Abstract: This paper analyses the cause of doubtful point on deformation which has great difference between the horizontal displacement values on the crest of the No.9 dam block measured by plumbline of PL and collimating line of AL6 from the view of observation error and temperature-loading. It indicates that the main cause of these difference, through measurement of height difference on those two points and horizontal distance change, are contributed to the upper pier concrete deformation developed as the temperature changed and accumulated to the pier end, then result in the measurement difference between those two points on the top of pier.

摘要： 本文从观测误差和温度荷载因素，分析了石塘大坝9#坝段正垂线PL测点与视准线AL6测点所测得的坝顶水平位移存在较大差异这一变形疑点的成因，并通过实测这两点高差和平距的变化，分析说明了产生差异的主要原因是闸墩上部混凝土随温度变化产生自由涨缩变形，并向闸墩端部积累，从而导致了位于闸墩顶部不同位置两点间的测值差异。?