由于坑内潮湿和顶板滴水,测量工作常用的金属桩子,往往因日久生锈,寿命不长,造成人力、物力和时间上的浪费,影响测量成果的精度,不能及时提交资料。为了解决这个问题,我们改用硬质塑料桩(聚氯乙稀),生产实践证明,可以满足坑内测量工作的要求。它具有:质硬、不脆、耐酸、耐碱、不变形、安装迅速、制造简单、成本低(以10毫米厚的塑料板计算,每桩重70克,价值3角) Due to the moisture in the pit and dripping water on the roof, the metal stakes commonly used for measuring work are often rusty and have a short life span, resulting in the waste of manpower, material resources and time, affecting the accuracy of measurement results and failing to submit information in time. In order to solve this problem, we use rigid plastic piles (polyvinyl chloride), production practice has proved that it can meet the requirements of pit measurement. It has: Hard, not brittle, acid, alkali, deformation, rapid installation, simple manufacture, low cost (10 mm thick plastic board calculation, each weighing 70 grams, the value of 3 angle)