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.

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。

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The dramatic Hollyford Track starts in the midst of lowland forest, crossing mountain streams and passing pretty waterfalls as it follows the broad Hollyford River valley all the way to the sea at Martins Bay.

BBC: New Zealand��s tracks less travelled

John Lasseter relaxes a lifelong disdain of crossing the (franchise) streams, as Disney Infinity reminds him of getting lost in childhood play.

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