天生桥一级水电站溢洪道泄槽裂缝处理与分析

Analysis and Treatment of Cracks in the Discharge Chute of Spillways in Tianshengqiao I Hydropower Station

针对天生桥一级电站溢洪道泄槽的裂缝性状调查及产生原因分析,对不同类型的裂缝提出不同的解决办法。表面裂缝(小于0.2 mm)相对较多,除重点部位需要采取表面覆盖法处理外,其余部位基本不需处理。对较大裂缝(大于0.2 mm)进行长度、宽度、深度调查,研究制定修补方案及施工工艺,施工后进行复查和做好资料整编工作,为以后裂缝处理做好资料储备。在修复施工后,经过10余次泄洪(最大流量为4 900 m3/s)后检查,发现裂缝处理工作总体效果良好,但部分表面抗冲耐磨层又出现破坏,现场分析认为,施工时由于阴雨天较多,底涂层未充分干燥后直接进行表面抗冲耐磨层施工,导致两层层面接合较差,应在以后的加固中予以重视。

In Tianshengiao I Hydropower Station,different type of cracks are found in the discharge chute of spillways.The characters and causes of these cracks are investigated and analyzed. Different treatment measures are then proposed for different type of cracks. For small surface cracks,no treatment is needed except those in key positions which should be treated by the surface shielding method. For large cracks that the width is larger than 0. 2 mm,specific treatment scheme and technology should be applied after a detailed investigation on the crack length,width and depth. Re-examination and data compilation work should be done after the treatment. Practice shows that the crack treatment is generally satisfactory. However,damages are still found in some areas of the surficial abrasion resistance layer. Analysis shows that it could be caused by the bad coherence between the surficial abrasion resistance layer and the bottom coating,as the construction of the surficial abrasion resistance layer is too early before the bottom coating is fully dried.