Subcontracted to a consortium of lead firm A-Híd Építo Corporation, together with Közgép, Strabag MML, Magyar Aszfalt, and COLAS Hungária, specialist contractor HBM (Hídépíto Soletanche-Bachy Deep Foundation) is responsible for installing deep foundations for river bridges and overpasses on the scheme.
It has already installed - from barges and drilling pontoons - a selection of driven steel and LDA (rotary bored) piles for the project's biggest structure, the Háros Danube bridge.
The 11km-long highway extension includes eight bridges, two of them spanning the Danube. HBM is undertaking specialist foundation works for five structures: for the two Danube bridges and three overpasses. It is using several special deep foundation technologies from driven steel piling to D-Wall construction, traditional and CFA piling, and aquatic piling works - in various types of ground conditions.
The arrangement and movement of rigs had to be planned very precisely in advance, explains HBM, "in order to secure the balance of the aquatic equipment during the works". The placement of barges and a pontoon, the installation of the driving pipe for LDA drilling, and the cutting back of the driven steel piles by industrial divers, have all contributed to this being an unusual and challenging project.