论文部分内容阅读
为了为聚乙烯管最大水平定向钻孔(ｍａｘｉ-ＨＤＤ)提供安装和设计指南,放置聚乙烯管或导管在碍障物或横跨江河之下的最大水平定向钻孔标准导则ＡＳＴＭＦ1962近日出台。在80年代后期和90年代初期,定向钻孔作为安装聚乙烯管道的方法被广泛采用,由此加速了制定该标准的进程...
To provide installation and design guidelines for the maxi-HDD polyethylene pipes, the Standard Guideline ASTM F1962, Maximum Horizontal Directional Drilling to Place Polyethylene Pipes or Conduits Under Barriers or Across the River, was introduced recently. Directional drilling was widely adopted as a method of installing polyethylene pipes in the late 1980s and early 1990s, thus accelerating the process of developing this standard.