First 602-tonne TBM Launched on Northern Section of Bucharest Metro Line 6 in Romania

en.Wedoany.com Reported - On October 21, Romanian metro operator Metrorex announced that the first earth pressure balance (EPB) tunnel boring machine (TBM) for the northern section of Bucharest Metro Line 6 had begun excavation at the Brussels Station construction site, marking the entry of the Tokyo Station–Otopeni Airport section into the TBM construction phase. The equipment has a total length of 103 meters, weighs 602 tonnes, has a cutterhead diameter of 6.57 meters, and is designed for an average daily advance of 14 meters. The northern section is 7.6 kilometers long and includes 6 stations; the civil structure works are being carried out by a joint venture comprising Turkey's Gülermak and Romania's Somet.

The TBM launched this time is named "Saint Paraskeva" and will first undertake excavation of the first tunnel of the northern section, boring from the launch shaft at Brussels Station toward Tokyo Station. The second TBM, "Saint Catherine," will be responsible for the other tunnel. After completing the first-phase excavation, the two machines are planned to be relaunched from Brussels Station toward Otopeni Airport to form a twin-tube underground section.

The "Saint Paraskeva" TBM uses earth pressure balance technology; its total weight comprises a 380-tonne main machine and 222 tonnes of backup gantry cars. The construction alignment passes through sandy clay, the Colentina gravel layer, and silty sand strata, with the groundwater table at a depth of approximately 2 to 7 meters. The TBM is planned to advance an average of 14 meters per day, completing the assembly of 10 rings of precast concrete segment lining, with each ring 1.4 meters wide. The equipment installs the tunnel lining segments simultaneously during excavation and muck removal.

The northern section of Metro Line 6 includes 6 stations—Washington, Paris, Brussels, Otopeni, Ion Brătianu, and Otopeni Airport—and connects with the southern section at Tokyo Station. The civil structure works for the northern section are being implemented by the Gülermak–Somet joint venture, with funding from the Romanian state budget and a loan from the Japan International Cooperation Agency. The project began transporting TBM components in early October, completed preparations for lowering the equipment into the shaft on October 18, and subsequently entered the current mechanized excavation phase.

According to construction progress published by Romanian transport authorities on October 21, the southern section of Metro Line 6 is approximately 78% complete, and the northern section approximately 34% complete. The southern section has already carried out TBM excavation and underground structure construction in multiple running tunnels, while the northern section has entered the mechanized tunnel excavation phase with the launch of the first machine.