Bridge building requires a strong foundation and an experienced pool of piling companies and equipment providers. An extensive reconstruction work of the Kallansillat bridges took place north of the city of Kuopio, Finland and provided an opportunity for Junttan and its partners to show their skills and capabilities in such demanding conditions. In the project, approximately five kilometres of Highway 5 was transformed into a motorway. A total of 26 bridges were repaired or constructed, along with building a 7-kilometre-long service road, 1.5-kilometre-long new railroads, and three interchanges.
The fact that the work was performed over water made the job even more challenging – for both the workers and the equipment. The depth of the water at the installation site is approximately 10 metres, and the work is performed from a temporary bridge founded on steel piles. The bearing stratum for the piles was the rock. The target depth of the piles can be found in the Finnish bedrock underneath the varying layers of mud, sand, clay, and moraine.
The project consisted of one particularly unique construction challenge, The Tikkalansaari island railroad bridge. The railroad had to be hoisted hydraulically when necessary, making the headroom for the waterway 12.5 metres. This introduced a great opportunity for Junttan and its partner companies to gain hands-on understanding of bridge building in demanding conditions.
Both pile driving and pile drilling were used in the foundations of the bridge. The Junttan HHK4SL hydraulic hammer that is used for the pile driving is equipped with a three-ton extension for the PDA measurements in order to achieve the energy required for the measurements with the existing equipment. If necessary, the rig used in the pile driving operations can be equipped with a special Junttan gear to accomplish the final blows. In this case, the mass of the free falling, hydraulically released load is 10,000 kg. The piles processed with the Junttan PM23 were 16 metres long at most. The pile extensions were made by welding, and the welds were inspected with ultrasonic testing.
The pile-driving foundations for the Tikkalansaari railroad line were made by Kantolan Paalutus Oy. The company used the Junttan PM23 pile driving rig equipped with the Junttan HHK4SL hydraulic hammer, acquired in 2001, for the piling work. All in all, Kantolan Paalutus Oy had six Junttan pile driving rigs, of which two are of the PM23 type. The PM23 rig that was used at Tikkalansaari has already worked for 10,000 hours without the need for any extraordinary maintenance operations. “The perfect tool for the job,” says driver Harri Inget. He justifies his statement with the good reach, excellent batter piling characteristics, and the precise pile control of the Junttan PM23, required e.g. when making pile extensions. Combined with an efficient and reliable hydraulic hammer, these characteristics guarantee that the work runs smoothly and swiftly.
The project was finished on schedule by 2014 and cost €90 million in total. The value of the main contract was approximately €73 million. The contract directly employed some 500 people, of whom at most 150 worked on the site at a time. The total amount of structural piles in the entire project is approximately 3.2 kilometres.
Interested in more details? Please contact:
Junttan Oy, Area sales manager Kari Pöllänen, firstname.lastname@example.org