混凝土蜗壳结构在运行中承受复杂荷载作用时容易开裂,由于裂缝的产生,蜗壳防渗设计是一个需要重点关注的问题。鉴于混凝土蜗壳在中低水头甚至高水头电站中将得到更多的应用,而目前对混凝土蜗壳防渗问题的研究还不充分,结合某河床式水电站工程实际,运用三维非线性有限元方法对混凝土蜗壳的多种防渗方案进行了研究。研究表明:高强混凝土、钢纤维混凝土和环氧砂浆方案能解决混凝土蜗壳结构的限裂问题,但实践中有较大的局限性,而在蜗壳混凝土内表面设钢衬以及预应力加固方案的防渗效果较好,建议在实际工程中优先采用。

Cracks are very likely to occur due to complex loads endured by concrete spiral case during the operation of hydropower station. Seepage control design is hence a big problem needs focus. Owing to insufficient research of seepage control at present and more applications of concrete spiral case in low and middle and even high head power stations in the future, some seepage control measures for concrete spiral case were analyzed by nonlinear finite element method with a hydropower station in river channel as the research background. The research results indicate that high strength concrete, steel fiber-reinforced concrete and epoxy mortar materials could solve the cracking problem for the concrete spiral case structure, but they have some limitations in practice. Steel liner coating on the inner wall of concrete spiral case and pre-stressed reinforcement have good effect in dealing with seepage problem and they are recommended to be preferentially used in practical projects.