Geology and Environment

West Metro

The West Metro extension has been one of the most talked about projects in the Helsinki metropolitan area in recent years. The 21-kilometer-long West Metro extension, which includes 13 new stations, has provided work for many design offices.

Rockplan’s Juha Salmelainen was responsible for the principal design of the rock mechanics and tunneling (PS-KAT) for the Ruoholahti – Matinkylä section of the first phase, which was commissioned in 2017. The rock mechanics and tunneling design of the Ruoholahti – Keilaniemi section was the responsibility of the consulting consortium FKW, which consisted of Finnmap Infra, Kalliosuunnittelu Oy Rockplan Ltd and WSP Finland Oy.

In the second phase of the West Metro extension, the Matinkylä – Kivenlahti section, Rockplan is part of the consulting group Sigma and is responsible for the rock mechanics and tunneling design for the Kivenlahti metro station and the structural design for the Kaita station. The Sigma consulting group consists of Finnmap Infra Oy, Kalliositteluittelu Oy Rockplan Ltd, WSP Finland Oy, Sipti Oy and Saanio & Riekkola Oy. Phase 2 traffic is scheduled to begin in 2023.

Stockholm Metro – Blue Line Extension to Nacka

Stockholm metro’s blue line is being extended from Kungsträdgården, with new terminals at Nacka and Sockeplan. The track length of the extension is 11 kilometers, along which 5 new metro stations will be built. Rockplan’s responsibilities in the project include rock mechanical design and engineering geology at Nacka and Sockenplan, as well as engineering geological reports from Gullmarsplan, Sofia, Hammarby Canal and Sickla.

Construction of the blue line extension began in 2019 and the metro is intended to reach Nacka and Sockeplan by 2030.

Kittilä Mine Main Level 900

The design of the maintenance level of the Kittilä gold mine is currently the deepest ongoing project at Rockplan. The new maintenance level, to be excavated and built into the rock, will be located at a depth of 900 meters. The maintenance level will provide warehouse space and social facilities for personnel. In the future, this may be the location of the deepest workplace cafeteria in Lapland!

Sewage Tunnels at the Blominmäki Wastewater Treatment Plant

The sewage tunnels of the Blominmäki Wastewater Treatment Plant consist of an inlet tunnel leading to the treatment plant and a discharge tunnel leading out of the treatment plant. A total of about 20 kilometers of inlet and discharge tunnels and associated access tunnels will be excavated.

In addition to the tunnels, the contract includes maintenance and emergency exit shafts that are critical for safety, the Suomenoja Acceleration and Drainage Pumping Station built within the rock as well as its associated above-ground shaft access buildings, and a challenging connection to the existing offshore tunnel. The offshore tunnel directs treated wastewater 15 kilometers to the sea.

Rockplan was also involved in the general design phase when a suitable site was sought for a new wastewater treatment plant in Espoo. There were five alternative locations under review.

The contracts are estimated to be completed in the summer of 2021. In 2022, the new Blominmäki Wastewater Treatment Plant will treat wastewater from 400,000 inhabitants in the Espoo, Kirkkonummi, Siuntio and West Vantaa areas.

Spent Nuclear Fuel Disposal Facility

The world’s first spent nuclear fuel disposal facility will be built in Olkiluoto, Eurajoki. Spent nuclear fuel is packaged in copper canisters that protect the fuel from mechanical stress for up to 100,000 years.

The disposal facility will be excavated to a depth of 400 meters in the bedrock of Olkiluoto and the disposal canisters will be placed in holes drilled in the disposal tunnels. The stable bedrock provides almost unchanging conditions for nuclear fuel and protects against surface temperature fluctuations.

Excavation work began in 2016 and final disposal of nuclear waste is scheduled to begin in the 2020s.

Watch how it looks like in the depth of 430 meters.

Sulkavuori Central Wastewater Treatment Plant

Construction of the Sulkavuori Central Wastewater Treatment Plant began in 2018 and is expected to be commissioned in 2024. The Sulkavuori Central Wastewater Treatment Plant will be excavated in rock to create stale conditions for the operation of the treatment plant, so that treatment processes are not disturbed or slowed down due to weather variations.

The planned Central Wastewater Treatment Plant uses the latest treatment technologies in order to keep the discharge load on the lake to a minimum. The activated sludge process is supplemented by sand filtration and UV disinfection. The treated wastewater is led to Lake Pyhäjärvi by means of a tunnel excavated in the bedrock and a discharge pipe.

The progress of the excavation of the Sulkavuori Central Wastewater Treatment Plant can be monitored through the environmental monitoring system, EMO (Environmental Monitoring Online), developed by Kalliotekniikka Consulting Engineers Oy.

In the design of the Sulkavuori Central Wastewater Treatment Plant, special attention has been paid to a possible future expansion.