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Using Trimble Tunneling Solutions for Switzerland's Largest Tunnel Project

Constructed below the St. Gotthard Pass in the Swiss Alps, the Gotthard Road Tunnel runs 16.9 kilometers (10.5 miles) between the Italian and German sides of Switzerland. The 10-year construction of the tunnel was completed in 1980, and it has since endured the wear and tear expected for a well-traveled route.

A full closure of the existing tunnel is required for its maintenance, presenting an unacceptable option for this north-south connection. Thus, plans to construct a second tunnel parallel to the first have been put into motion by the Swiss Federal Roads Office FEDRO. This is the largest tunnel project currently underway in the country.

Trimble total station in sisto sud tunnel

A new tunnel and new monitoring equipment

A modern engineering and consulting company, backed by more than 70 years of experience and expertise, the Pini Group is working with Matteo Muttoni Costruzioni SA to build and monitor the expansion of the Gotthard’s SiSto Sud security tunnel. The SiSto Sud provides an outlet from the existing roadway in case of accidents. Once this is fully completed, construction on the second tunnel parallel to the Gotthard Road Tunnel will begin.

Having recently transitioned from Trimble® Italia to the Pini Group, Carlo Bergamaschi was presented with the opportunity to introduce new monitoring hardware and software to his colleagues. “The team has been very enthusiastic about switching to Trimble products,” said Carlo.

The Pini Group is an international, multidisciplinary service company that has expertise in the fields of infrastructure planning, consulting, and construction management. Spektra Srl–the local Trimble distribution partner for the Pini Group–has been delivering Trimble solutions to geomatics professionals for 30 years, and they have played a key role in the Pini Group’s successful implementation of Trimble products.

Several Trimble instruments are being used on the project including the Trimble SX12, S5, and S7 total stations, X7 laser scanner, TSC7 controllers, and TDC600 smartphones. The team is also using Trimble Access™ and Trimble Business Center software. “The Trimble Access Monitoring module is particularly useful as it is robust, user-friendly and helps us save time on the project, particularly for automating the convergence monitoring,” said Carlo.

Carlo and his team, senior surveyors Gabriele Biraghie and Giacomo Longhi, are monitoring the walls around the tunnel blasting/excavation area and gathering convergence measurements for inside the tunnel as construction progresses. They are also conducting tunnel construction stakeout inside and outside of the tunnel, including positioning steel arch ribbing, while providing tunnel construction verification and excavation control for over and undercut analysis using the Trimble SX12 scanning total station.

“Trimble instruments are really robust and can stand up to the challenges presented by the elements, like dust and water,” added Carlo. “And, there is a short learning curve with Trimble Access making it simple for anyone on the team to access the data and analysis they need, when they need it.”

Trimble total station in sisto sud swiss tunnel

The durability and resilience of Trimble instruments and the simplicity of data collection and analysis offered with Trimble Access help address several challenges on the site ranging from maintaining the minimum distances required between the main Gotthard Road Tunnel and the security tunnel, working within tight spaces and short processing times, and drift tracking. There is also a benefit in providing concise communications about the project as teams transition from shift to shift.

When the SiSto Sud is complete, the Pini Group will begin monitoring on a new SiSto project in Switzerland.

To learn more about the Gotthard Road Tunnel project, visit To learn more about Trimble Monitoring products, visit or call your local distributor.