Description
Located in the south of Poland, the 34 km long Motorway A4 connects the cities of Krys and Debica. The bridge over the Wisłoka River or Overpass E118 is with 1,350 m the largest structure of the motorway.
This overpass is divided into three sections and has two carriageways, with one being straight and the other being a constant curve.
ULMA solution
The characteristics of the design required the use of two construction systems: the conventional with T-60 and the incremental launching method. This was the first time that a bridge with a deck of two inner cross-sectional hollows has been constructed in Poland. The proposed solution made it possible to build stretches of 30 m a week, so that the construction time for each segment was reduced by 50 %.
ULMA designed and supplied the formwork for the entire concrete structure as well as for the four fixed pre-fabrication areas where the incrementally launched segments were manufactured.
The bottom of the bridge deck was built with the MK System covered with plywood. MK offers solutions for this, as for many other types of applications with the use of standard material.
As wing formwork, ENKOFORM HMK beam-based formwork was used.
The bridge deck construction was carried out in two stages. The first stage consisted in the pouring of the lower slab of the bridge deck together with the side walls. In the second stage, the top slab was poured. The solution offered by ULMA allowed building the 32 segments, each of 30 m, of both bridge decks in weekly cycles.
To ease the works under adverse weather conditions and improve the hardening of the concrete, a temporary roof covering fixed pre-fabrication areas was installed. This was done with BRIO Modular Scaffolding supported on MK towers and moved on rails.
For this stage no shoring between piers was required. This allowed developing a simple procedure, without powerful auxiliary means and a minimum effect on the environment.
ULMA did not only get involved in the construction of this bridge, but supplied material for other 13 civil engineering structures on the A4 Motorway.
