An important moment in work at the DK86/81 junction in Giszowiec

By the end of the summer holidays, a 700-metre-long section of the western lane of DK 86 towards Tychy will be opened to traffic. Within a few weeks, the NDI Group also plans to open to vehicles the grade-separated junction that connects the national road 81 with the national road 86.

“Eighty-six” is one of the most frequently used national roads in Poland. Before the commencement of work, about 55,000 vehicles passed through it every day. The investment carried out in this place consists, among others, in the expansion and reconstruction of the section of Pszczyńska Street (DK-86), the section of 73 Pułku Piechoty Street (DK-81), the old route of 73 Pułku Piechoty Street, construction of a road junction at the intersection of DK-86 (Pszczyńska Street) with DK 81 (73 Pułku Piechoty Street), expansion of the Kolista road junction and reconstruction of the section of Kolista Street and Karolinki Street. The investor is the Katowice City Hall.

“I am very glad that another important road investment in Katowice is taking real shape. We are constantly striving to clearly separate the transit traffic from the inner-city traffic, which will be most beneficial for the residents, and the grade-separated connection is an important element of this enormous undertaking. Completion of works on the extension of the National Road 81 from the junction of the A4 motorway with the national road 86 will be the key to a new, much more efficient communication system of the city,” says Marcin Krupa, Mayor of Katowice.

“We are currently building both eastern lanes of the National Road 86. The construction of three flyovers: W2, W3 and W4, designed along this road is also in progress. The flyovers pass over the railway lines and over Kolista Street. We also carry out earthworks, strengthen the existing embankment between the structures W1 and W2, and construct a road surface structure on the road sections of DK-86. In addition, we make two underground passages in monolithic reinforced concrete technology,”  reports Adam Owsiany, NDI Project Director. He also announces that in September, a grade-separated junction (connecting DK-81 and DK-86) will be opened to traffic, enabling entry from 73 Pułku Piechoty Street to Pszczyńska Street in the direction of Tychy, and by the end of the summer holidays, a 700-metre-long section of the western roadway DK-86 towards Tychy, from the flyover over Kolista Street to the intersection with Górniczego Stanu Street.

State-of-the-art technologies are used in the course of the works. Last week, the soil strengthening in the area of the second flyover was completed – an innovative method, the so-called “trench-mix”, is used there. The substrate at the third flyover was also strengthened in a similar way.

“We used an innovative method, which consists in strengthening the soil by deep mixing with a machine called “trencher”. This machine mixes the cement slurry with the excavated material,” says Robert Tuleta, NDI Bridge Work Manager. “We wanted to adapt the work methods to the field conditions. Here, where there is a significant stratification of the subsoil, this technology is the most effective, because thanks to it we will obtain a uniform cement-soil material.”

In this way, soil-concrete panels are made under each of the bridge abutments and pillars. The designed depths of the reinforcements are from 4 to 9 metres.

Several methods of strengthening a weak subsoil are used in the investment under construction. In addition to the innovative “trench-mix”, DSM columns and traditional soil replacement are also used (they were used, for example, in reinforced concrete underground passages)

“In turn, on road sections, as part of additional works, we are strengthening the existing DK 86 embankment with DSM columns. This reinforcement is up to 14 metres deep, and the designed length of the columns is 14,000 metres. This is a job for the next two months,” explains Adam Owsiany, NDI Project Director.

Importantly, at the moment, the works are carried out according to the schedule. The already completed works include the construction of both lanes of the national road 81 with a length of 1 km. The underground utility networks, which collided with the planned road system, were rebuilt, as well as heating, gas, telecommunication, power networks and networks belonging to the KWK Murcki-Staszic mine.

“We are at the last stage of switching the water main, which is owned by Górnośląskie Przedsiębiorstwo Wodociągów. As part of this investment, we are rebuilding the network with a length of over 1,300 metres. We are in the last phase of work, at the junction W4,” says Adam Owsiany.

The thoroughfare runs from south to north, supplying several cities in the Upper Silesian agglomeration.

The investment is not easy because, as the contractor, we must ensure that the continuity of road and rail traffic is maintained at every stage of the works.

The cost of the entire investment amounts to PLN 247.5 million, of which 210 million was granted under the Infrastructure and Environment Operational Programme.