开化水库堆石坝面板湿度和干缩应力研究

Study on the Humidity and Dry Shrinkage Stress of Rockfill Dam Panel for Kaihua Reservoir

为了研究堆石坝施工期的面板湿度和干缩应力,以开化水库面板堆石坝为研究对象,建立不同湿度工况下堆石坝面板有限元模型,对比分析湿度正常工况和湿度突降工况下,面板湿度和干缩应力的时间变化过程。研究结果表明,不施加保湿措施时,2种工况下,面板表面中心点的湿度变化与外界湿度变化基本一致,面板内部点的湿度呈现逐渐下降趋势;施加保湿措施时,2种工况下,面板表面中心点湿度先下降后平缓,面板内部点湿度比不施加保湿措施时略有增大。不施加保湿措施时,面板表面中心点干缩应力呈现先快速上升后平缓的趋势,湿度突降会导致干缩应力突增;施加保湿措施时,面板表面中心点干缩应力波动幅度变小且突增现象消失。

In order to study the humidity and dry shrinkage stress of the panel under different humidity conditions during the construction period of a rockfill dam,a finite element model was established under different humidity conditions with the Kaihua Reservoir panel rockfill dam as the research object.The time-variation process of the humidity and dry shrinkage stress of the panel were compared and analyzed under normal humidity conditions and sudden drop of humidity conditions.The research results indicate that without applying moisturizing measures,under two working conditions the humidity change at the central point of the panel surface is basically consistent with the external humidity change,while the internal points of the panel show a gradually decreasing trend.When applying moisturizing measures,under two working conditions the humidity at the central point of the panel surface first decreases and then stabilizes,while the humidity at the internal points of the panel slightly increases compared to not applying moisturizing measures.When no moisturizing measures are applied,the dry shrinkage stress at the central point of the panel surface shows a trend of rapid increase followed by a gradual stable trend,and a sudden decrease in humidity will lead to a sudden increase in dry shrinkage stress;when moisturizing measures are applied,the fluctuation amplitude of dry shrinkage stress at the central point of the panel surface decreases and the sudden increase phenomenon of dry shrinkage stress disappears.