Rock builder excavates and reinforces

Text: Helen Partti

When traveling along highways and looking at rock cuts at large road construction sites, everyone probably wishes that boulders wouldn’t fall off the walls. However, sometimes it does, which can be dangerous. For example, last summer, boulders detached from a rock-cut fell onto Ring III. Fortunately, personal injuries were avoided.

Vantaa-based JIITEE Työt was alerted to the scene, and after a careful investigation, a rock construction professional reinforced the rock to make it durable and safe.

Founded in 2011, JIITEE Työt Oy specializes in reinforcement work. In 2022, the company expanded its operations significantly by buying Pohjolan Kalliotyö Oy, which specializes in underground mining.

As a result of the merger, JIITEE Työt can now offer large service packages from excavation to reinforcements and renovations. Work sites vary from rock cutting for roads and railways to tunnel excavation and renovation. Among the objects are, for example, vertical shafts, parking garages, and sewer tunnels.

Professionalism can be seen in challenging jobs.

Behind the neat underground shaft wall hides a large amount of excellence in rock construction.

First, a shaft, according to the plans, is made in the rock by quarrying, drilling, or wire sawing. Then, the surface of the shaft is finished by roughing out the loose stones.

Next, holes are drilled in the excavated shaft, where reinforcing bolts are installed with solder cement. After this, shotcrete barriers are installed to control water leaks. If necessary, a reinforcing mesh is also installed, after which the surface is finished with shotcrete.

In reinforcement work, JIITEE Työt is number one in its field

– We have done over 250 shaft reinforcement works during the last few years, says manager Janne Juntunen.

In 2021, JIITEE Työt finished strengthening the bottom of the kilometer-deep shaft of Europe’s largest gold mine in Kittilä. At the Parainen mine, the company excavated and reinforced a 340-meter tunnel. JIITEE Työt was also involved in constructing the world’s first nuclear waste facility’s capsule shaft. A similar target cannot be found elsewhere.

The specialist in rock construction has also done the drilling, water penetration, and grouting work for the foundations of more than 200 windmills.

– We have precisely the kind of drills and grouting equipment the job requires. Yes, our handprints are already starting to be seen in them, Juntunen states.

Currently, JIITEE Työt is working on a project related to the sewer tunnel in the center of Helsinki. We are excavating a tunnel underground in the middle of the city where existing sewer, service, and metro tunnels make it challenging. All kinds of vibration and the surrounding buildings must be taken into account when thinking about, for example, time windows for explosions, Juntunen says.

JIITEE Työt also faced exceptional challenges recently in renovating the sewage tunnel between Koivuhaa and Harjusuo in Central Uusimaa. The project was particularly demanding because the renovation was carried out at the same time as the sewer tunnel was in use. The site required the highest level of protective equipment and multi-gas meters for continuous air quality monitoring.

Committed and motivated personnel guarantee quality

Rock construction requires personnel not only to have solid professional skills but also to have a strong ability to withstand pressure and to work hard. The employer, on the other hand, has to react with the fastest movements to different types of situations: Even Ring Road III could immediately take corrective measures.

– We can quickly organize personnel for different tasks. We know our employees exceptionally well because they have worked for us for many years. The staff turnover in the company is also low, says operational director Lassi Levaste.

When employees know each other, they also get along in demanding working conditions.

– In reinforcement and excavation work, it is extremely important that the employees’ motivation is in order. Otherwise, things will not progress.

The rock builders move geographically to very different types of sites. The working conditions are demanding, and the work shifts can sometimes be lengthy.

– Must do high-quality work in harsh working conditions under heavy pressure. Employees must commit to the company. We have an outstanding culture of working together, concludes Levaste.