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Abstract Taking the metro station in Beijing as the project background，the study of stratum displacement has been performed based on the deflection distribution control method. The effective control measures are proposed to reduce the impact on the surrounding environment. The results show：(1) Mechanical response of the pile-beam- arch(PBA) method between strata and station structure can be divided into four processes of unloading-loading，the pilot excavation and support and supporting arch are the key points which caused surface subsidence. (2) Before pilot excavation，the surrounding strata is reinforced timely by advanced grouting. The measures are performed such as malposition excavation，short footage and tough supporting to reduce the adverse impact on the surrounding environment. (3) The stress adjustment is performed between formation and station structure in the supporting arch stage. The structure would produce a certain coordination deformation and long stress adjustment process. Due to larger settlement rate，the measures are suggested such as setting the horizontal steel support，short footage and reinforcement strata. (4) The range of plastic zone around station increases gradually with the construction development，especially pilot excavation and supporting arch stage. (5) Comparison of surface settlement rate of four construction stages，the numerical calculation rate is 4.5∶1∶6∶1 and the in-situ monitoring rate is 4.3∶1.6∶5∶1，the results show they are consistent.
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Received: 24 August 2012
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2013, Vol. 32 
