Construction, Monitoring, and Analysis: Guiyang Metro Line 1, China

Abstract The Huo-Sha Tunnel of Guiyang Metro Line 1 in China, which runs from the Guiyang Railway Station to the Shachong Road Station, passes through the railway station platform closely. The minimum distance between the vault and the pile foundation is only 2.19 m. The geology is complex, and the settlement control requirements for the oblique sections, platforms, station buildings, pile foundations, and existing buildings are remarkably strict. Comprehensive measures of “super pipe shed support, surrounding rock reinforcement, inverted arch grouting, and lining strengthening are strictly adopted” to prevent the influence of construction on the operation of station buildings and in-service railways, high-speed railways, and other buildings. It also analyzes the changing laws of the existing building subsidence, subgrade settlement, station longitudinal displacement variation, and the development trends of lining safety, stability, eccentricity, compression types, and internal force of the lining. The following results are presented. The Huo-Sha Tunnel is gradually excavated. The roadbed settlement of the Guiyang Railway Station platform gradually increases but does not exceed the existing railway deformation control standards for the subsurface excavation section. The longitudinal distribution of the existing railway settlement is approximately a normal curve after the construction of the secondary lining. This result is consistent with the law of the surface settlement trough proposed by Peck, and the range is between −50 m and 50 m. The stress of the lining is mainly concentrated at the arch waist and the vault, the compression types include large and small eccentric, the axial force value gradually increases symmetrically from the vault to the arch footing, the maximum axial force appears at the arch footing, and all control indicators meet the corresponding control standards. The subgrade settlement of the skew section meets the deformation control standards of the existing railway of the subsurface excavation sections after the stabilization of the secondary lining deformation.