水电站蜗壳保压浇混凝土结构的三维仿真分析

三峡工程水电站厂房蜗壳采用保压浇外围混凝土的结构形式。为研究钢蜗壳与外围混凝土交界面的接触性态，分别对冬季和夏季浇混凝土情况进行了模拟施工过程的三维有限元仿真计算，给出了交界面在不同季节不同水位运行期的传力和间隙，结果表明温度对传力的影响显著。对冬季浇筑情况，研究了通过提高保压水温来减小高温季节高水位运行期的传力；对夏季浇筑情况，研究了通过降低保压水头来减小蜗壳混凝土在低温季节低水位运行期的间隙。

3-D FEM analysis for surrounding concrete of steel spiral case keeping internal pressure during construction

The surrounding concrete of steel spiral case in the power station of Three Gorges Project is constructed by means of keeping a specific level of internal pressure during construction.For analyzing the contact behavior of the interface between the steel spiral case and its surrounding concrete,the numerical simulations of the construction process during winter or summer season are carried out with 3-D FEM separately.The variation of the gap and the interaction force between the steel spiral case and its surrounding concrete in different opeation stages and different seasons are studied.The calculation result shows that the effect of temperature on the interacting force is significant.The effect of reducing the interacting force in the summer season during high impounding water level by means of elevating the internal water temperature in case of concreting in winter season and the effect of reducing the gap in winter during low impounding level by means of reducing the internal pressure in the case of concreting in summer season are studied.