Introduction

The population in western Sweden is growing rapidly, putting immense pressure on Gothenburg’s infrastructure, which is currently unable to keep up with the increasing demands. As a result, the Swedish government decided to invest in a new initiative: The West Swedish Agreement (Det Västsvenska Paketet). This is one of the largest investments ever made in public transport systems, aiming to enhance geotechnical and rail tunnel construction, railways, roads, rail bridges, and cycle paths.

Project Background

One of the largest projects in the West Swedish Agreement is the construction of the West Link (Västlänken), a dual-track rail tunnel running below the center of Gothenburg. Once completed, it will double the number of trains per day. Three new stations will be constructed at Gothenburg Central, Haga, and Korsvägen, reducing pressure on overground transport and shortening travel times for passengers.

The West Link will intersect the Göta Tunnel (Götatunneln) at Kanaltorget and Otterhällan. To withstand the increased traffic, reinforcement measures are necessary. The consortium AGN Haga is responsible for the construction work on the Göta Tunnel, a challenging geotechnical project due to its deep excavation pits in a complex urban area. Even the smallest structural changes can impact the stability of both the road and the railway running above it.

Challenges

The Göta Tunnel is a tunnel in central Gothenburg, constructed between 2000 and 2006. To this date, it remains one of the most challenging geotechnical construction projects in Gothenburg due to its deep excavation pits in a complex urban area. The complexity of the Göta Tunnel is not to be underestimated. Even the smallest changes in the structure can impact the stability of not only the road passing through the tunnel but also the railway running on top of it.

Solution

To ensure the stability of the Göta Tunnel during rail construction, AGN Haga has implemented a condition monitoring solution. The consortium has installed prisms on-site and requested Railmonitor to deliver a remote monitoring solution as well. Railmonitor provided wireless optical displacement tilt sensors, installed in the tunnel’s ceiling, to automatically monitor vibration and settlement. The TrackBed³⁶⁰ monitoring solution features the latest technology for condition monitoring, enabling AGN Haga to monitor the construction process and its effects on the surrounding infrastructure 24/7.

The Digital Service Platform

Data from the sensors is stored directly in Railmonitor’s Digital Service Platform. Any irregularities or limit value exceedances are detected by the software. If any thresholds are exceeded, the system automatically notifies AGN Haga, allowing the consortium to halt construction immediately until the issue is resolved.

Benefits

By leveraging Railmonitor’s advanced digital monitoring solution, AGN Haga ensures the safety and stability of Gothenburg’s Göta Tunnel, setting a new standard for infrastructure projects within the West Swedish Agreement. This innovative approach not only improves the longevity and stability of the railway infrastructure but also enhances maintenance efficiency by enabling condition-based and predictive maintenance.

Conclusion

The implementation of Railmonitor’s monitoring solution has proven to be a critical component in managing the complex rail construction of the Göta Tunnel. This collaboration not only safeguards the existing infrastructure but also contributes to the successful realization of the West Swedish Agreement, ensuring a robust and efficient public transport system for Gothenburg.

About AGN Haga

AGN Haga is a consortium consisting of Astaldi Group, Gulermark Heavy Industries Construction & Contracting, and NRC Group. The consortium is responsible for the construction work on the Göta Tunnel, leveraging their combined expertise to tackle one of Gothenburg’s most challenging infrastructure projects.