Design and Risk Analyses for the Great Belt East Tunnel

The need to minimise both risk and cost is paramount for large subsea tunnel projects, arguably more than for any other type of construction scheme. Innovative technical solutions often must be sought and developed, tempered with experience and an appreciation of lessons learnt. All such factors contribute to tunnelling technology. The 8 km long twin-bored railway tunnel under the East Channel of the Great Belt forms part of the fixed link between the two main Danish islands of Zealand and Funen. On this project, risk analyses were carried out in great detail, and many recommendations were implemented. Despite this, the project has had its share of difficulties. This highlights the importance of the focus on risk, and on the strict implementation of plans and procedures to minimize the difficulties of tunnelling.