Abstract:

The Shichahai StationNanluoguxiang StationChina Art Gallery Station section on Line 8 of Beijing Metro is a smallspaced longdistance shiedbored stacked tunnel section. The tunnel crosses underneath buildings. The construction principle of “upper tunnel tube bored first and lower tunnel tube bored later, keeping some horizontal distance between the face of the lower tunnel tube and that of the upper tunnel tube, and supporting the lower tunnel tube by supporting trolley” is followed for the mentioned tunnel section. Key construction technologies, including shield boring parameter control, consolidation of soil between the upper tunnel tube and the lower tunnel tube by means of grouting, supporting the lower tunnel tube by temporary supporting trolley, are adopted in the construction of the mentioned tunnel section, so as to guarantee the safe and successful construction of the stacked tunnel. The monitoring and estimation made show that the technologies used are rational and proper. The paper can provide reference for the construction of similar stacked shieldbored tunnels crossing underneath buildings in the future.

Key words: longdistance stacked tunnel, shield tunneling, continuous boring underneath old buildings