The end of works at the DK 86/81 junction is approaching
The construction of one of the most important road junctions in Poland is entering a decisive phase. Already 75 % of all the work has been done! The investment includes new, expanded sections of the National Road No. 86 and the National Road No. 81, as well as six new flyovers, two underground pedestrian crossings and nine grade-separated slip roads. The fifth of the slip roads will be put into use in November.
“We knew from the very beginning that the implementation of this investment would be a huge engineering and logistical challenge. It is estimated that up to 60,000 cars pass through this area daily. Additionally, there is a railway in the area of works. All this makes the implementation of the investment while maintaining the passage through the reconstructed junction a huge challenge for the contractor, but also for the drivers,” says the Mayor of Katowice, Marcin Krupa. “I am convinced that the completion of the investment will allow to unblock another “bottleneck” in the city’s communication system, but most of all, thanks to grade-separated junctions, it will significantly improve the safety of road users,” adds the Mayor.
In addition to the new road system, the scope of works includes the necessary reconstruction of all underground utilities networks. So far, the general contractor, i.e. NDI based in Sopot, has already reconstructed gas networks with a total length of 2.7 kilometres, as well as water supply, heating networks and a high-voltage line on the section clashing with the investment, over one kilometre long. Additionally, the clashing power cable networks and telecommunication networks belonging to many entities were rebuilt.
Water main for 6 cities
“Interestingly, we also had to reconstruct the networks that belong to the “Murcki-Staszic” hard coal mine: the mine water canal, providing drainage of the mine, combined sewage system, a process water pipeline and a compressed air pipeline,” lists Adam Owsiany, NDI Project Director. “The biggest challenge in the road and bridge investment was the reconstruction of the water main that supplies six cities in the Upper Silesian agglomeration. The completed section has a diameter of 1.2 meters and a length of over 1,300 meters,” he adds.
The water main received a new pipeline and 10 inspection chambers. The sections on which it runs, located under the railway lines and the road system, were made using the microtunneling method in casing pipes.
DK 81 is ready
The progress of work can be seen with the naked eye, and drivers use the new, already commissioned infrastructure on a daily basis. Let us recall that until recently the National Road No. 86 used to have a dual carriageway cross-section. The section currently under construction (2.5 kilometres long) has two new main roadways and two merging lanes, which provide a connection with grade-separated slip roads serving both transit and local traffic.
“In the first stage, we built two new western roadways, which have already been opened to traffic. We are currently constructing both eastern roadways with their flyovers,” explains the NDI Project Director. ”We have already rebuilt National Road No. 81 over a length of 1100, with a double carriageway two-lane cross-section.”
The fifth slip road any day now
But one of the most important road investments in Katowice in recent years does not only involve road construction. In order to build the designed flyovers, the groundwork under each of the designed bridge supports had to be strengthened earlier. For this purpose, the innovative technology of strengthening the ground with “trench-mix” soil cement panels was used. Panels up to a depth of 9 meters were made. More than 1,000 DSM columns, reaching a depth of 14 meters, were also designed and implemented.
Two underground pedestrian crossings are also being built. Reinforced concrete works and drainage construction are currently underway. On both the eastern and western sides of DK86, there will be stairs and ramps that will be roofed. The plan also includes nine grade-separated slip roads. As early as November, drivers will be able to take the fifth slip road that has been put into use. It will lead the traffic from the centre of Katowice and Sosnowiec towards Skoczów and Wisła.
The intersection of Kolista, Karolinki and 73. Pułku Piechoty Streets is also being reconstructed. “In October, we started the next stage of the reconstruction of 73. Pułku Piechoty and Kolista Streets, under which a new stormwater drainage system will be built, as well as electricity and telecommunication networks. Then we will build a new road structure with pavements. There, the works are carried out using a “half-way” method, allowing road traffic in one direction,” says Adam Owsiany from NDI. ”We also performed works securing a deep excavation in sheet piling along with earthworks for the designed underground storage reservoir collecting rainwater from the rainwater sewage system.”
In the coming weeks, the assembly of the entire reservoir made of 3.6 m diameter pipes arranged in two rows with a total length of 86 meters and a capacity of 590 cubic meters is planned. It will be a completely underground reservoir.
All works on the DK86/DK81 junction will be completed by the middle of next year. The cost of the investment is approximately PLN 308 million, of which 244 million was obtained under the Operational Programme Infrastructure and Environment .