Abstract: The Longshou II hydropower project is a steel concrete face slab rock- filled damwith a maximal height of 146.5 m. It is located in high rate earthquake area and the valley is dissymmetrical whose width- to- height ratio is 1:1.3. The climate here is extremely cold and dry, with a wide range of temperature variation between day and night. Because of special topographical condition, the face slab undergoes tensile pressure that higher designing requirement of crack resistance of face slab is put forward. According to the particularity of this project, the aspects such as dam type, construction parameters selection of dam material and design for different damblocks were researched and relative measures were taken to reduce cracks. For some face slab, concrete mixed with steel reinforcing bar and steel fibre were adopted (the vertical steel reinforcement ratio was 0.4%, the lateral steel reinforcement ratio was 0.35% and the fibre dosage of Dramix RC- 80 /60- BN steel was 35 kg/m3). In the second stage, besides steel fibre, polypropylene fibre concrete was adopted (the vertical steel reinforcement ratio was 0.4%, the lateral steel reinforcement ratio was 0.35% and the fibre dosage of polypropylene is 1 kg/m3)in construction to control cracks on face slab.

摘要： 龙首二级(西流水)水电站工程大坝为钢筋混凝土面板堆石坝, 最大坝高146.5 m。坝址位于高寒高地震区且河谷极不对称, 河谷宽高比为1∶1.3, 气候寒冷干燥, 昼夜温差大,在全国面板坝中其地形条件特殊, 坝体、面板受力复杂, 这对面板的抗裂设计提出了较高的要求。针对该工程的特殊性, 设计从坝体的体型、坝料的填筑参数选择、坝体分区设计等方面对预防面板产生裂缝或减少裂缝进行了研究并采取了相应的措施, 对部分面板采用了钢筋和钢纤维“双掺”混凝土的复合设计方案( 纵向钢筋配筋率0.4%, 横向钢筋配筋率0.35