By rosebell
Including construction of a 16m-long tunnel, the stormwater project at Prague VH Airport in Ruzyně, which is designed to protect the airport from flooding, has been completed by Czech firm Subterra.
As part of the Metrostav Group, Subterra used an AVN Herrenknecht system for the first time at the rather unusual jobsite, directly inside the airport area.
Being used in mixed soil conditions, the AVN1200TC machine faced much stronger uniaxial compressive strength (UCS) than expected. While the initial selected cutterhead for the micro-TBM a mixed cutterhead capable of handling UCS of 25-50MPa, as work started, a much stronger UCS of up to 120MPa was discovered.
In order to solving this problem, at short notice Herrenknecht provided a rock cutterhead with an extension for a 1720mm diameter pipe from its rental department.
