子模型法在拱坝泄水底孔应力分析中的应用

Application of Sub-model Method in Stress Analysis of Arch Dam's Bottom Outlet

应用有限元子模型法对某工程高水头薄拱坝泄水底孔进行了三维有限元计算,分析了底孔有压段的孔口应力及上、下游悬臂结构的应力状态。结果表明上游悬臂和坝体交接处底孔侧壁部位顺水流向拉应力较大,而传统的平面有限元法计算拱坝泄水孔口的应力时,认为顺水流向的应力比较小;又通过多方案的计算,对不同模型计算结果的差异进行了分析。相对于传统计算方法,用子模型法对高水头薄拱坝泄水孔口进行有限元分析,可以大大降低计算工作量,减少计算所花费的时间,并有利于提高计算的精度。

Here ,the finite element sub-model method is applied to the 3D calculation of a high-head and thin arch dam engineering ,and the opening stress of the pressure section of its bottom outlet and the stress state of its upstream and downstream cantilevers are analyzed .The results show that the tensile stress of the flow direction of the bottom outlet sidewall in the intersection of upstream cantilevers and dam body is large ,but with the traditional plane finite element method ,it is considered that this tensile stress is small when calculating the stress near orifices .Then by calculating multiple solutions ,the different calculation results of different models are analyzed .Compared with the traditional calcu-lation method ,using the sub-model method for the analysis of the high-head and thin arch dam’s bottom outlet with finite element analysis could greatly reduce the computational effort and time ,and help to improve the accuracy of the calcula-tion .