The city of Tampere is extending its tram routes to the western suburbs. Infrastructure construction and maintenance in this alliance project are provided by YIT. They have used a variety of foundation engineering methods to ensure solid results.

Tramway Section 1 (TAS 1) was implemented in six segments from 2017 to 2021. The first section included tram tracks and stops from Pyynikintori eastwards to Hervantajärvi and from the University Hospital to Sori Square. Service on the first section began in August 2023.

Tramway Section 2 (TAS 2) includes the section from Pyynikintori to Lentävänniemi in the west. Construction of the last part, Santalahti–Lentävänniemi, began in spring 2022. If all goes to plan, tram service to Lentävänniemi could begin at the start of 2025.

The total length of the Tampere tram network for sections 1 and 2 is approximately 24 kilometers. The planning phase for tramway section 3 is currently underway, with the city council expected to decide on its implementation by the end of 2024.

A wide variety of tasks
YIT’s role in the project has included foundation work, sewerage, cabling, bridges, retaining walls, rail installations, paving, roundabouts, sidewalks, 24 tram stops, and more. Due to the significant elevation differences along the route, 20 retaining walls were constructed. Nine new bridges were also built, including a 18-meter-high railway bridge, and the 250-meter Vacker Bridge.

YIT also constructed a modularly designed depot in Hervanta. Before its construction, 250,000 m3 of rock was excavated, some of which were used for the depot’s site embankments. The remaining quarried rock was used as aggregate elsewhere in the project.

Foundation work is key
The foundation work included varying types of ground reinforcement as well as the lower structure of the tram tracks.“We’ve made reinforcements for all sorts of foundations: clay, hard rock, several meters of peat, etc. We’ve done multiple kilometers of piling, especially for bridges, where we used piled slabs. Also, various retaining walls, mass replacements, lightweight fills, and preload embankments,” says Veetu Helkiö from YIT Infra, who worked as a supervisor for TAS 1 and a site engineer for TAS 2.

YIT has mainly used their own equipment in the foundation work. “We’ve used both drilled and driven piles extensively for reinforcements, with Robit supplying reamers for the piles and bits for drilling. Most reamers went directly to the pile supplier, which sped up the process. Some were also welded on-site. We had a good supply of drill bits the whole time, and Robit’s deliveries were timely, despite the global challenges with material flows. Domestic production is an asset, as was the short distance from Robit’s Lempäälä facilities to the tram construction site, which means deliveries were really quick from Robit’s warehouse,” Helkiö praises.

The foundation work for TAS 2 was completed late last year. “The project went well overall, and we met our schedules despite challenging times. This was a unique and interesting project, integrating many different work phases,” says Helkiö.

Robit DTH SR pilots and ring bits were widely used by YIT in the foundation works on the tramway project.

Replacing and repairing bridges improves mobility and can increase quality of life in communities. In the Northeast U.S.A., M.A. Bongiovanni, a General Contractor out of Syracuse, NY, is helping to maintain our beautiful roads by providing the foundation for safe, resilient and reliable infrastructure.

M.A. Bongiovanni specializes in the Water/Wastewater industry and in geotechnical work, including driven and sheet piles, retaining walls, piers and drilled shafts. When they were chosen to replace a bridge on New York State Route 8, they turned to OCI Division of Global Drilling Suppliers for drill tooling. As often occurs in geotechnical drilling, ground conditions require special accommodations. This job was no exception with piles needing to be placed in overburden consisting of cobbles and boulders. Drilling of overburden without casings could result in collapsed holes and tool loss.

Of Course, drilling in these environments calls for the right equipment. The job required the installation of 22 centerline soldier piles, 24” diameter, through 33’ of overburden and 7’ of rock as well as 11 wingwall soldier piles through 30’ of overburden and 9’ of rock. The Robit® Steel Fist wing bit system was the clear choice.

OCI Division of Global Drilling Suppliers is a manufacture of drill tools, drilling accessories, and design-built drilling equipment. As a distributor of Robit products, they assisted M.A. Bongiovanni with their first Steel Fist concentric overburden drilling system. The drilling process utilized the Robit® DTH SF (Steel Fist) and Robit® Hyper 181 18” hammer with a single rotary head duplex drilling operation. Robit was able to manufacture and deliver the Steel Fist pilot through OCI within the job’s 6 week window before drilling started. Drill tools utilized by M.A. Bongiovanni, manufactured by OCI Division of Global Drilling Suppliers were:

• Dual Swivel having high-pressure air inlet and discharge to enable drilled spoils containment includes a J-slot driver for driving 24” OD casing.
• Canister style drill rods, 20” OD
• Vibration dampening equipment
• Over the hammer stabilizer, 20” OD
• Inline oil injection equipment
• Inline water injection equipment

OCI Division’s onsite field consultant was present while tooling up and during initial drilling, and is pleased to report all expectations were met and exceeded with the Steel Fist’s performance. The solid construction of the wings held up very good with no carbide loss or trouble with opening or closing during loading or unloading of casing material
Speed to finish a project is very important when replacing a bridge, as the structure being repaired typically restricts traffic during the work. Using the Robit® Hyper 181 down-the-hole hammer with the Robit® DTH SF XL2 for use with 24” OD x.500 wall casing material all holes were successfully drilled on schedule and under budget.

The Pasila area holds a major role in the vision for a future Helsinki: there are plans for it to be the new heart of Helsinki. One of the key words for the plan is ‘Tripla’. Upon completion, the billion-euro construction project, massive on Finland’s scale, will connect East and West Pasila. Offices, flats, a shopping centre, a public transportation hub, hotels and other services will emerge within a three-block area. Tripla’s developer is YIT.

Completing Tripla will naturally require comprehensive foundation engineering work. The lowest level of the block will be a parking facility on which the foundation work was begun in April 2015. It was decided that the surrounding retaining wall would be implemented as an RD-pile wall because it can tolerate loads, allows relatively rapid installation and has accurate dimensions even in challenging soil conditions. The difficulty is ensuring the watertightness of the RD-pile wall and significant amounts of slurry can accumulate during the drilling phase.

Strict demands, challenging conditions

It was known from the very beginning that the project was going to be challenging. Developers were faced with backfill full of boulders, combined with construction waste. Much of the backfill was saturated with badly polluted liquids. The nearby busy railway yard posed restrictions of its own.

The quality criteria were also strict. The design age of the structures, including factors such as corrosion resistance and watertightness, were specified to be 200 years instead of the more usual 100 years. The location and incline demands on the RD-pile wall were also relatively strict.

A three-company consortium was responsible for the construction of the retaining wall on behalf of the main contractor YIT. The main contract for the piling was carried out by Keski-Suomen Betonirakenne, the drilling by the Estonian subcontractor Fort Ehitus, with Ilmi Solutions functioning as the consultant. Robit supplied the drill bits for all of the drilling. YIT also uses Robit’s Top Hammer equipment at the worksite.

Inside the bedrock in three phases

There were three main phases in building the retaining wall. During the first phase, the piles were vibrated through the loose clay and sandy soil into the hard ground moraine. During the second phase, the vertically installed piles were emptied with an auger, from the clay layer all the way to the tip of the pile. In the third phase, the piles were drilled through hard or extremely hard moraine into the bedrock to a maximum depth of 1.5 m. Robit’s opening winged bit was selected for down-the-hole drilling. Senior Specialist Kari Juntunen was onsite to supervise on behalf of Robit.

“The alternative for the winged bit would have been a traditional ring bit. The subcontractor took a bit of a risk when selecting the winged bit because there were some tricky spots in the bedrock. We at Robit were still making further improvements to the bit during the project based on tips given to us by the subcontractor. Everything turned out all right in the end and the costs for the customer were lower than they would have been with a ring bit,” says Juntunen.

Trust and seamless collaboration

“The job was completed on schedule with excellent results. I have to take off my hat to the Fort Ehitus guys. We had a strong trust in them to begin with: I had worked with them before on a piling project and became impressed by their expertise,” says Juntunen. According to Jouko Pasanen from Ilmi Solutions, which oversaw the worksite, the co-operation was seamless.

“Despite the challenging worksite we barely ran into any problems. Once my phone rang at nine in the evening. A subcontractor told me that a bit had broken, what should they do? We had agreed that there should always be spare bits available. I promised to be there at six the next morning with a new bit. And I was. The subcontractor thanked me and said that no other supplier could have done it,” says Juntunen with satisfaction.

The retaining wall was completed on time before the new year. The work at Tripla is still far from finished, however. The first cars will not be able to park in the garage set off by the retaining wall until 2019.

Drilling of Tripla’s retaining wall
• RD700 pile elements
• D711 x 14.2 RM/RF interlocked piles, 746 pcs
• Robit DTH SF 711/16 winged pilot bit
• Length of piles 5.5–33.5 m
• Altogether 16,335 m of piles
• Drill rig with a 40-m mast

U.S. Route 53 traverses the state of Minnesota, from Duluth at the southwest end of Lake Superior, ending 240 km later at the Canadian border. On its way it crosses the socalled Iron Range, an area rich in iron ore, which has served the raw material needs of the American steel industry since the 19th century.

Today, the ore deposits in the Iron Range are far from depleted. On the contrary, just south of the city of Virginia, a mining company is in the process of expanding an old mine pit. As it happens, Route 53 currently runs right on top of the planned expansion and needs to be relocated. The main element of the relocation project is a new bridge across the neighbouring Rouchleau Mine Pit.

Minnesota’s highest bridge

Abandoned in 1977, the Rouchleau Pit has since served as a tourist attraction. The new bridge will be 335 metres (1,100 ft) long with an elevation of 61 metres (200 ft), making it the highest bridge in elevation in Minnesota.

The construction of the foundations of the bridge started in December 2015 with the installation of 30-inch piles. Drilling deep piles into very hard ground with a high iron content is quite a challenge. Due to strength requirements the holes need to be drilled 12 metres into hard rock – way deeper than at a typical bridge construction site.

Veit USA took the challenge of the drilling work. For the casing advancing system, Veit considered two suppliers.

Tight time schedule

– Veit had heard about Robit through the industry grapevine. They contacted us and presented their two challenges: deep piles in a mine site and a very tight delivery time, says David Delorme, General Manager of Robit Inc.

– We were selected because we were able to supply on a very short notice. We designed a system for the conditions Veit described, and delivered in six weeks – exactly as promised. What about the drilling work itself – how has it been coming along?

– This is the biggest piling job for Robit Inc so far. Despite the technical challenges posed by the rock and the length of the piles, we haven’t faced any major problems, and we are well within schedule, David says.

The installation of the 30-inch piles is set to be completed by mid-March, 2016. Work on the site continues at a swift pace though. The new bridge spanning the Rouchleau Pit should be open to traffic in late 2017 – offering a magnificent new lookout spot for travellers on Route 53.

Bridge construction for Route 53 relocation, Virginia, Minnesota
• 5 x 762 mm (30”) QL200s pilot bit
• 35 x 762/12,7 (30”) mm DTH RoX+ HD (Heavy Duty) ring bit
• Bermingham Reverse Circulation (RC) drill tube system
• Bermingham 50 m lead
• 4 x 25 bar compressor + oiler
• Drill hole depth: 53 m, into hard rock 12 m

Edvard Munch was an incredibly prolific artist. He willed 28,000 of his works – paintings, sculptures, and photographs – to the city of Oslo. It had long been clear that the old Munch Museum was too small to house the collection. A new one is now being built on water in Bjørvika bay in downtown Oslo.

There was a long and heated debate about where the new Munch museum should be built and what it should look like. In 2008 the city of Oslo announced an architectural competition, and the following year a proposal called Lambda, by the Spanish architect Juan Herreros, was declared the winner.

Initial controversy

As is often the case with contemporary architecture, Lambda’s bold design and size met with some resistance. It was considered strange shaped and too tall for its surroundings. After years of a political tug-ofwar, the construction work finally started in 2016.

The job site was not the easiest possible either: Lambda was designed to rise directly from the sea. That meant a massive piling project for the contractor Hallingdal Bergboring. Robit, having been in close cooperation with Hallingdal for years, was selected as the provider of drilling tools for the project.

Custom-made drill bits

Old seaports are often challenging for piling jobs. The bottom of Bjørvika was filled with silt, large boulders, wooden piles from old dock, et cetera. The bedrock underneath them, on the other hand, was very hard. For these reasons Robit and Hallingdal designed the optimal drill bits in cooperation.

Location in the city centre was another challenge. The famous Oslo Opera House sits right next to the job site; one had to make sure that its foundations remained unharmed while drilling up to 12 metres into the bedrock. This was achieved by using Robit’s DTH-RoX+ FC (Flow Control) pilot bits.

16 kilometres of piles

For the foundations of the Munch Museum, some 16 kilometres of piles were drilled, 311 piles altogether, the thickest being 711 mm in diameter. Some were drilled on solid ground; others from a drilling platform floating on the bay. In these circumstances, drilling work takes a lot of skill.

– When you’re on the platform, controlling a machine that’s thumping on the rock 50 metres below you, you need to keep your eyes, ears, and touch on full alert, says Hallingdal’s operations manager Sverre Bjella.

Despite the difficult conditions, no major surprises or problems were encountered. The piling project was finished on time in October 2016. In addition to Hallingdal, Robit’s Senior Specialist Kari Juntunen extends his thanks to other parties involved.

– Our agent Norsk Pumpeservice was responsible for the storing and technical service of the drilling equipment, and did a great job. There wasn’t a single gap in the supply of consumables on the job site, Kari says with content.

In October 2016, Princess Mette-Marit laid the ceremonial foundation stone for Lambda. The imposing, glass-faced 12-story building is set to open its doors to the public in 2020.