大型水电站充水保压蜗壳结构联合承载分析

Joint Bearing Analysis for the Preloading Water-filled Spiral Case of Lager Hydropower Station

蜗壳结构是电站厂房的核心结构物，因此准确获取其应力、应变状态是至关重要的。通过数值计算，采用简化算法对某水电站保压蜗壳结构进行了应力状态和变形情况分析，并与直埋方案做了对比研究，结果表明：从限裂方面考虑保压蜗壳结构有利于机组的安全稳定运行，该水电站采取充水保压埋设方式是合理的；蜗壳外围混凝土各截面最大拉应力值出现在蜗壳顶部，该机组设计保压值偏低，选取1．9MPa保压值比较合理；蜗壳外围混凝土的结构应力值主要是由内水压力所引起的，上部荷载影响很小，仅占5％～24％左右。

Spiral case is the core structure of powerhouse, therefore, it is critical to obtain its accurate stress and strain. Simplified algorithm is adopted to analyze the mechanical characteristics of preloading water- filled spiral case of a large hydropower project. The numerical results show that the adoption of preloading water-filled spiral case structure is feasible. The maximum stress of surrounding concrete mainly lies in the top of spiral case structure at various sections. The suitable internal pressure is 1. 9MPa. The stress of surrounding concrete of spiral case is mainly caused by water pressure, and the effect of upper loading is limited,which is only about 5% to 24%.