Opening the world’s longest, deepest rail tunnel with precise measurement

Author: Staff,October2016

Surveying and monitoring systems made the construction of the Gotthard Base Tunnel in the Swiss Alps possible. The tunnel was inaugurated June 1, and the breakthrough on October 15, 2010 was due to highly precise surveillance and monitoring technology. The 57-kilometre long tunnel is the longest and deepest rail tunnel in the world.

从山的两侧开始钻一条57公里的长隧道，几乎没有任何偏差在中间会议，这是一项真正具有挑战性的任务。需要高度精确的测量工具来成功完成该项目。

Measuring down to millimetre accuracy

At the tunnel site, the surveying consortium VI-GBT started measuring in 1996, when construction work began 20 years ago. The surveying engineers set up a basic network with 20 reference points. For this task, they used total stations, or optical measuring devices, and GPS, or satellite navigation solutions from Leica Geosystems, a global company with Swiss roots and a tradition of nearly 200 years.

钻井不仅在埃斯特菲尔德的北门户网站和Bodio的南门户网站开始，而且还在三个中间渠道加入了主隧道：Amsteg，Sedrun和Faido。在Sedrun（1,405米）中，将800 m长的垂直隧道向下钻到主隧道，以便建筑工人可以从那时起向北和向北。

在隧道施工期间，必须每400米重复测量和测量任务。为了确保隧道准确地符合过程，测量师必须检查参考点的坐标。此外，还必须使用级别的设备（也是从Leica Geosystems）测量的确切高度。

“When we broke through in the middle of the tunnel on October 15, 2010, the two tunnel sections met with a deviation of only 8 centimetres, whereas 25 centimetres would have been tolerated,” said Ivo Schaetti, a surveying engineer at VI-GBT. He explains that surveying tunnels is very demanding due to temperature changes, humidity and dust.

“Thankfully, we could always rely on the accuracy of the surveying solutions from Leica Geosystems,” Schaetti adds. “They are very precise. You can measure a distance of 400 metres with accuracy of less than a millimetre.”

Explore next chapter:监视隧道上方的大坝

故事：开放世界上最长，最深的铁路隧道，并精确测量
Chapter 1: Measuring down to millimetre accuracy
Chapter 2:监视隧道上方的大坝
Chapter 3:A swiss tradition