From the autumn of 2015 to this February, we were working on repairing damages to the lower quays of Buda and Pest inflicted by the 2013 flooding. The job was ordered by Fővárosi Csatornázási Művek Zrt., and affected both banks of the Danube section constituting one of Budapest’s world heritage sites.

As part of the project, we fixed the subsided areas on the slope pavement near the water outlets of the Pest-side bank, as well as the limestone retaining wall belonging to the downstream-side ramp at the foot of the Margit Bridge. In order to refurbish the upper quay’s retaining wall, we carved back the deteriorated, crumbling parts and the grouting, and we carried out similar renovation works on the stone steps near the Margit Bridge. On the section along the Danube Promenade, we also reconstructed the retaining walls adjacent to the tram station. The wall structure near the Vigadó Square water-level gauge underwent complex refurbishment with the help of stone-restoration experts. At the lower quay of the Buda-side bank, we performed similar reconstructions on the retaining walls between the Szabadság Bridge and the Széchenyi Chain Bridge. The upper sections of both steps near the Erzsébet Bridge were severely damaged, and thus needed thorough repair works.

Colas Alterra restored the flood-control retaining wall located near the Szentlélek Square commuter railway station as well. The project was ordered jointly
by the BKK (Centre for Budapest Transport) and Fővárosi Csatornázási Művek Zrt. As the retaining wall that separates the station from the lower quay constitutes a part of the flood-control system, it often needs vertical extensions during heavier floods. The existing wall was no longer capable of fulfilling its function, and will thus be replaced with a new structure. We have already demolished the old wall, and the construction of a new flood-control structure is currently in progress on a complete length of nearly 360 m. The slurry wall foundation is composed of 60-cm-wide units, some of which reach down to a depth of 7 metres, and a 40-cm-wide wall is to be built on the top. The new retaining wall is higher than the old one – consequently, it provides a more effective protection against floods. In addition, it can be heightened by another 80 cm with the use of mobile flood-barrier units. For the sake of soil stability, we are preparing so-called dry slots. The deepening of the slots is performed in a chessboard pattern, with 3- and 7-m-deep slots following each other. For the duration of the concreting, we installed separating steel structures between the slots, which leave a semicircular imprint on the side of the concrete slabs following removal. This has a favourable effect on water-blocking capability and aids the load transfer between the sections. The wall will be built onto the completed foundation with expansion joints every 15 metres. On top of the retaining wall, mounting plates are to be installed (3 metres apart) for the posts of the mobile barrier system. If required, the mobile units can be attached to these fittings, and the height of the structure can be extended by 80 cm. The posts are connected with 20-cm-high steel beam inserts with an interlocking saw-tooth pattern, and sealing is solved with
EPDM rubber profiles.