高拱坝迎水面聚脲涂层防渗结构动力变形性能试验研究

为研究高拱坝坝体表面增加聚脲防渗涂层在地震作用下的动力变形性能,以西南地区某高拱坝上游面聚脲防渗体系为研究对象,在圆柱体全级配混凝土试件表面喷涂聚脲涂层作为基础试件,采用MTS 15MN大型动态材料试验机,模拟坝体在地震作用下的横缝或裂缝瞬时张开工况,测试不同厚度聚脲涂层和不同结构形式横缝表面止水结构的动力变形性能。动力变形试验结果表明,在坝体混凝土横缝或裂缝瞬时张开时,聚脲涂层在一定开度范围内表现出柔性特性。模拟横缝动力变形试验结果表明,采用双峰结构型式的表面止水结构适应横缝大变形能力好,可推荐作为高震区拱坝横缝表面有效的止水结构型式。

Experimental study on dynamic deformation behavior of polyurea coating anti-seepage structure for upstream face of high arch dam

In order to study the dynamic deformation behavior of the enhanced polyurea anti-seepage coating for the surface of high arch dam under seismic effect， the polyurea anti-seepage system of the upstream face of a high arch dam in the Southwest China is taken as the study object， and then the instantaneous opening statuses of the transverse joints or cracks on the dam body under seismic effect are simulated with the MTS 15MN large dynamic material testing machine by taking fully graded cylindrical concrete specimen with the surface polyurea coating as the basic specimen， from which the dynamic deformation behaviors of the surface water-stopping structures of the transverse joints with various thicknesses of polyurea coatings and various structural forms are tested. The result of the dynamic deformation experiment shows that the polyurea coating presents a flexible behavior within a certain opening range during the instantaneous opening of the transverse joint or crack of the dam concrete. This indicates that the surface water-stopping structure of bimodal structural form is better adaptable to the large deformation of the transverse joint， thus can be recommended as an effective water-sopping structure for the transverse joint surface of high arch dam in high intensity seismic region.