H-33 Truss, modular and load-bearing solution in the construction of two bridges in Kraków

Two new bridges over the Vistula are under construction in Kraków: the M1 and M3. The first will be used by long-distance trains and the second by local trains. The separation of long-distance and local traffic will improve the passage of trains through the area considerably, allowing for an increase in service coverage, shortened journey times, and enhanced passenger comfort and safety.

These two new railway bridges in Kraków are part of the project entitled “Works on the E30 railway line, Kraków Główny Towarowy-Rudzice section, including the construction of metropolitan line tracks”. This is an investment of over one billion zł, co-financed by the Connecting Europe Facility (CEF), a funding instrument for European infrastructure investment, which will ensure the efficient travel of trains through the Kraków section of the international E30 route, which connects the cities of Przemyśl, Kraków, Wrocław, and Zgorzelec, among others.

The company in charge of managing the railway lines (PLK – Polskie Linie Kolejowe) planned three new railway bridges, and since 2020 trains have been able to cross the M2. The second crossing will be ready by the end of this year or early next year, and will have two tracks for long-distance trains. The third bridge will be for trains, pedestrians and cyclists.

Strabag is the general contractor for this project. ULMA Construction provided complete formwork, shoring and scaffolding solutions for all phases of construction and for the three structures M1, M2, and M3.

Construction work on the M1 and M3 bridges is currently underway. The M1 structure, which is the central bridge over which two railway tracks run, consists of four spans with a span between supports of: 30.9 m + 37.8 m + 36.3 m + 11 m = 116 m. The supporting structure of the formwork for three of the spans was built with a system designed to span the Vistula River with  heavy-duty H-33 Trusses measuring between 24 – 30 metres in length. This truss system is modular, requires minimal shoring, and is easy to both assemble and handle. The narrowest span is made of 12 m long TAC steel profiles. Both the trusses and the steel profiles were installed on the existing piers of the old bridge crossing the river bed, which was adapted for this purpose. The superstructure is attached to the piers by MK bracket assemblies and metal profiles responsible for the load distribution of the deck.

The shoring for the the supporting structures for the side spans of the M1 consists of T60 Shoring TowersALUPROP aluminium props, and heavy-duty S40 Props.

ENKOFORM HMK  was used for the bridge deck formwork, and proved to be a very versatile beam formwork system for various horizontal concrete structures that adjusted perfectly to the section requirements.

The M3 structure was designed using similar technology: a gantry falsework structure of H-33 Trusses, consisting of four spans identical to those of the M1. The 24 m span is designed with TAC 1200 steel beams, while the next two 30 m spans will be made with H33 Trusses and the last span will be made with 9 m long DIPE 450 steel beams. The TAC beams and H-33 Trusses are supported by MK Towers and S-40 Props, while the formwork is supported by T60 Towers and tall MK Towers. The side spans of the M3 structure will be built in the third quarter of this year.