渗透溶蚀作用下混凝土坝质量损失分布规律

Distribution law of concrete dam mass loss under seepage erosion

针对渗透溶蚀作用下混凝土坝固相钙的分解问题,基于水泥基材料渗透溶蚀分析模型,提出了混凝土坝溶蚀质量的计算方法,并以石漫滩水库重建工程碾压混凝土重力坝为例,研究了大坝不同部位的溶出质量分布规律。计算结果表明:仿真结果与监测数据吻合良好,验证了该方法的正确性;石漫滩水库重建工程碾压混凝土重力坝胶凝物质溶出部位集中在面板底部、齿墙的上游侧以及帷幕和齿墙连接部位;排水管的存在会影响胶凝物质溶出速率,经过100 a的溶蚀,帷幕、齿墙、面板和坝体的溶蚀胶凝材料质量占结构总质量百分比分别为5.5%、5.6%、4.5%和1.2%,说明渗透溶蚀作用对帷幕和齿墙的影响较大,在工程运行中,应加强对帷幕和齿墙溶蚀情况的监测。

Aiming at the problem of solid calcium decomposition under seepage erosion of concrete dams, based on the analysis model of cement-based material advection-diffusion-driven leaching model, the calculation method for concrete dam leaching quality was proposed. Taking the RCC gravity dam of the Shimantan Reservoir as an example, the distribution of the leached quality of different dam sections was studied. The calculation results show that the simulation results are in good agreement with the monitoring data, which verifies the correctness of the method. The leached parts of the dam cementitious materials are concentrated at the bottom of the concrete face slabs, the upstream side of the key-wall and the connection part of the curtain and the key-wall. The existence of the drainage pipes can affect the leaching rate of the cementitious materials. After 100 years of leaching duration, the mass percents of the cementitious materials of the curtain, key-wall, panel and dam body are 5.5%, 5.6%, 4.5% and 1.2% respectively, which shows that the advection-diffusion-driven leaching has a great impact on the curtain and the key-wall. In the operation of the project, it is necessary to strengthen the leaching monitoring of curtain and key-wall.