Breaking world records with software from Powel Construction

The E39 Rogfast project is the first large project in Norway’s greatest road project of all time; A ferry-free road between Stavanger in the south-west and Trondheim, around 1000 kilometres driving distance to the north. The project is set to break several world records, amongst them, the world’s longest underwater car tunnel and the deepest four lane road tunnel. The project, not surprisingly, has been met with interest both in Norway and internationally.

Explained briefly, the purpose of the Rogfast project is to build a 27 kilometres long twin-bore tunnel underneath the fjord Bokna, which once completed will replace the current ferry connection. The tunnel will stretch from Randaberg north of Stavanger to Bokn. The project is expected to be approved by the Norwegian government early 2017 and construction is set to begin shortly after.

In the middle of the tunnel, there will be a junction giving road access to the island of Kvitsøy, with entry and exit ramps leading to two roundabouts above the tunnel ceiling height. Furthermore will there be a 3.7 kilometres long spiral-shaped tunnel leading up to Kvitsøy, 250 metres above the E39 tunnels. In addition to the tunnel arm leading to Kvitsøy, roads and bridges will also be built in connection to the tunnel. Once completed, the tunnel will be the world’s deepest road tunnel, with its lowest point at 390 metres below the sea level.  

Statens Vegvesen, the Norwegian Public Roads Administration, is the developer, whilst Norconsult are the consultants for project design of tunnels, roads, and constructions for this complex project. Norconsult utilises the Gemini Terreng software from Powel for the project design.

Comprehensive tunnel system below sea level

On a project of this complexity, there are many issues to consider when projecting. In the same area underneath Kvitsøy where the junction is being planned, a complex ventilation system will also be built. It needs to do the job both during normal day-to-day traffic as well as during emergencies or a fire.

The ventilation system consist of two ventilation shafts measuring ten metres in diameter stretching 255 metres up to Kvitsøy, both for fresh air and extraction. In the tunnel below, a comprehensive tunnel system will lead fresh air to the tunnels and extract the polluted air. Four fans measuring 3.25 metres each in diameter will be placed in two rock caverns which exist within the tunnel system.

The tunnelling system is being designed in BIM (Building Information Modelling) with the help of Gemini Terreng. All the tunnels for the E39 road, shafts, and ventilation tunnels are completely modelled in an interdisciplinary 3D model.

For such a demanding project, sophisticated IT-solutions and partners that can adjust the solutions as necessary is key. Powel develops project functionality together with Norconsult’s experts, who are strategically working towards fully integrated BIM. Their ambition is to free themselves completely from drawings and only use digital models. As such, Norconsult are dependent on having suppliers that can turn around quickly and make required adjustments.

“For us, it is important to have a partner and not just a supplier,” says Torkil Håheim Kind, leader for BIM in Norconsult. “Additionally, it is important that the models we make can seamlessly be transferred directly to the contractor’s systems.”

Complicated engineering

Norconsult has been using Gemini Terreng for some years, but during the last few years the interest and use of Gemini products within the company has grown. Projecting tunnel engineer Hege Anita Eckhoff in Norconsult has been using the Gemini Terreng software for eight years.

“The Gemini solutions are the software solutions we are focusing on. Today, Norconsult has around 30 Gemini users and more and more people are using them for large-scale projects,” says Eckhoff.

Eckhoff is responsible for designing the alignment for the blasting of the tunnel on the Rogfast project. She and the rest of the team are at full speed with their work and she tells a little bit about what sort of challenges they are facing on this gigantic project and how they are utilising Gemini Terreng to overcome the challenges. The junction with associated ventilation shafts and ventilation tunnels inside the tunnel construction comes with very complex solutions that until recently it has been impossible to model.  

“Our main tool is Gemini Terreng, where we use many of the available modules including the tunnel module. About half way into the tunnel there are entry- and exit ramps that meet in a couple of roundabouts. They are connected to each other as well as to a 3.7 kilometres long tunnel arm that leads up to the island of Kvitsøy,” explains Eckhoff. “This junction is at 250 metres below the sea surface and will be the deepest junction in the world! In this area there is also a large ventilation system as well as service tunnels.”

The tunnel module is used both to make mass calculations and to document the tunnel with either manual or parametric descriptions. Norconsult uses 3D visualisation for the ventilation shafts below Kvitsøy. Gemini Terreng also offers possibilities for 3D water and wastewater projecting that will be used during the project. With the 3D terrain model as the foundation, you are able to project water and wastewater pipes where everything is presented in 3D with dimensions on cables and pipes.

“Gemini will also be used in approach zones and tunnels. We may use it for cutting and there is talk of using it for the actual road itself,” says Eckhoff. “Additionally, the solution handles scan and surveying data, and point clouds really well,” says Eckhoff. 

Handling large amounts of data

According to Eckhoff, one of the greatest advantages with the Gemini software is the capacity to easily handle large amounts of data, which provides more opportunities.

“For us, this means that we can communicate seamlessly with the contractor, as the majority of the large contractors in Norway use the same software solutions,” says Eckhoff. “Technically, it is challenging to have enormous amounts of data that we need to handle. We are dealing with long distances here many on the sea bed and on rock and with that comes large amounts of data.”

The Rogfast project itself is estimated to have a construction time of around seven years and the ambition is that within 20 years, a ferry-free western Norway will be a reality. The 1100 kilometre road between Trondheim and Kristiansand today has a journey time of 21 hours which includes seven ferry crossings. Once this entire project is finalised, the travelling time will be cut back with around ten hours.

“With Gemini we plan and project quicker than earlier and what we deliver to the contractor can be used directly in their production. Not only do we save a lot of time, it also creates a more fun working environment for those working on the project,” says Head of the Tunnel division in Norconsult, Jens Petter Henriksen. “We have a good partnership with Powel and they are good at meeting our needs.”

“The key to success for us is that we do not just have a supplier of a standard solution. Powel has acted like a partner, listened to our needs and been good at adjusting our solutions when we have encountered challenges. By being close to our projects, they are helping both us and the industry move forward,” finishes Håheim Kind.