丰满混凝土重力坝垂直位移的定量分析

<正> 混凝土坝顶部的垂直位移,主要受温度变化时材料热胀冷缩的影响。当坝体混凝土温度场已经稳定只随季节变化时,坝顶高程一般都是夏秋上抬,冬春下降,在一定变化范围内作周期变动。但是四十年代投入运用的我国东北丰满重力坝(图1),其坝顶垂直位移却出现了一种特殊情况:从1959年开始系统观测到1979年二十年间,左岸坝段和河床坝段抬高了

The Quantitative Analysis of the perpendicular Deflection of the Fengman Concrete Gravity Dam

Some changes of perpendicular deflection of a concrete dam in cold zone are very complex. This paper introduces an example performing quantitative analysis for the perpendicular deflection of the Fengman Gravity Dam and explains how to work out mathematical models, preliminarily choose factors, calculate regressioa equation and analyse the results. By means of this analysis, the writer discovers that the perpendicular deflection of the concrete dam which is situated in cold zone and has many horizontal cracks filled with water is affected not only by swelling under heat and shrinking under cold but also by swelling by the ice within the cracks. These "freezedeflections" on some blocks of the dam are so great that they top the normal deflections and become primary factor. Some of the freeze-deflections are permanent deflections, which will increase gradually, thus reducing the safe service life of the dam. Therefore, this problem deserves to be properly noticed. The analysis drawn from the calculation reveals the cause of the unusual phenomenon which has been existing for many years on the Fengman Dam indicates the harmful effect of the ice damage on it. Effective measures should therefore be taken to control the further development of the existing defects.