Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
3D large-deformation modelling on face instability and sinkhole formation during tunnelling through non-uniform soils
Highlights Large-deformation modelling is conducted to study tunnelling-induced sinkhole. Spatial non-uniformity greatly affects face stability and sinkhole hazards. Deterministic analysis underestimates probability of failure of tunnel face. Consequence of sinkhole hazards is significantly underestimated in uniform soils.
Abstract Natural soils exhibit spatially non-uniform properties, bringing some uncertainties on the evaluation of tunnel stability. This study therefore investigates the face instability and in particular to the sinkhole formation in spatially non-uniform soils by conducting large-deformation finite-element (LDFE) analyses combined with a three-dimensional random field. The results from LDFE analyses indicate that soil spatial non-uniformity greatly affects the failure mechanism as well as the face stability. The stability factor in non-uniform soils is averagely smaller than the deterministic solution in a uniform soil, implying the assumption of uniform soil conditions likely underestimates probability of failure of a tunnel face. With regard to the sinkhole behaviour, the average ground settlement obtained from random analysis is greater than that from deterministic analysis. This underscores the necessity of considering the soil spatial non-uniformity in the analysis of the sinkhole behaviour. This study provides an improved understanding on the face stability and sinkhole formation during tunnelling through non-uniform soils.
3D large-deformation modelling on face instability and sinkhole formation during tunnelling through non-uniform soils
Highlights Large-deformation modelling is conducted to study tunnelling-induced sinkhole. Spatial non-uniformity greatly affects face stability and sinkhole hazards. Deterministic analysis underestimates probability of failure of tunnel face. Consequence of sinkhole hazards is significantly underestimated in uniform soils.
Abstract Natural soils exhibit spatially non-uniform properties, bringing some uncertainties on the evaluation of tunnel stability. This study therefore investigates the face instability and in particular to the sinkhole formation in spatially non-uniform soils by conducting large-deformation finite-element (LDFE) analyses combined with a three-dimensional random field. The results from LDFE analyses indicate that soil spatial non-uniformity greatly affects the failure mechanism as well as the face stability. The stability factor in non-uniform soils is averagely smaller than the deterministic solution in a uniform soil, implying the assumption of uniform soil conditions likely underestimates probability of failure of a tunnel face. With regard to the sinkhole behaviour, the average ground settlement obtained from random analysis is greater than that from deterministic analysis. This underscores the necessity of considering the soil spatial non-uniformity in the analysis of the sinkhole behaviour. This study provides an improved understanding on the face stability and sinkhole formation during tunnelling through non-uniform soils.
3D large-deformation modelling on face instability and sinkhole formation during tunnelling through non-uniform soils
Chen, Xuejian (Autor:in) / Hu, Yao (Autor:in) / Zhang, Lei (Autor:in) / Liu, Yong (Autor:in)
16.01.2023
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Face stability , Sinkhole formation , Large-deformation modelling , Spatial non-uniformity , Probability of failure , <italic>c</italic> , Cover depth of tunnel , <italic>C</italic> <inf>d</inf> , Wave velocity of Euler material , <italic>D</italic> , Tunnel diameter , <italic>E</italic> , Young’s modulus , <italic>f</italic> , Field variable , <italic>H</italic> , <italic>D</italic>epth at tunnel axis , <italic>F</italic> , Contact force between Lagrangian body and Euler element , <italic>h</italic> <inf>min</inf> , Minimum mesh size , <italic>k</italic> <inf>0</inf> , Initial geostatic stress factor , <italic>k</italic> <inf>i</inf> , Penalty stiffness coefficient in CEL method , <italic>L</italic> , Collapse distance of tunnel face , <italic>L</italic> <inf>e</inf> , Characteristic size of Euler element , <italic>N</italic> , Number of Monte Carlo simulations , <italic>N</italic> <inf>c</inf> , Stability factor in uniform soils , <inf>ran</inf> <italic>,</italic> Stability factor in non-uniform soils , <italic>p</italic> , Probability of Failure , <italic>P</italic> , Critical support pressure in uniform soils , <italic>P</italic> <inf>ran</inf> , Critical support pressure in non-uniform soils , <italic>S</italic> , Source term in Eulerian formulation , <italic>s</italic> <inf>u</inf> , Shear strength of non-uniform soil , <italic>s</italic> <inf>u0</inf> , Shear strength of uniform soil , <italic>w</italic> , Ground settlement , <italic>γ</italic> , Unit weight , <italic>φ</italic> , Friction angle , <italic>Φ</italic> , Cumulative normal function , <italic>ψ</italic> , Dilatancy angle , <italic>ν</italic> , Poisson’s ratio , <italic>ϕ</italic> , Flux function , <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>u</mi> <msub><mi>N</mi> <mtext>c,ran</mtext></msub></msub></math> , Mean stability factor in non-uniform soils , <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>σ</mi> <msub><mi>N</mi> <mtext>c,ran</mtext></msub></msub></math> , Standard deviation of stability factor in non-uniform soils , <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>u</mi> <msub><mi>s</mi> <mtext>u</mtext></msub></msub></math> , Average undrained shear strength in non-uniform soils , <italic>Θ</italic> <inf>H</inf> , Correlation length in horizontal direction , <italic>Θ</italic> <inf>V</inf> , Correlation length in vertical direction , Δ<italic>x</italic> , Displacement of anchor points punching through the Lagrange surface nodes in CEL method , <italic>t</italic> , Time step in CEL model , Δ<italic>t</italic> <inf>crit</inf> , Critical incremental step , 2D , Two-dimensional , 3D , Three-dimensional , CEL , Coupled Eulerian-Lagrangian , COV , Coefficient of variation , EVF , Eulerian volume fraction , FEM , Finite element method , LFDE , Large-deformation finite-element , MPM , Material point method , SPH , Smoothed particle hydrodynamics
Face instability in tunnelling through thick fault zones
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Criteria of sinkhole formation in soils from physical models
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