一、前言陈村大坝在坝顶采用了三种观测水平位移的方法,经过多年的观测实践,认为大坝的视准线观测比三角网法、前方交会法具有施测简单、计算方便、直观等优点,能迅速得出观测结果,及时掌握大坝运行状态。目前设置了四条视准线(其中一条是临时视准线)基 I. Introduction Chencun dam has adopted three kinds of methods for observing horizontal displacement at the crest. After years of observation and practice, it is considered that the dam’s sight line observation is more simple than triangulation method and forward intersection method, so calculation is convenient. Intuitive and other advantages, can quickly come to observation results, timely grasp of dam operation. Currently, four lines of sight (one of which is a temporary line of sight) are set