关键词: 面板砂砾石坝, 表面止水, 结构改进, 冬季库区结冰, SK刮涂聚脲

Abstract: Nazixia hydropower dam is a concrete face-slab sand gravel dam. It is located in Menyuan county, Qinghai province, a high-altitude and extremely cold area. The surface water stop of the faceslab joint is sealed with SR filler. The EPDM-reinforced SR anti-seepage cover is applied and the water stop is fixed by expansion bolts on both sides. After operation for three years (2015~2017), due to the water freezing in winter, plastic filler on the surface of face-slab joints was extruded along the lower part of plate on both sides, the sealing cover was torn, and the impervious cover had some defects, such as screw loosening and strip warping. This paper introduces the structure improvement scheme for water stop on face-slab joint surface in winter water level variation area, which adopts the scheme of slotted plastic filler + overcoating (SK brush polyurea) water stop. By improvement, the adaptability of surface water stop to the winter water freezing is improved.

Key words: face-slab sand gravel dam, surface water stop, structure improvement, winter water freezing, SK brush polyurea