

结合某大型水电站机组安装工程,采用三维有限元方法,从蜗壳外围混凝土应力与配筋、混凝土承载比、座环和机墩位移等3个方面讨论了垫层平面铺设范围的影响。研究结果表明,随着垫层平面铺设范围的增加,垫层区域的蜗壳外围混凝土拉应力和损伤区域明显减小,配筋量降低,座环、定子和下机架基础的不均匀上抬位移也明显减小。在综合考虑上述3个方面的影响后,建议dc-270方案作为该水电站钢蜗壳的垫层铺设方案。

By three-dimensional finite element method,the effect of membrane laying range to the stress and reinforcement of surrounding concrete,bearing ratio,stay ring and generator pedestal displacement have been discussed.The research results show that with the increase of membrane laid range,the tensile stress and damage area of concrete surrounding the spiral case in the membrane area are significantly reduced,and the reinforcement is accordingly decreased.Moreover,the uneven rising displacement of the stay ring,stator and lower bracket foundation is obviously decreased.In this paper,after considering the influence of the above three aspects,the dc-270 scheme is suggested as the membrane laying scheme of steel spiral case of the hydropower station.