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by Nick Drew  |  Wed 22 Jan 2020

€275 million Lahti ring road landscape transformed with help from Allu

A series of 167 improvements are currently underway around the southern ring road of the Finnish city of Lahti. One of the main contractors for the project, Skanska, has added a new tool to its armoury in making the work as efficient, cost effective and environmentally friendly as possible. Allu DN Series Transformers have been successfully put to work screening excavated materials for reuse on the project thereby boosting the environmental credentials and efficiency of the project.

€275 million Lahti ring road landscape transformed with help from Allu

The southern ring road around the Finnish city of Lahti (Finnish national road 12) will when complete boost to the area’s economy with the project acting as a driver for industrial growth through improvements to the general traffic flow. At the same time, the ring road project is seen as of great strategic importance to the entire traffic system of Finland as it substantially improves cross country connections and links to St. Petersburg in Russia that are vital to Finnish industry.

“The road project will unambiguously bring growth and well-being to Lahti: jobs, apartments and better opportunities for entrepreneurs. Lahti's competitiveness will improve significantly and the operating conditions of the basic industry will be strengthened under the influence of Finnish national road 12. We are very happy and thankful for this decision,” says City Board President Juha Rostedt of the project.  “Building the ring road to the south side of Lahti is a significant investment in the development of Lahti. We are ready to begin the project and will utilise the ring road to the fullest for the environment, the business sector and the job market,” added Lahti’s mayor Jyrki Myllyvirta.

Background to the development

The Lahti Southern Ring Road project involves rerouting the main road No 12 to the south of Lahti and improving the regional road No 167, which enters Lahti from the south. Main road No 12 is a major national east–west route, with the road currently running through the centre of Lahti and the built up areas of Hollola.

The development and infrastructure project consists of two works sites and three separate contracts. Subproject 1A involves widening the Lahti Southern Ring Road at the Hollola end to provide two lanes along main road No 12 between Soramäki and Okeroinen, as well as building 17 bridges. Subproject 1B covers the southern end of the Lahti Southern Ring Road, with work starting to the east of the Okeroinen interchange and ends at the Joutjärvi interchange. This is a technically challenging stretch of the road, and the project involves, among other works, building several interchanges as well as two tunnels.

Subproject 2 involves widening Uudenmaankatu to provide four lanes along regional road No 167, which enters Lahti from the south, between Renkomäki and Laune. The project also involves renovating underpasses and bridges. Works along regional road No 167 began in the spring of 2017 and works along main road No 12 in the spring of 2018. The goal is to reopen main road No 12 to traffic towards the end of 2020, with work finishing in 2021, and final surfacing is scheduled for 2023.

Objectives of the project

The rerouting of No 12 main road further south will improve traffic safety and flow considerably, as it will divert traffic away from the centres of Lahti and Hollola. Quality of life will improve in residential areas once traffic is diverted, and lower traffic volumes will mean lower noise levels, emission levels and congestion in the surroundings of the current route of main road. In addition, safer and smoother traffic flow will also improve the reliability of goods transport to the increasingly important Lahti business hub.

From the perspective of land use development, the Lahti Southern Ring Road will provide new opportunities for developing the area around Lahti railway station, the former plot of the Asko furniture factory, the Sopenkorpi district and the centre of Hollola. The bypass will promote the development of the Nostava logistics park and create efficient transport links to the Kujala and Lotila industrial parks. The rerouting of the main road No 12 further south will also reduce the risk of groundwater contamination in the Salpausselkä area, which is an extremely important source of groundwater.

Ground works and landscaping

Given that the project has impressive environmental credentials that will not only improve the infrastructure, but will also lead to a higher quality of life for residents, the way excavated materials are treated has been an important concern on all the subprojects.  One of the main contractors, Skanska Infra Oy, has been using Allu DN Series Transformers for landscape purposes, helping to create noise reducing embankments and to mix soil for planting.  The Allu Transformer has proved perfect for the tasks at hand dealing with soils and other excavated material, being highly mobile enabling it to go directly to where it is needed. This has meant that there has been no need for transporting material to and from site thus further lowering emissions and reducing costs.

As part of its work on the ring road project, Skanska Infra Oy, is responsible for landscaping and constructing road slopes, embankments and noise barriers. To this end the Allu DN 3-17 X75 has proved to be invaluable. This is a screening attachment for compact base machines, being suited for excavators up to 28t, loaders-tractors and backhoe loaders up to 14t. The entire DN series is ideal for large landscaping projects, as it offers a truly mobile solution, providing high levels of working versatility and flexibility even in the most challenging environments.

The Allu Transformer comprises of an attachment which screens, crushes, aerates, blends, mixes, separates, feeds and loads materials. This results in the feed material being effectively transformed into highly valuable products, making operations on the project more efficient, and more profitable.  At the heart of the Transformer is the unique top screen of its bucket. This is where the screening blades spin between the top screen combs with the end material size being defined by the space between the combs. Effectively these screening combs carry most of the material weight to ensure the drums and bearings take on less impact and load. This construction is clog free and maintains good capacity even with wet materials.

The use of the Allu Transformer has been pivotal on the ground works and landscaping operation on the southern ring road project. Following excavation the material is collected and its usability is analysed, then screened and mixed using the Transformer to provide a smooth soil mixture. After that, the ready to use soil is spread where it is required, ready for any planting.  In the latter case, the construction of sight and noise barriers, as well as reaffirming the environmental credentials of the project, sees reforestation as a key part of the project. This all means that the use of the Allu Transformers sees material being reused from excavation operations, with no requirement to buy or transport extra material from outside the project, which is inefficient, both economically and environmentally.

Checkout our video of an Allu screening bucket being demonstrated at the Maxpo show in Finland last year. 

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