Abstract: The construction speed, safety and working environment of the urban rail transit tunnel project in Qingdao located mainly in slightly-moderately weathered rock stratum should be improved, and the risk and environmental control in the construction process should be strengthened. The Phase I Project of Qingdao Metro Line 2 is characterized by short route, small curve radius and complex construction organization, and the external environment of the Project is characterized by shallow burial depth, various geological conditions and dense surrounding buildings. Therefore, the research and development of equipment, tunnel structural type and site construction scheme of double-shield TBM in urban rail transit tunnel are studied. The first compact double-shield TBM for urban rail transit is developed and manufactured, the structure of the tunnel with double-shield TBM is designed, and the technical schemes for launching, station-passing, transition and rapid construction of double-shield TBM are proposed.

Key words: double-shield TBM, urban rail transit tunnel, TBM selection, TBM design, lining structure, civil construction method