大型机组直埋式蜗壳结构不同限裂措施的三维非线性分析

 三峡工程右岸电站15＃机组蜗壳采用直接埋入混凝土的方式，采取合理的配筋和有效的结构措施以保证结构安全是研究的重点。通过对采用不同配筋方案及结构措施后的蜗壳及其外围混凝土结构进行三维非线性有限元分析，研究混凝土裂缝分布、钢衬钢筋应力、结构位移等，比较采取不同结构措施所产生的效果。计算结果表明，仅靠增加配筋量不能防止住结构产生贯穿性裂缝和有效降低结构的不均匀上抬位移,延长垫层敷设范围和局部提高混凝土标号对减少混凝土开裂区域、减小裂缝开度、降低定子和下机架基础板的不均匀上抬位移等有明显作用，且局部提高混凝土标号比增加一层钢筋的效果好。

Three-dimensional Nonlinear Analysis on Directly Embedded Spiral Case of Large-scale Turbine Unit with Various Measures of Restricting Cracks

Since the spiral case of No.15 turbine unit of TGP Hydroelectric Power Station was embedded in concrete directly,the emphasis of research were to obtain a rational reinforcement project and structural measures to guarantee the security of structure.The structures with different reinforcement projects and structural measures were analyzed by three-dimensional nonlinear finite-element method.The distribution and width of concrete cracks,the stress of steel plate and reinforcement,the displacement of structure...