在中间会面

Drilling a 57-kilometre long tunnel starting from both sides of the mountain and meeting in the middle with barely any deviation was a truly challenging task. Highly precise measuring instruments were needed to successfully accomplish the project.

Measuring down to millimetre accuracy
在隧道网站，调查联盟vi-gbt于1996年开始衡量，当时建造工作开始于20年前。测量工程师使用20个参考点设置基本网络。对于此任务，他们使用总站或光学测量设备以及来自Lebob appleica Geosystems的GPS或GPS或卫星导航解决方案，该公司是一个瑞士根的全球公司以及近200年的传统。

该钻探不仅开始于Erstfeld（北门户）和Bodio（南门户），还开始在三个中间点，侧面通道加入主隧道：Amsteg，Sedrun和Faido。在SEDRUN（1,405米高）中，垂直隧道长800米长到主隧道，所以建筑工人可以从那时起向北方推动北方。

在隧道施工期间，每400米（437.4码）必须重复测量和衡量任务。为了确保隧道正好肯定，测量师必须检查参考点的坐标。此外，还必须使用Leica Geosystems与Leica设备的精确高度测量。

“当我们在2010年10月15日在隧道中间爆发时，两条隧道部分相遇，偏差仅为8厘米或3.1英寸，而25厘米或9.8英寸将容忍，”Ivo Schaetti说：VI-GBT测量工程师。他解释说，由于温度变化，湿度和灰尘，测量隧道非常苛刻。“谢天谢地，我们可以总是依赖Leica Geosystems的测量解决方案的准确性，”Schaetti补充道。“它们非常精确。您可以测量400米的距离，精度小于毫米或0.03英寸。“

Monitoring the dams above the tunnel
During the entire construction period, the surroundings of three artificial lakes above the tunnel required monitoring: Curnera, Nalps and St. Maria. There was a slight probability that the construction of the tunnel – 1.4 kilometres underneath the lakes – would affect the stability of their dams. This monitoring was also done with instruments of Leica Geosystems. The fully automated devices monitored the dams throughout the entire tunnel construction from 2000 until 2015.

“总站监控bob apple最微小的动作of the prisms that were mounted near the dams,” says Falko Henning, Leica Geosystems product manager. “Happily, no unusual movements occurred.” There was no major delay during construction time, and the tunnel will be inaugurated as planned.

瑞士传统
莱卡地铁系统在瑞士有丰富的历史。从它的起源于与凯恩和公司成立于1819年的阿雷劳，今天的衡量技术的行业领导者在许多段中为客户提供全球服务，包括工程，建筑和采矿。

“Looking back on a tradition of nearly 200 years, we’re honoured to once again take part in a significant milestone in Swiss history by providing the surveying and monitoring resources to successfully open the Gotthard Base Tunnel,” said Juergen Dold, Leica Geosystems CEO. “With a commitment to Swiss quality and a global outlook, we will continue to innovate and support professionals around the world achieving feats of engineering like this tunnel.”