A Study On Construction Arrangement Of Shield Tunnel Crossing Pedestrian Passage

Recently, the exploration and utilization of underground space have aroused extensively attention. Rock engineering varies with different geological conditions in cities nationwide. During the construction of shield tunnel, different geotechnical engineering problems will be also encountered. The influence of the construction under cities with soft soil foundation for the surrounding buildings is the key factor that affects the designation and construction. In some soft soil foundation cities, building subsidence and damage for the public facility caused by the shield construction have attracted more attention.This paper is based on the designation and construction of the first phase of the Xiamen number1subway project and illustrates the earth pressure balanced shield by comprehensively using shield construction theory home and abroad. And analyzing the shield construction under the pedestrian passage process by using finite element software FLAC3D numerical model, it is concluded that the vertical displacement, horizontal displacement, the distribution of maximum principal stress and related change rule under the shield construction at different stages in the process of the shield construction. In addition, by comparison and analysis whether need to grout reinforcement stress and settlement of the pedestrian tunnel beneath the soil, it is concluded that the necessary to grout reinforcement for the shield construction under pedestrian passage. Compared with the results of monitoring data, we can get the feasibility of construction arrangement for the shield construction under the pedestrian passage, and thus it can provide better guidance for the tunnel design and construction. Specific work can be concluded as following:(1) Investigation and analysis of the actual geological conditions, hydrogeological conditions and making decision of the safety construction technology measures for shield construction under pedestrian passage on the basis of the actual geological conditions and design supporting parameters.(2) To establish the FLAC3D model of the shield construction under pedestrian passage, analyzing before and after grouting reinforcement the change of the maximum principal stress, the vertical displacement and horizontal displacement in shield tunnel and pedestrian passage, getting the total settlement curve in pedestrian passage and the necessary of grouting reinforcement below the pedestrian passage to prevent the settlement.(3) Comparison the field monitoring measurement data and the results of numerical analysis, concluding shield tunnel and the pedestrian tunnel stability theory, thus to make sure the tunnel construction safety, and the feasibility of construction arrangement.