坝后背管结构有限元分析探讨

以李家峡坝后背管为依托，借助具有强大结构分析功能的有限元软件ANSYS分析坝后背管结构应力状态。经分析单元尺度对坝后背管混凝土、钢筋的应力影响小于对钢管的影响；坝体与背管混凝土接缝面的力学效应对背管混凝土、钢筋、钢衬的应力影响很小；计算所得的应力大小规律与类似工程模型试验所得的应力分布规律完全一致，其计算值与规范中用弹性中心法所得的应力值基本接近。

Discussion on FEM analysis on penstock structure on the downstream dam surface

In connection with the Lijiaxia project, the stress state of penstock structure on the downstream dam surface is analyzed by aid of the powerful finite element software ANSYS. The results indicate the effect of element dimension on the stress of penstock surrounding concrete and reinforcement is smaller than penstock; the mechanics effect of the joint surface between dam and penstock concrete imposes small influence on the stress of penstock concrete, reinforcement and steel lining; the calculated stress has a conformable distribution law with the model test result of similar project and the calculated value is approximately the same as that of the elastic center method in the Specifications.