Influence of soil conditioning on ground deformation during longitudinal tunneling

Soil conditioning is often adopted to facilitate EPB shield tunneling. However, the resulting improvement of soil fluidity and the reduction of friction forces will also raise the ground deformation problem. This paper aims to investigate the influence of soil conditioning on the ground deformation during longitudinal tunneling. DEM is employed for this study due to its advantages in analyzing large deformations and discontinuous processes. Soil conditioning is modeled by reducing the interparticle friction of soils in a specific zone around the cutterhead of the tunnel. The tunnel advance with different soil-conditioning treatments is thus modeled. Comparisons are carried out on the ground deformation, i.e. ground surface settlement, vertical and horizontal displacements. The influence of soil conditioning on the ground deformation is clarified, and is associated with the fluidity from poor to favorite, and the mechanical properties from dilative to contractive are associated with the increase of soil conditioning. The results are helpful to determine the conditioned soils and control ground deformation for real constructions.

[1]  P. Cundall,et al.  A discrete numerical model for granular assemblies , 1979 .

[2]  Hai-Sui Yu,et al.  Discrete element modelling of deep penetration in granular soils , 2006 .

[3]  Minna Karstunen,et al.  Micromechanical analysis of kinematic hardening in natural clay , 2009 .

[4]  Pierre-Yves Hicher,et al.  Micromechanical modelling for effect of inherent anisotropy on cyclic behaviour of sand , 2010 .

[5]  Mingjing Jiang,et al.  Analysis of stress redistribution in soil and earth pressure on tunnel lining using the discrete element method , 2012 .

[6]  Charles Wang Wai Ng,et al.  Centrifuge and numerical investigation of passive failure of tunnel face in sand , 2012 .

[7]  Zhen-Yu Yin,et al.  Stress–dilatancy behavior for sand under loading and unloading conditions , 2013 .

[8]  P B Attewell,et al.  PREDICTING THE DYNAMICS OF GROUND SETTLEMENT AND ITS DERIVITIVES CAUSED BY TUNNELLING IN SOIL , 1982 .

[9]  Hai-Sui Yu,et al.  A novel discrete model for granular material incorporating rolling resistance , 2005 .

[10]  O. Kusakabe,et al.  Shield Tunnel Construction in Centrifuge , 1999 .

[11]  Serge Leroueil,et al.  A simple and efficient approach to capturing bonding effect in naturally microstructured sands by discrete element method , 2007 .

[12]  Luis Medina Rodríguez,et al.  Discrete Numerical Model for Analysis of Earth Pressure Balance Tunnel Excavation , 2005 .

[13]  Mingjing Jiang,et al.  Classical and non-classical kinematic fields of two-dimensional penetration tests on granular ground by discrete element method analyses , 2008 .

[14]  Robert J. Mair,et al.  Observations of ground and structure movements for compensation grouting during tunnel construction at Waterloo station , 1994 .

[15]  Jiro Takemura,et al.  OBSERVED BEHAVIOUR OF A TUNNEL IN SAND SUBJECTED TO SHEAR DEFORMATION IN A CENTRIFUGE , 2010 .

[16]  Mohamed A. Meguid,et al.  Physical modeling of tunnels in soft ground: A review , 2008 .

[17]  Hehua Zhu,et al.  Laboratory model tests and field investigations of EPB shield machine tunnelling in soft ground in Shanghai , 2011 .

[18]  Hehua Zhu,et al.  Modeling shear behavior and strain localization in cemented sands by two-dimensional distinct element method analyses , 2011 .

[19]  Yangjun Chen,et al.  Face stability analysis of shallow shield tunnels in dry sandy ground using the discrete element method , 2011 .

[20]  Hehua Zhu,et al.  Two-Dimensional Discrete Element Theory for Rough Particles , 2009 .

[21]  Serge Leroueil,et al.  An efficient technique for generating homogeneous specimens for DEM studies , 2003 .

[22]  Nick Barton,et al.  Back-analysis of Shimizu Tunnel No. 3 by distinct element modeling , 2007 .

[23]  Pierre-Yves Hicher,et al.  Multiscale modeling of a sensitive marine clay , 2011 .

[24]  Serge Leroueil,et al.  Insight into shear strength functions of unsaturated granulates by DEM analyses , 2004 .

[25]  Daniele Peila,et al.  Using the Slump Test to Assess the Behavior of Conditioned Soil for EPB Tunneling , 2009 .