A single-span viaduct with two tracks and a turnout – the first of its kind in Poland.

As part of the contract for the reconstruction of the Warsaw West station, Budimex completed a railway viaduct located at 4+787 km on railway line No. 1. The single-span structure – 118.5 m long and 16.5 m high – weighs 1,700 tonnes and was built as a single element using incremental launching technology. The viaduct is a unique construction on a national scale; it was built as a single superstructure for two railway tracks, including a turnout. This solution had never been used before in this type of contract. The manufacturer of the construction is Mostostal Kraków.

Works on the construction of the new viaduct began in May this year, and passengers arriving in Warsaw West from the direction of Włochy and Jerozolimskie Avenue could watch the steel structure of the viaduct being slid on in autumn.

The size of this facility can be compared to a five-storey apartment building. Its weight is the equivalent of a cargo train with 25 wagons loaded with coal. In turn, the surface area of the facility reaches the size of 13 volleyball courts.

The structure was slid into its final location so that the old reinforced concrete viaduct would be demolished from underneath before the end of October. The steel construction was founded on reinforced concrete supports, for which more than 20,000 m3 of excavation was carried out, and placed on more than 450 pieces of prefabricated driven piles with a total length of more than 4 km.

The steel structure of the new viaduct was delivered in components and integrated on-site behind the north support. The structure manufacturer Mostostal Kraków produced and delivered it on time. The facility is designed as a bottom-running lattice structure, in which the top and bottom lanes have a box section, while the diagonals and bracing have a box section and I-section. The utility deck of the facility is an orthotropic deck. This type of deck provides greater strength and can carry heavier loads.

Noteworthy is the fact that the steel structure weighs 1,700 tonnes. The process of sliding it took five days in total and was divided into two stages. For technological reasons, approximately two months were needed between the two slip-on stages to complete the integration of the steel structure. It was cantilevered over an existing reinforced concrete structure and three active railway lines. Interestingly, we used the structure of the old building, which we had properly prepared for this purpose, says Jakub Konkiewicz, Warsaw West Contract Director at Budimex.

The main objectives in the design and construction of the viaduct were:

• ensuring that construction phasing/staging is maintained in accordance with the construction project,
• limitation/reduction of making temporary adjustments to the phasing of the works conducted under the viaduct due to the possibility of carrying out the works independently,
• minimising disruption to ongoing train traffic running continuously, in particular, under the facility.

Warsaw West is one of the largest investments issued by PKP Polish Railway Lines (Polskie Linie Kolejowe S.A.), with a net worth of over PLN 1.9 billion. Warsaw West is, at the same time, a strategic station in Poland in terms of the number of trains running there. On average, about 1,000 agglomerative, regional, long-distance national and international trains pass through it every day. The project is implemented under POIiŚ 5.1-13 project, under the name of: “Works on the Warsaw cross-city line between Warsaw West and Warsaw East”.