Three-dimensional finite-element analysis on ground responses during twin-tunnel construction using the URUP method

Abstract The paper presents a finite-element analysis of a metro tunnel project using the URUP method in which the shield machine is launched and received at the ground surface level. During the tunnelling process, the cover depth varied from 0.7D (D is the excavation diameter) to −0.3D in which case the shield machine was partially above the ground surface. A three-dimensional finite element model is proposed via the commercial software ABAQUS considering the actual geological condition and tunnelling procedures. Elasto-plasticity constitutive models are utilised for the top three strata in the finite element analysis (FEA). Constant gradients corresponding to material density are assumed for the face supporting pressure and the grouting pressure in the model. The ground contraction method is employed to simulate the shield-induced volume loss. The numerical model is firstly validated against the field measurement data considering the surface settlement. Parametric studies are performed subsequently to investigate the influence of some key tunnelling variables including cover-to-diameter ratio and face supporting pressure on the ground responses. According to the FEA, a critical cover depth of 0.55D is proposed for URUP method below which value instability and collapse of surrounding soils will be highly likely.

[1]  J. Xia,et al.  Cyclic variability in microstructure and physio-mechanical properties of the Xiashu Loess-palaeosol sequence in Nanjing, China , 2009 .

[2]  J. R. Standing,et al.  Greenfield ground response to EPBM tunnelling in London Clay , 2013 .

[3]  S. Shen,et al.  Long-term settlement behaviour of metro tunnels in the soft deposits of Shanghai , 2014 .

[4]  Adam Bezuijen,et al.  FIELD MEASUREMENTS OF GROUT PRESSURES DURING TUNNELLING OF THE SOPHIA RAIL TUNNEL , 2004 .

[5]  R. J. Fowell,et al.  EFFECTS OF DIFFERENT TUNNEL FACE ADVANCE EXCAVATION ON THE SETTLEMENT BY FEM , 2003 .

[6]  D. C. Drucker,et al.  Soil mechanics and plastic analysis or limit design , 1952 .

[7]  Robert J. Mair,et al.  SUBSURFACE SETTLEMENT PROFILES ABOVE TUNNELS IN CLAYS , 1993 .

[8]  Hiroaki Sugihara,et al.  URUP (Ultra Rapid Underpass) - TBM Excavation in Soft Ground from the Surface Elevation (Zero Overburden) Without Shaft and/or Large Scaled Open Cut Pit , 2013 .

[9]  Günther Meschke,et al.  A 3D finite element simulation model for TBM tunnelling in soft ground , 2004 .

[10]  Zhiguo Zhang,et al.  Geotechnical influence on existing subway tunnels induced by multiline tunneling in Shanghai soft soil , 2014 .

[11]  D. Festa,et al.  On the Interaction between a Tunnel Boring Machine and the Surrounding Soil , 2015 .

[12]  Daniel Dias,et al.  Probabilistic analyses of tunneling-induced ground movements , 2013 .

[13]  Charles Wang Wai Ng,et al.  Investigation of the Long-Term Tunnel Settlement Mechanisms of the First Metro Line in Shanghai , 2013 .

[14]  Toshiaki Nakamura,et al.  URUP (Ultra Rapid under Pass) Method the First Implementation in a Public Project , 2010 .

[15]  A. J. Beijer.  Ultra Rapid UnderPass: the adaption of the URUP method for the Netherlands , 2010 .

[16]  Shiming Wu,et al.  Design of shield tunnel lining taking fluctuations of river stage into account , 2015 .

[17]  Daniele Peila,et al.  Soil conditioning of sand for EPB applications: A laboratory research , 2008 .

[18]  R. Peck.  Deep excavations and tunnelling in soft ground , 1969 .

[19]  Wei Zhu,et al.  Opening the excavation chamber of the large-diameter size slurry shield: A case study in Nanjing Yangtze River Tunnel in China , 2015 .

[20]  Pierpaolo Oreste,et al.  Three-dimensional numerical simulation of a mechanized twin tunnels in soft ground , 2014 .

[21]  Hehua Zhu,et al.  A case history of shield tunnel crossing through group pile foundation of a road bridge with pile underpinning technologies in Shanghai , 2015 .

[22]  Daniela Boldini,et al.  3D numerical modelling of soil–structure interaction during EPB tunnelling , 2015 .

[23]  A. H. Oldenhave.  Starting a large diameter TBM from surface: Feasibility study for the Netherlands , 2014 .

[24]  Guy T. Houlsby,et al.  Advanced finite element analysis of a complex deep excavation case history in Shanghai , 2014 .

[25]  Xiaowu Tang,et al.  Ground movement induced by parallel EPB tunnels in silty soils , 2011 .

[26]  Kenichi Soga,et al.  Modelling of long-term ground response to tunnelling under St James's Park, London , 2007 .

[27]  Felix Nagel,et al.  Grout and bentonite flow around a TBM: Computational modeling and simulation-based assessment of influence on surface settlements , 2011 .

[28]  Richard A. Regueiro,et al.  Pile and pile group response to tunnelling using a large diameter slurry shield – Case study in Shanghai , 2014 .

[29]  Daniela Boldini,et al.  TBM tunnelling-induced settlements in coarse-grained soils: The case of the new Milan underground line 5 , 2013 .