First Atlas Copco WL4C30 Drill Rig at Work in FinlandThe Vuosaari harbour rail line in Helsinki is a new 19 km-long single-track freight infrastructure to handle ten trains a day in each direction. It includes two tunnels, the 600 m Labbacka tunnel built by Skanska Tekra, and the 15,540 m Savio tunnel. The latter has been divided into five contracts (TU 2 to TU 6) awarded in December 2004 to three Finnish contractors. YIT is excavating in Långmobergen (contract TU 2) and Jokivarsi (TU 5). Lemcon Infra has started excavation in Kaskela (contract TU 3) and Savio (TU 6). Kalliorakennus has started work in Kuninkaanmäki (contract TU 4). The Savio railway tunnel features a 65 sq m section, 7.5 m wide x 9 m high. Contracts TU 2, TU 3, TU 4 and TU 5 include also four access and work tunnels, which lengths vary from 200 to 400 m (Långmobergen, Kaskela, Kuninkaanmäki and Jokivarsi). There are also four vertical shafts (Hakunila, Kuninkaanmäki, Myras and Leppäkorpi) along the tunnel alignment. The geology is typical Finnish hard granite and gneiss. There are some weakness zones in contracts TU 2 and TU 5. The optional 1.3 km in contract TU 4b includes the difficult Myras weakness zone.Contracts TU 2 and TU 5 are being excavated by YIT, at respective depths of 25 m and 35 m from the Långmobergen and Jokivarsi access adits excavated to the middle of each contract alignment so that two faces could be opened. Contract TU 2 includes 2,152 m of main tunnel and the Hakunila vertical shaft. Contract TU 5 includes 3,572 m of tunnel as well as the Myras and Leppäkorpi vertical shafts. YIT has one Atlas Copco WL4C30 four-boom drill rig which is used on contract TU 5 and one Atlas Copco XL3 C three-boom drill rig which is used on contract TU 2. Atlas Copco's WL4C30 drill rig has been working very well. At the worksite, the underground drill rig equipped with super-fast COP 3038 hammers can drill a 65 sq m tunnel face (125 holes) 40% faster than the XL3C drill rig fitted with COP 1838HF hammers. The WL4C30 is the latest and most powerful in Atlas Copco's range of underground tunnelling rigs. The fully computerised drill rig is a leap forward in terms of productivity and cost savings. It has close to twice the drilling capacity of the three-boom WL3 C rig using COP 1838ME hammers, thanks to a 50% higher net penetration rate achieved by the COP 3038 hammers. Despite the increased speed, the stress level in the drill steel remains almost the same, maintaining long drill steel life and low cost production. The WL4C30 rig is easy to operate since a unique operator can supervise all the four booms simultaneously. Visit www.atlascopco.com and www.boomer-rig.comIn good Finnish granite it is normally possible to do all the rock support tasks (bolting and shotcreting) afterwards. In weakness zones, rock support works must be done before blasting the next round. Rock bolting is done usually with normal cement grouted ribbed steel bars, diameter 25 mm. The length of rock bolts varies usually from 3 to 5 m. If rock bolting is needed before blasting the next round, CT-bolts (length 3-5 m) of Orsta Staalindustri are used. The thickness of shotcrete layers (with steel fibres) varies usually from 50 to 100 mm. YIT is utilising a Cat 980F for loading in TU 2 and a Cat 980G in TU 5. Loading machines are equipped with side tipping buckets. Normal trucks (4 or 5 axles) are used for muck hauling. The breakthrough is expected in the summer or autumn of 2006, depending on rock quality. Progress to date has reached 700 m on contract TU 2 and 600 m on contract TU 5. Visit www.yit.fi, www.ct-bolt.com and www.cat.comContract TU 4, built by Kalliorakennus, is driven at a depth of 60 m from the 20 m x 20 m x 10 m Kuninkaanmäki access adit and includes 2,080 m of tunnel section (TU 4a and 1.3 km optional in TU 4b). Kalliorakennus is using a Tamrock Axera T11 three-boom jumbo and a Tamrock T316 Super Para three-boom jumbo. Most of the explosives are provided by Forcit. Types of explosives are Kemix A, Aniitti and pipecharges. Approximately 450 m has been excavated to date with 5 or 4 m drives. Bad rock allows only 3 m drives. The geology is solid Finnish granite with some fractures. The rock had been solid and only a few CT-bolts have been installed. Steel arches and concrete formwork are needed only in Myras weakness zone (option contract TU 4), where the length of the concrete structure will be approximately 200 m. A Cat 980G loader and various dump trucks (Volvo, MB and Scania) are used. Visit www.kalliorakennus.com, www.tamrock.com and www.forcit.fiContract TU 3 is tunnelled from two drives by Lemcon Infra, part of the Lemminkainen Group, at a depth of 60 m from the 325 m Kaskela access adit and includes 4,111 m of main tunnel and the 4.3 m x 6.9 m x 65 m-deep ventilation Kuninkaanmäki shaft. The bottom of the shaft lies 12 m below the sea level and surface level is +53 m. The excavated section of the tunnel in contract TU 3 is 58 sq m. Contract TU 6 includes 1,625 m of main tunnel and has only one working face (no access tunnel and no shaft) opened from Savio at the north end of the tunnel. The first 370 m of tunnel in contract TU 6 has a cross section of 70 sq m and the rest of the tunnel has an area of 60 sq m. The TU 6 tunnel is blasted using 'Irene', a Tamrock Axera T11 Data jumbo with three booms. The TU 3 tunnel is drilled and blasted using 'Marja', a Tamrock Axera T12 Data 415 jumbo, which has four booms and 'Riitta', a Tamrock Maximatic 205-121 with two booms. The supplier of explosives is Forcit. Each blast consists of various types of explosives: Fordyn-dynamite is used as base charge; F-pipecharges are used for blasting contour lines, when the rock surface has to be as whole as possible; Aniitti is used as a column charge; Kemix A is an emulsion explosive, which is used in bottom as well as column charges; and Nobel Prime is used as initial charge for ignition of Kemiitti. There are two drives at TU 3. To date, 120 m has been excavated on the drive towards north and 100 m at the drive to south. Progress at TU 6 is approximately 315 m. The geology of the area makes the project very challenging. The bedrock is soft and broken in many places, which requires the unforeseen preliminary injection of cement, bolting and shotcreting. The tunnel is supported by galvanised iron bolts of different diameters and lengths. Bolting is planned to be installed systematically. When bolting is needed for safety reasons, 3 m-long CT-bolts are used. Shotcrete will be sprayed with the first layers reinforced with steel fibres and the surface layer without fibres. A mucking-out subcontractor is operating two Cat wheel loaders (980G and 980C). The blasted rock is transported to the port of Vuosaari by 5-axle trucks (Volvo, Sisu and Scania). The TU 3 contract also includes a cavern at the end of the access tunnel. This 16 m-wide 24 m-long 5 m-high cavern is a technical facility for pumping the drainage waters. Thirteen measuring dams will be also excavated. The breakthrough will be achieved in both contracts during week 41 in 2006. Visit www.lemcon.fiBuilding the Savio railway tunnel involves excavating about a million cubic metres of rock. This will be transported to Vuosaari and used to fill harbour structures. The environmental impact of tunnelling is closely monitored. Before excavation began, studies were carried out and structural solutions were devised so that the project will not harm buildings, wells or nature. Throughout the full duration of the project, residential areas and groundwater levels will be monitored and noise and vibration will be measured as necessary. The total cost is about EUR100 million (EUR65 million for excavation, EUR25 million for superstructures and EUR10 million for operating systems). Click fi/18. Visit www.vuosaarensatama.fi/en/index.html 28/05. Atlas Copco's WL4C30 four-boom drill rig at the Savio rail tunnel near Helsinki. Sandvik Tamrock's Axera T11 three-boom tunnelling jumbo at contract TU 4 of the Savio rail tunnel. ‘Irene’, Lemcon’s Tamrock Axera T11 underground drill rig on contract TU 3.