水电站充水保压蜗壳结构仿真分析

Simulation and analysis of preloaded-filling spiral case in hydropower station

应用面-面接触非线性理论,考虑钢蜗壳与外围混凝土的接触滑移,分别对断面直径大小不同的轴对称充水保压蜗壳模型进行了施工、逐级加压过程的仿真计算,主要对钢蜗壳打压后的变形、蜗壳与混凝土的间隙及其应力变化过程三方面进行研究。计算结果表明,若蜗壳断面直径较大,水重对钢蜗壳打压后的变形以及逐级加压过程中钢蜗壳与外围混凝土的间隙变化过程影响较大,但对应力变化影响较小;若蜗壳断面直径较小,水重对上述三方面的影响都很小;无论蜗壳断面直径大小,是否考虑蜗壳与支墩的接触滑移对上述三方面的影响都较大。

Surface-to-surface contact nonlinear theory was applied to the contact slippage between spiral case and surrounding concrete and two axisymmetric FEM models have been developed for preloaded-filling spiral case of different cross-sectional diameters.By simulating all courses of the construction and successive pressurizing,this study focuses on three factors,deformation of steel spiral case under preloaded filling pressure,gap value between spiral case and its surrounding concrete and their stress variations.The result shows that if the diameter is large,water weight has great impact on the case deformation and the variation of gap value,while little impact on the stress variations.If the diameter is small,water weight has little impact on the three factors.Whatever the diameter large or small,consideration of the contact slippage between spiral case and its surrounding concrete is crucial to the results of three factors.