某高拱坝在不同施工模拟方式下的应力状态
2021-08-11张舒楠陆晓敏
张舒楠 陆晓敏



摘 要:以某高拱坝为例,首先用线弹性有限元法分析自重荷载施加方式如何影响大坝整体的应力场分布,提出采用分层浇筑和灌浆施工的坝体自重宜分步施加,其数值模拟结果更符合实际;然后考虑了静水压力的施加过程以及温度荷载对拱坝应力的影响,得出了静水压力施加方式对应力影响不大,而温升、温降对坝体应力影响较大;最后利用非线性有限元法分析了施工过程对坝体塑性区分布及塑性应变的影响,得出了在非线性模型中自重一次施加时坝体的损伤最大。
关键词:拱坝;施工过程;加载过程;应力状态
中图分类号:TV642.4 文献标志码:A
doi:10.3969/j.issn.1000-1379.2021.07.030
引用格式:张舒楠,陆晓敏.某高拱坝在不同施工模拟方式下的应力状态[J].人民黄河,2021,43(7):154-159.
Abstract: In view of a high arch dam, first of all, the linear elastic finite element method was used to analyze how the gravity loading method affected the overall stress field distribution of the dam. Then it considered the applying process of hydrostatic pressure and temperature loads on arch dam stress, the influence of the hydrostatic pressure was little to the stress and temperature had a greater influence to the temperature drop to dam stress. In the end, the nonlinear finite element method was used to analyze the impact of the construction process on the plastic area of the dam and the size of the plastic strain and it had to be the most damaging to the dam in the nonlinear model.
Key words: arch dam; construction process; loading process; stress performance
拱壩[1-2]是一种既安全又经济的坝型,它不仅能够有效节省工程量,而且能利用有利的河谷形态和两岸基岩来承受巨大的水平推力,形成很好的受力条件,但是拱坝自身特殊的空间壳体结构和复杂的几何形状等特点,导致其在施工期和运行期受力体系和结构状况都比较复杂。
混凝土拱坝的施工一般是分期分块浇筑,在施工和蓄水过程中,拱坝的实际承载结构会随着坝体施工过程而不断变化。传统的结构力学计算方法通常假定自重全部由悬臂梁承担,而使用有限元方法[3-6]计算时,为了简化计算,大多假定拱坝形成后,自重一次性施加于整个坝体,拱梁共同承担自重。但实际上拱坝在接缝灌浆前自重全部由梁承担,接缝灌浆以后再浇筑坝体的自重由梁与拱共同承担,因此灌浆过程对应力分布有很大影响。……
