News

Safety plans were appropriate in blasting operations that led to accident at Kivenlahti

On 29 July at 9 am, rocks flew into nearby properties during the construction of water and sewage connections near the Kivenlahdentori metro station entrance. The rocks broke 13 windows in nearby properties. No one was injured in the incident. Fire water and household water pipelines and rainwater and wastewater sewer pipelines and their wells are being constructed for the city of Espoo, near the metro entrance. In addition, a new district heating pipeline is under construction. Despite the safety precautions taken during the open excavation, some rocks hurtled into the nearby properties.

-The safety plan for the excavation work was drawn up appropriately. The individual performing the blasting operation had been familiarised with the work site and had the legal qualifications required to perform the work, and this was verified prior to the work being started. An investigation by authorities to determine the cause of the accident has been initiated but is not yet complete. Skanska is assisting the authorities in determining what caused the accident. The damage to the nearby properties will, of course, be repaired,” says Regional Director Pekka Räsänen of Skanska Infra, the contractor at the work site. “This type of accident is very rare in blasting work,he adds.

The company that carried out the blasting operation was a subcontractor of Skanska.

Excavation work is subject to strict liability. The excavation contractor is always liable for their own work. Excavation work is carried out in compliance with the Council of State Ordinance concerning safety during blasting and excavation operations and the Government Decree on the Safety of Construction Work. Every blasting operation is planned in advance. Excavation work is always performed by an individual who holds the qualification of blaster. A security guard is present during blasting to prevent anyone from entering the area and the vicinity. Warning sirens are also used in excavation operations. In open excavation, blasting mats are used to prevent rocks from flying into the surrounding environment. The force of each blast is recorded in a vibration meter.

-The West Metro will be the world’s safest metro. The safety of the employees working on the project and the area surrounding the work site is also a priority for us. We demand strict compliance with laws and guidelines from everyone working on Länsimetro’s work sites. We are one of the largest developers in Finland, and we aim to promote a strong culture of occupational health and safety in the construction industry, stresses Länsimetro Oy’s CEO, Ville Saksi.

Blasting on the work site was completed last week. Concrete and reinforcement work as well as technical building services work is currently under way at the Kivenlahti metro station. The construction work is moving forward normally. Excavation work on the West Metro’s stations and tunnels ended in 2018.

Further information:

Ville Saksi, CEO, Länsimetro Oy, tel. +358 (0)40 823 2086, ville.saksi(at)lansimetro.fi

Pekka Räsänen, Regional Director, Skanska Infra Oy, tel. +358 (0)40 574 6582, pekka.rasanen(at)skanska.fi

Trench excavation at Seitsenmerenreitti in Kivenlahti completed

The trench excavations that were part of Länsimetro’s Kivenlahti construction contract have reached completion.

The reason for the excavation is because of the construction of water and sewer lines on Seitsenmerenreitti. They are related to both the Kivenlahti metro station’s water and sewer connections and to the public utility lines to be constructed for the City of Espoo. Fire water and household water pipelines and rainwater and wastewater sewer pipelines and their wells are being constructed for the city. In addition, a new district heating pipeline is under construction.

Work on water and sewer connections and district heating for the Kivenlahti metro station and public utility work for the City of Espoo will be completed by the end of October.

We apologise for any inconvenience that the work may cause.

Further information:

On-call phone line, Skanska Infra Oy: +358 (0)50 402 3044
Länsimetro’s feedback line (Mon–Fri, 9 am to 3 pm): +358 (0) 50 377 3700

 

Open excavation accident at Kivenlahti causes 13 windows to break

On 29 July at 9 am, rocks flew into nearby properties during the construction of water and sewage connections near the Kivenlahdentori metro station entrance. Fire water and household water pipelines and rainwater and wastewater sewer pipelines and their wells are being constructed for the city of Espoo, near the metro entrance. In addition, a new district heating pipeline is under construction. Despite the safety precautions taken during the excavation of the pipeline trenches, some rocks hurtled into the nearby properties.

In a residential building located three metres away from the open excavation area, a total of five windowpanes broke in windows or balconies. In a partially empty commercial building next door, and 25 metres from the construction site, eight windowpanes broke. The contractor has met with the residents and agreed on repairs. The repair of the windows in the commercial building will be agreed on with the building’s manager.

Before the open excavation, passage to the area was restricted. During blasting, the security guard does not allow anyone to enter the area. In open excavation, areas to be blasted are carefully covered with blasting mats. In this case, too, blasting mats were in place. Despite the precautions taken, some rocks blasted out from under the mats.

When the accident happened, the contractor immediately isolated the area, ensured that no one was injured and contacted the residents. An investigation into the cause of the incident is ongoing.

Concrete and reinforcement work is under way at the Kivenlahti metro station, and work on the technical building services has also begun. The accident will not affect the construction work. Excavation of the pipeline trenches continues today, in line with the original plan.

Further information:

Länsimetro’s feedback line (Mon–Fri, 9 am to 3 pm): +358 (0) 50 377 3700

Loud sawing work in Matinkylä metro’s service tunnel from 17–19 July 2019

Diamond sawing work will be carried out in the Matinkylä service tunnel from 17–19 July 2019. The work is connected to the construction of the Tynnyripuisto area.

The work will take place between 7.00 am and 4.00 pm. The noise caused by the diamond sawing may carry all the way to the metro platform.

We apologise for any inconvenience caused by the construction work.

Further information:

Mikko Raisio, Site Manager, YIT: +358 (0)50 3305503, mikko.raisio(at)yit.fi
Länsimetro’s feedback line (Mon–Fri, 9 am to 3 pm): +358 (0)50 377 3700

Technical construction work supervisor works in the office and the tunnel

Sami Toivola, Bachelor of Construction Management, has started as supervisor of technical construction work at the West Metro’s Kivenlahti station. The supervisor’s work includes, for instance, inspecting reinforcements and various installations, as well as supervising and signing off on work samples. Toivola also takes part in various meetings related to the contract’s procurements, construction, scheduling and costs, to name a few.

“In addition to working in the office, I visit the work site every day,” says Toivola, who has worked at Kivenlahti for a month now.

Toivola has extensive experience in the construction industry, most recently having worked for AKR Betoni Oy. He has also worked at SRV, Lemminkäinen and Consti Julkisivu Oy. His background covers residential and industrial construction, as well as renovations.

“When the opportunity to join the metro construction project came up, I was definitely interested, because this is a major and long-term project. I also happen to live right near phase two of the metro project, which is currently under construction,” he says.

Structural work on the station is under way right now in the Kivenlahti contract, and it includes a great deal of concrete construction. Toivola holds a qualification in exceptionally demanding concrete construction from Suomen Betoniyhdistys ry (Concrete Association of Finland), something that is necessary when it comes to supervising the metro’s structural construction work. In addition, work on the technical building services has already been started in the metro station’s basement level.

“The electricity and HVAC contracts have their own supervisors, but naturally we work together a lot,” says Toivola.

Saturday work at Kivenlahti during summer; all-day concrete casting to take place on 17 July

From July until the end of September, work on Länsimetro’s Kivenlahti construction contract will also take place on Saturdays between 9.00 am and 6.00 pm. Construction work will take place in both the underground tunnel and aboveground, at both entrances, on Saturdays. From Monday to Friday, the construction work will be limited to between 7.00 am and 6.00 pm.

Work will be performed on Saturdays in order to efficiently pace the work stages. On Saturdays, only non-noisy work stages – such as reinforcement work, formwork and joint sealing – will be carried out. Drilling and excavation work will not be performed on weekends.

In addition, on Wednesday, 17 July, a large wall be cast at the Kivenlahdentori entrance, and the work will end at 10.00 pm. Unfortunately, the work cannot be interrupted earlier, due to the size of the structure to be cast. The casting work will not cause considerable noise to the surrounding environment.

Further information:

On-call phone line, Skanska Infra Oy: +358 (0)50 402 3044
Länsimetro’s feedback line (Mon–Fri, 9 am to 3 pm): +358 (0)50 377 3700

Trench excavation during week of 22 July for the Kivenlahti metro station construction project

Trench excavation will begin during the week of 22 July at Seitsenmerenreitti as part of Länsimetro’s Kivenlahti construction project. The excavation work will last a total of one week.

The reason for the trench excavation is because of the planned construction of water and sewer lines on Seitsenmerenreitti. They are related to both the Kivenlahti metro station’s water and sewer connections and to the public utility lines that are to be constructed for the City of Espoo. Fire water and household water pipelines and rainwater and wastewater sewer pipelines and their wells will be constructed for the city. In addition, a new district heating pipeline will be built.

The work will take place on Seitsenmerenreitti, in the immediate vicinity of the Kivenlahdentori entrance, on the aboveground sections of the work site. The  excavation will take place during the week between 7 am–6 pm.

Work on water and sewer connections and district heating for the Kivenlahti metro station and public utility work for the City of Espoo will be completed by the end of October.

We apologise for any inconvenience that the work may cause.

Further information:

On-call phone line, Skanska Infra Oy: +358 (0)50 402 3044
Länsimetro’s feedback line (Mon–Fri, 9 am to 3 pm): +358 (0)50 377 3700

Pioneering in Building Information Modelling – XR pilot project on the metro’s smoke venting system finished in the spring

Länsimetro wants to be a pioneer in Building Information Modelling. At the moment, West Metro’s project planning team is looking into the possibilities offered by extended reality (XR) tools. These would complement the VR technology, which is already widely used in the industry, and creates a 3D view of, for instance, a planned metro station before actual construction work begins.

”Extended reality technology adds, as the name suggests, new elements to an existing planning environment. On the West Metro planning team, we have carried out a project to display a section of the metro’s smoke vent system as a small-scale model in a virtual smoke exhaust control room, which is almost identical with the real control room now under construction. In the pilot, we are using a headset technology that allows a higher resolution than normally used in virtual reality. The users of the model can see what happens if they activate the smoke vent system and how it works in a real situation,” says Jarkko Aittoniemi, Design Manager for the West Metro project.

The purpose of the XR pilot for the smoke vent system was to illustrate how XR technology works – during the summer, the intention is to examine how this technology could be used more extensively in the project. Decisions on what ideas will be implemented will be made in the autumn.

The intention is to use XR technology mainly for training purposes during the West Metro project. It enables the viewing of the finished metro with its technical systems in an illustrative format before the actual infrastructure is ready.

”In this way, we could start training for the commissioning phase before the infrastructure is finished and gain benefits in terms of schedule and costs,” Aittoniemi says.

”Metro is a complicated and wide-ranging infrastructure site. The smoke vent system, which was selected as the pilot area, includes several controllable functions, and the smoke extraction area is considerable. The XR model helps us gain an understanding of the complex system despite the limitations of the physical environment,” says fire safety expert Mikko Mauro from the West Metro project.

Both Aittoniemi and Mauro believe that XR technology will be used more extensively in construction projects in the future. Even now, various parties, such as the European Space Agency, employ this technology in their projects. Länsimetro has been developing the pilot model together with Teatime Research.

”Our pilot has drawn international interest, and people from Copenhagen’s metro project, for example, have been in contact with me,” says Aittoniemi.

Concrete casting and element deliveries to begin in the Kaitaa metro station contract

Element installation and concrete casting will begin in the West Metro Kaitaa construction project during the week of 1 July. Work will be carried out at the future metro station’s Kaitaantie entrance (Kaitaantie 6) and at the provisional Iivisniemenkallio entrance (Hannuskallio 5) in the aboveground areas of the worksites.

The metro station’s load-bearing structures will be cast in concrete, and part of the concrete will be transported to the site as finished elements, and part as ready-mix concrete to be cast on site. The concrete work phase will increase worksite traffic – the concrete trucks will mainly take the Kaitaantie and Hannuskallio route.

Noisy work will be carried out during normal working hours from Monday to Friday between 7 am and 6 pm. Quiet work can also be carried out outside those hours. The transportation of concrete elements and concrete casting are estimated to last two months, starting during the week of 1 July.

Further information:

Ari Larikka, occupational safety manager, YIT Rakennus Oy: tel. +358 (0)50 440 3011, ari.larikka(at)yit.fi
Länsimetro’s feedback line (Mon–Fri, 9 am to 3 pm): +358 (0)50 377 3700

The journey of concrete

The main building material of West metro’s stations and railway lines is concrete. Its journey to West metro’s walls, floors, elevator shafts and platforms starts in a mixer.

The concrete truck’s mixer is slowly filling up. From Ruskon betoni’s Kivenlahti factory, concrete is transported to Finnoo metro station for use in constructing vaulted ceilings and floors.

Before that, a cement truck arrives from Finnsementti’s plant in Pargas. In a large concrete mixer, the cement is mixed with aggregate and water, and synthetic and steel fibres are added as needed to prevent cracking.

The concrete factory’s large machines do not have operators. The controls are in an office, which has digital screens for monitoring the processes.

– It may come as a surprise that this work is done indoors and it is not messy. Everything starts with receiving an order. In the West metro project, preliminary information is sent to us the previous week, and the orders are confirmed two days before delivery, says Regional Manager Jukka Tuohino.

The concrete pour rate is agreed in advance. For West metro work sites, concrete trucks often make deliveries every 20 minutes. The digital screens show two mixers preparing concrete. Getting the relative proportion of the aggregate right at the factory is important as it affects the strength of the concrete. For example, elasticity or porousness can be increased with the right materials.

In addition to the office and concrete plants, the factory has a laboratory, where cubes of concrete are ready for the compressive strength test. The laboratory also measures air content and depressions and
monitors fibre content in concrete.

In addition to quality control at the factory, quality is tested at the work site, and Ruskon betoni’s test results are reviewed by an independent third party.

Originally published in West Metro magazine 1/2019. 

Photo: Timo Kauppila, INDAV