寒冷强震地区250 m级特高混凝土面板堆石坝接缝止水设计

Joint Waterstop Design for 250 m Ultra-high Concrete Face Rockfill Dams in Cold and Seismically Active Regions

寒冷强震地区的250 m级特高混凝土面板堆石坝变形控制难度大、抗震安全问题突出、耐久性要求高,这些难题对面板坝接缝止水设计提出了更高的要求。以233.5 m高的玉龙喀什混凝土面板堆石坝为例,利用三维静动力有限元计算成果,结合国内外类似高面板坝的工程经验,定量提出其接缝变形控制标准,针对性地开展了不同部位接缝的止水尺寸设计。基于工程特点和大坝变形特性,考虑面板不同区域受力的差异、水位变动区冰冻的影响、防挤压破坏和板块间约束等因素,采用多道冗余设计、聚脲涂覆盖板、垂直缝均设嵌缝材料、压性缝局部加强等措施,对周边缝、垂直缝、防浪墙水平缝和沉降缝的止水开展了个性化设计,可供类似工程参考。

Deformation control,seismic safety,and durability present significant challenges for 250 m ultra-high concrete face rockfill dams(CFRD)in cold and seismically active regions.These challenges necessitate an elevated standard for waterstop design.Using the 233.5 m high Yulongkashi CFRD as a case study,this paper quantitatively proposes a joint deformation control standard based on the results of 3D static and dynamic finite element analysis,in conjunction with relevant engineering experiences.In addition,a tailored waterstop size design is carried out for different joints.Considering the unique characteristics of the project and dam deformation,factors such as varying stress distribution across the dam face,the impact of freezing in fluctuating water levels,prevention of extrusion failure,and interplate constraints are taken into account.Measures such as multi-channel redundant design,polyurea coating for covering plates,incorporation of seaming materials in vertical joints,and localized reinforcement of compressive joints are employed in the customized design of waterstops for perimeter joints,vertical joints,horizontal joints of the wave wall,and settlement joints.These findings serve as valuable references for similar projects.