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| Safety evaluation of construction schemes for underground excavated metro tunnels passing existing railway station yards |
| TAO Yonghu, RAO Junying*, XIONG Peng, PENG Hao, NIE Chongxin, ZHAO Changjie, PENG Xing, KONG Deyu, WANG Yaqi
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| School of Civil Engineering, Guizhou University, Guiyang 550025, Guizhou, China |
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Abstract When the subway goes under the station building of the railway station, it is easy to cause surface settlement, which in turn leads to instability of confining pressure, difficulty in construction, and increased costs. For engineering construction, it is still necessary to study the construction mechanics behavior in the underpass section. Based on Guiyang Metro Line 1 Railway Shachong Road Station Section(Huo-sha Section), combined with the numerical simulation software FLAC3D to establish an analysis model of the tunnel passing through the train station, and study the subgrade settlement changes, dark the internal force and safety factor of the lining structure in the excavation section. The results showed: with the gradual excavation of subway tunnels, the subgrade settlement of the railway station yard gradually increased, but it did not exceed the existing railway deformation control standards in the underpass section; after the construction of the secondary lining structure, the longitudinal distribution of the existing railway settlement was approximately a normal distribution curve, consisted with the change law of the surface settlement trough proposed by Peck, and the settlement range was from -50 to 50 m; the stress of the masonry structure was mainly concentrated on the wall waist and vault of the interval lining structure, the deformation types of the secondary lining structure were large eccentricity and small eccentricity, the axial force value gradually increased from the vault to the foot of the wall to both sides, and the two sides were basically symmetrical, the maximum axial force appeared at the foot of the wall; after the deformation of the secondary lining structure was stable, the maximum settlement value of the roadbed settlement at the intersection was 2.87 mm, which met the deformation control standard of the existing railway under the station yard.
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Published: 25 February 2021
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