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| Study of Soil Deformation Caused by Construction with PBA Method |
| HUANG Sheng-gen1, FU Zhuo1, WU Jun-lin2 |
| (1.China University of Geosciences, Wuhan, Hubei 430074, China; 2.Southwest Geotechnical & Design Institute of China Nuclear Industry, Chengdu, Sichuan 610061, China) |
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Abstract Abstract：Research purposes： As a new method of metro station construction, the pile-beam-arch(PBA) tunneling method is developing rapidly. Neglecting the interaction between underground structure and soil, existing research results mainly focus on surface settlement and pipeline deformation. In particular, there is a lack of research on soil deformation caused by the construction of holes and piles in the four-hole and three-span structure. Based on the Suzhou Street Station of Beijing Metro line 16, the law of surface subsidence in the phase of pilot tunnel excavation was studied through the date of field monitoring. Metro station construction was dynamically simulated with FEM to study soil deformation during the construction in the four-hole and three-span structure. Research conclusions： (1) "Effect of group cavities" will appear when a plurality of adjacent pilot tunnels are excavated together. (2) Pilot tunnel excavation, construction of first and second lining have the greatest impact on surface subsidence. The proportions of settlement are 32%, 55% and 7%. (3) Supporting system formed after finishing secondary lining construction. In addition to the bottom soil that has vertical upheaval due to unloading after excavation, the other soil mainly was mainly horizontal deformation. After station construction, certain horizontal displacement that moves to the center of station raised in the soil over the vault. Horizontal displacement, caused by stretching deformation of the supporting structure, toward the outside station obvious took place in the soil on both sides of the vault and the soil around the pile end moved to metro station. (4) The conclusion can provide a theoretical basis for the popularization and application of the pile-beam-arch(PBA) tunneling method and provide a reference for similar projects in the construction and design.
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Received: 15 November 2017
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2018, Vol. 35 
