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Abstract It is difficult to properly simulate the whole excavation process during slurry shield tunneling and also to exactly explain its corresponding modeling results. Combined with the complex ground condition in Qianjiang tunnel and Shanghai Yangtze tunnel，the paper suggests a more comprehensive numerical simulation method to describe the characteristic of the whole tunneling process，and with respect to the modeling results handling，the mechanical property and its microscopic structure are connected to quantitatively analyze the face failure mechanism and estimate the mechanical behavior step-by-step. The main results show that：the discrete numerical approach can be considered as an effective way to model the excavation problem for the whole slurry shield process；for example，the volume of excavated soil is well proportional to the soil density and the pressure exerted on excavation face，i.e.，when the stiffness of the particle is larger than that of the wall，then soil is excavated under the pressure；contrariwise，the shield stops tunneling. The research results are well applied to the background projects and good results are achieved；and the established particle flow code(PFC) approach for the whole tunneling process also provides a reference for similar projects.
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Received: 20 May 2013
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2013, Vol. 32 
