Experimental study on face instability of shield tunnel in sand

Chen, Ren Peng; Li, Jun; Kong, Ling-gang; Tang, Lvjun

doi:10.1016/j.tust.2012.08.001

Cited by 279 publications

(62 citation statements)

References 25 publications

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“…The existing methods that have been used for evaluations of tunnel face stability include limit equilibrium [15], limit analysis [16,17], the displacement finite-element method [18], the discrete numerical method [19], scale model test [20][21][22], and centrifuge model test [23][24][25]. These methods have been proven to be useful in determining the limit support pressure and evaluating the effects of reinforcement measures.…”

Section: Introductionmentioning

confidence: 99%

Prediction of Tunnel Face Stability Using a Naive Bayes Classifier

2019

Applied Sciences

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This paper develops a convenient approach for facilitating the prediction of tunnel face stability in the framework of Bayesian theorem. First, a number of values of the features influencing the face-stability of tunnels are chosen according to the full factorial design. Secondly, the software OptumG2 is utilized to performed strength reduction analyses to obtain safety factors regarding tunnel face stability. Based on the simulated safety factors, the chosen samples are labeled as stable (Fs≥1) or unstable samples (Fs<1). Thirdly, the model parameters that characterize the distribution of the random variables are then estimated by maximizing the well-known likelihood function. After that, the probability density functions (PDF) of the features are identified, and a naive Bayes classifier is constructed with the prior probabilities of the stable and the unstable state. The so-called type І and type І І errors are estimated with stable and unstable samples, respectively. The model parameters are then calibrated with additional stable samples to obtain the second classifier. Finally, the two classifiers are evaluated using independent samples that have not been seen in the training dataset. The proposed method allows geotechnical engineers to predict the stability of tunnel faces with great efficiency. It is applicable for general cases of tunnels where the parameters are within the ranges bounded by the specified values.

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Section: Introductionmentioning

confidence: 99%

Prediction of Tunnel Face Stability Using a Naive Bayes Classifier

2019

Applied Sciences

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“…Studies using limit equilibrium or limit analysis methods were used for the analysis of the tunnel face stability [2][3][4]. Experimental studies were also conducted to explore excavation stabilities [5]. Lee et al [6] analyzed the evolution of arching effects on the soil mass surrounding tunnels.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study of the Behavior of Rectangular Excavations Supported by a Pipe Roof

2019

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This paper presents an experimental investigation of the role of pipe-roofs in the improvement of the stability of rectangular excavations constructed using pipe-roof technology. This technology is suitable for the construction of underground passages in crowded areas subjected to high requirements concerning soil settlement and stability during excavation construction. The design of a rectangular pipe-roof excavation required an understanding of the interaction between the soil, the pipe-roof and the excavation. This interaction is complex and plays an important role in the features of the pipe roof excavation. This paper presents a series of 1g physical experimental tests conducted in dry sand soil with an advanced monitoring system, which allows tracking of the soil settlement, the pipe deformation and the soil pressure. Analysis of these tests shows the effective role of the pipe-roof in reducing both the soil settlement and the soil pressure on the excavation. It also shows the influence of pipes on the deformation mechanism of the soil and its evolution from low deformation to the instability phase.

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“…Based on 3D FEM simulations, Lu et al (2014) considered the influence of seepage on the face stability and analyzed the relationship between the support pressure and displacement of the shield tunnel face. Chen et al (2013) conducted numerical simulations of the tunnel face failures using the 3D FDM and compared the results of the limit support pressure with those obtained from their experimental tests. Senent et al (2013) proposed a model with the 3D FDM to analyze the tunnel face failures in fractured rocks under two different distributions of normal stresses along the slip surface.…”

Section: Introductionmentioning

confidence: 99%