通过工程实例，介绍水平定向穿越敷管施工工艺和技术要求，借以说明该技术的优点。
By project case, the paper shows advantages of horizontal directional crossing pipelaying by its construction process and technical requirements.
水平定向钻孔(HDD)常常是管道穿越河流或湿地这类障碍优先选用的方法。插图表示河流穿越的典型情况。
HDD is often the preferred method for constructing the pipeline across such obstacles as streams or wetlands. (See inset diagram.) Here is shown a typical river crossing.
在水平定向钻穿越管道回拖环节中，容易出现卡管现象，导致穿越失败，造成巨大的经济损失。
Pipe sticking phenomenon appears sometimes during pull-back stage of pipeline crossing with horizontally directional drilling, which results in crossing failure and great economic loss.
在水平定向钻穿越管道回拖环节中，容易出现卡管现象，导致穿越失败，造成巨大的经济损失。
Pipe sticking phenomenon appears sometimes during pull-back stage of pipeline crossing with horizontally directional drilling, which results in crossing failure and great economic loss.
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