基于复合单元法的含层面碾压混凝土坝温度场研究

Research on Temperature Field of RCC Dam Containing Lift Interfaces by Composite Element Method

基于复合单元法的基本原理和不稳定温度场的隐式解法,推导了含有层面的混凝土温度场分析复合单元法控制方程。该算法可以离散模拟碾压混凝土坝中的层面,又避免了剖分层面网格的繁琐的前处理。除此之外,该算法还能整合到传统的有限单元分析程序中,如果某单元不含层面时,它将自动退化为传统的有限单元。基于该算法,建立了老挝南俄5碾压混凝土重力拱坝三维复合单元模型,进行了三维瞬态温度场仿真计算,计算值与监测值在规律和量值上吻合较好。研究结果表明该算法的合理性和在工程应用中具有实用性。

According to the principle of composite element method （CEM） and the implicit expression of transient temperature field, the thermal governing equations of CEM for mass concrete containing lift interfaces are deduced. The effect of each lift interface can be well simulated and the difficulty of generating meshes around the lift interface is overcome. This algorithm can be incorporated into the conventional finite element analysis program. The element containing no lift interface will be degenerated to traditional finite element automatically. By using this algorithm, a three-dimensional composite element model of Laos Nam Ngum5 RCC gravity dam is established. The three-dimen- sional transient temperature field is simulated. The computational results agree with the monitored values very well in terms of variation regularity and quantity. The research results indicate that this algorithm is valid and practical in engineering application.