Study On Ground Surface Settlement During Construction Of Beijing Huangzhuang Subway Station Cut By Right-angled Intersection Method

The ground surface settlement control is the most important problem for construction and environment safe during subway excavation under city road. Huangzhuang Station, the subway interchange station of Beijing subway line 10 and Beijing subway line 4, is the first cross interchange transition station which is built by the whole underground excavation technique in china and it is the biggest mining station so far. The land subsidence control is the difficulties and emphases of the construction and security environment during the construction period. Based on the theory analysis, engineering analogy, field test, and information feedback and so on, this thesis shows ground surface settlement by developing system research task and studying subjects. And the detailed contexts are as follows,Aiming at the difficulties and characteristics of the subway interchange station which was built by whole underground excavation, a new technology of Top-down Bored Excavation with Cast-in-Situ Arch is put forward based on the mechanics analysis of tunnel construction. Compared to traditional CRD method, CD method and two-side-wall pilot tunnel method by the theoretical and positive analysis, this method is with the following advantages, prominent ground surface settlement control, structural stability and construction safety.According to the further study of cross node mined work, the using function of subway station, the calculating result of digital model and the stress characteristics, a mode of’Double straight wall with single curved wall’cross node mined work was put forward, this structure has the following advantages:stressing definite, the reliability of ground surface settlement control, the low construction risk, the increased impacts on environment of the station and the existing underground structure.Supervision system of informative construction is designed and set up. It supervised the influence degree of ground settlement, stress and strain field, lines and structure. By information monitor control technique, it guides the security management during the construction period. According to field test data, it constructs model of front and back analysis of displacements and predate settlement effectively. This shows its applicability to the feedback analysis of information construction.The model of pipe roof calculation was corrected by studying the features, the mechanism and the construction technique of pipe roof. Using the new idea of a pile element’s simulation to pipe shed, the influence law of control ground surface settlement for pipe roof is available.Based on the bell-spigot joint and the welded joint of underground pipeline, the corresponding relation between the ground surface settlement and the state of underground pipeline was established by analysis and calculation of the different location between the pipeline and the tunnel. And the ground settlement of pipeline was analyzed. According to the standards of parallel control of pipeline, the standards of ground settlement were established and the standard ensured the security of the subway and underground pipeline.The above research results not only guides the construction safety of Huangzhuang Station directly, but also gets the marked benefit of economy, society and environment. And it has significant influence to developing the technique of construction industry and plays a remarkable guiding role in developing the design level of underground structure.