Just over two miles of motorway, most of it in tunnels is being built around Stockholm. The blasting work is extensive, and the Swedish Transport Administration benefits from Nitro Consult's experience in other large projects for the control of vibration and noise.

 

It should take a quarter of an hour to drive from Kungens Kurva to Häggvik when the Stockholm Bypass on the E4 is inaugurated in 2030. It is a stretch that today can easily take an hour in rush hour. The gigantic construction project is estimated to cost SEK 28 billion and is in full swing. The main part of the work takes place far down in the mountain. The bypass will be a total of 21 kilometers, of which 18 kilometers in a tunnel. The 16 kilometer long main tunnel is operated from seven different locations. The project therefore includes significant blasting work.

 

- Controlling vibrations and noise from blasting requires specialist expertise. For this work, we hire NCA, a company run jointly by Nitro Consult and Ansvarsbesiktning. They have the necessary experience and training. It is also important that they act independently and in accordance with the current industry standard, says Per Lunde, project manager at the Swedish Transport Administration, who is the developer for Förbifart Stockholm.

 

The NCA conducts pre-, during- and post-blast inspections in the southern parts of the project.

 

- They set benchmarks that the blasting contractor must stay within. The measurements take place continuously and are presented via Nitro Consult's own data system, NCVIB, says Per Lunde.

 

Certain sections of the Bypass Stockholm's tunnels are particularly sensitive to explosions, for example those that run close to the subway in Skärholmen. It has required great accuracy in monitoring vibrations and reporting to the contractor and client. There are also residential properties, data centers, churches, lines and other buildings. For NCA, experiences from Citybanan, the railway through central Stockholm which is now complete, will come in handy.

 

Citybanan was a project in a class of its own when it comes to sensitive surroundings in the form of other infrastructure, culturally-historically valuable buildings, businesses and residences. That's where we started the collaboration with Ansvarsbesiktning. The project gave us valuable lessons that we can apply to ensure how the surroundings are affected in Förbifart Stockholm.

 

In addition to noise and vibration control, NCA is also responsible for third-party management in the Stockholm Bypass project. Nitro Consult has staffed case management from 7:00 a.m. to 10:30 p.m. on weekdays. There, we receive reports of damage and disturbances and handle these according to established procedures. Via NCVIB, we also notify blasts before they are carried out.