News from Vienna, Austria – On April 21 local time, the 4-meter-class Kelly-type hard rock tunnel boring machine “CREC 1071", developed by China Railway Engineering Equipment Group under China Railway Hi-Tech Industry, successfully completed the tunneling task of the main tunnel of the Kuehtai Hydropower Station Diversion Project in Austria with a single-head tunneling distance of 22.6 kilometers, achieving precise breakthrough.
The diversion tunnel project is located at an average altitude of 2020 meters, consisting of one main tunnel and three branch tunnels, with the total length of the main tunnel reaching about 25.6 kilometers. The tunnel mainly passes through biotite plagiogneiss strata, with an average rock compressive strength of 104 MPa and a maximum uniaxial compressive strength up to 166 MPa. Meanwhile, the construction overcame multiple difficulties including long-distance hard rock tunneling, crossing multiple fault fracture zones, and long-distance ventilation of small-section tunnels.
In response to various construction challenges, China Railway Engineering Equipment Group customized a 4-meter-class Kelly-type hard rock TBM for the project. Compliant with European CE standards, the machine adopts multiple innovative functional designs, greatly improving its safety, stability and adaptability under harsh conditions such as high altitude, hard rock and complex geology. After the equipment arrived at the construction site in November 2021, the technical service team of China Railway Engineering Equipment Group efficiently completed equipment assembly, commissioning and the whole tunneling process. During construction, the machine achieved excellent performance with a maximum monthly advance of 1067 meters and a maximum daily advance of 63 meters, effectively ensuring the scheduled tunnel breakthrough.
