Three-dimensional numerical simulation of a mechanized twin tunnels in soft ground

Anh, Ngoc; Dias, Daniel; Oreste, Pierpaolo; Djéran-Maigre, Irini

doi:10.1016/j.tust.2014.02.001

Cited by 176 publications

(95 citation statements)

References 27 publications

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“…The twin horizontal tunnels, separated by a distance of 15 m between the two tunnel centers, each has an external excavation diameter of 9.4 m and an internal diameter of 8.3 m. The two tunnels were excavated at a depth of between 15 m and 25 m below the ground surface, through alluvial deposits of the late Pleistocene-Pliocene era, mostly from the Savena River, and deposits of clay and sandy soil (clayey sands and Pliocene clay). Some typical parameters of the ring 582 section were adopted in this study (Do et al, 2014a;2014b).…”

Section: Three-dimensional Numerical Modelmentioning

confidence: 99%

“…Stiffness is adopted as a function of the effective confinement, which leads to a higher value for unloading-reloading stiffness. Parameters of the soil are presented in Table 1. The numerical model, the 3D simulation procedure for a mechanized tunnel, and the parameter calibration of the CYsoil model are described by Do et al (2014a;2014b;2014d). Therefore, only a short overview is given here.…”

Section: Three-dimensional Numerical Modelmentioning

confidence: 99%

“…The tunnel lining parameters are presented in Table 2. The stiffness parameters of the joint connection were taken into consideration by means of a set composed of a rotational spring (K  ), an axial spring (K A ), and a radial spring (K R ) (Do et al, 2013;2014a;2014b;2014c). Similarly, the rigidity characteristics of the ring joint connection were represented by a set A total weight of 3980 kN was simulated for the back-up train through the vertical loads, which act on the lining elements in the bottom region of the tunnel over an assumed angle of 90° in the cross-section and over a tunnel length of 72 m behind the shield tail (Kasper and Meschke, 2004).…”

Section: Three-dimensional Numerical Modelmentioning

confidence: 99%

“…As far as the excavation of mechanized twin tunnels in close proximity is concerned, most cases reported in previous studies have focused on the interactions between two horizontally driven tunnels, using physical tests (Kim, 1996;Chapman et al, 2007;Choi and Lee, 2010;He et al, 2012;Ng et al, 2013;Ng, 2014;Ng and Lu, 2014), field measurements (Yamaguchi et al, 1998;Suwansawat and Einstein, 2007;Chen et al, 2011;Zhou et al, 2012;Ocak, 2013), empirical/analytical methods (Wang et al, 2003;Hunt, 2005;Suwansawat and Einstein, 2007;Yang and Wang, 2011), and numerical analyses (Yamaguchi et al, 1998;Hefny et al, 2004;Zheng and Qiu, 2005;Karakus et al, 2007;Hage Chehade and Shahrour, 2008;Afifipour et al, 2011;Chakeri et al, 2011;Ercelebi et al, 2011;Mahmutoğlu, 2011;Channabasavaraj and Vishwanath, 2012;Hasanpour et al, 2012;Li et al, 2012;Do et al, 2014b;2014d). However, less work has been devoted to the interactions between tunnels stacked over each other (Yamaguchi et al, 1998;Hefny et al, 2004;Suwansawat and Einstein, 2007;Hage Chehade and Shahrour, 2008;Liu et al, 2008;Channabasavaraj and Vishwanath, 2012;…”

Section: Introductionmentioning

confidence: 99%

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Three-dimensional numerical simulation of mechanized twin stacked tunnels in soft ground

Anh

Dias

Oreste

2014

J. Zhejiang Univ. Sci. A

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Abstract:The increase in transportation in large cities has made it necessary to construct twin tunnels at shallow depths. As far as the parallel excavation of mechanized twin tunnels is concerned, most of the cases reported in previous studies have focused on the interactions between two horizontally driven tunnels. However, less work has been devoted to the interactions between tunnels stacked over each other. The numerical investigation performed in this study has made it possible to evaluate the influence of the construction process on two stacked tunnels, using the FLAC 3D finite difference element software. The structural forces induced in each of the stacked tunnels and the displacements in the surrounding ground have been highlighted. The results of the numerical analysis indicate that new tunnel construction can have a great impact on an existing tunnel. The greatest impacts are observed when the upper tunnel is excavated first. The excavation of the upper tunnel generally leads to greater surface settlements than when the lower tunnel is excavated first. This study also shows that the normal forces induced in the lower tunnel are always greater than those developed in the upper tunnel. The normal displacements and the bending moments induced in the lower tunnel are usually smaller than those in the upper tunnel.

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Section: Three-dimensional Numerical Modelmentioning

confidence: 99%

Section: Three-dimensional Numerical Modelmentioning

confidence: 99%

Section: Three-dimensional Numerical Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Three-dimensional numerical simulation of mechanized twin stacked tunnels in soft ground

Anh

Dias

Oreste

2014

J. Zhejiang Univ. Sci. A

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“…A thorough analysis of the interaction between a tunnel excavated by shielded TBM and segmental lining can be developed with the numerical modeling, preferably of three-dimensional type (Do et al, 2014a;2014b). This modeling turns out to be quite complex and computation times are typically high.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the Interaction between the Lining of a TBM Tunnel and the Ground Using the Convergence-Confinement Method

Oreste¹

2015

American Journal of Applied Sciences

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Abstract:The support used when a tunnel is excavated by a shielded TBM is complex because it consists of two different materials: A concrete segmental lining and a filler annulus between the lining and the tunnel wall. A detailed analysis of the behavior of such a support system requires a three-dimensional numerical modeling and should also consider the presence of the TBM machine. This article presents an analytical calculation procedure that allows to assess the interaction between the support system and the tunnel using the convergence-confinement method and Vlachopoulos-Diederichs method. Furthermore, it is defined the overall stiffness of the support system starting from the detailed analysis of the stresses and strains developed in the two constituent materials. From the analysis of the evolution of the radial displacements in the longitudinal section, it was then possible to evaluate another fundamental parameter: The radial displacement of the tunnel wall at the point of installation of the support system. The computational procedure was then applied to a specific case, showing the influence of the stiffness of the filling material on the final loads acting on the segmental lining.

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Case study of performance assessment of overlapping shield tunnels with a small curve radius

Zhang,

Luo,

et al. 2023

Deep Underground Science and Engineering

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Due to the network planning of subways and their surrounding structures, increasingly more overlapping shields with a small curve radius have been constructed. A newly constructed upper tunnel partly overlaps a lower one, leading to the extremely complex uplift of the lower tunnel caused by the construction of a new tunnel. Based on the shield‐driven project that runs from the Qinghe Xiaoyingqiao Station to the Qinghe Station in Beijing, which adopts the reinforcement measures of interlayer soil grouting and steel supports on site, in this study, the uplift pattern of the lower tunnel and the stress characteristics of steel supports were investigated through numerical simulations and on‐site monitoring. The study results show that among all tunnel segments, the first segment of the shield witnesses a maximum uplift displacement that increases with the horizontal space between tunnels. On using either interlayer soil grouting or steel‐ring bracing reinforcement, the uplift of the tunnel lining exceeds the control value; by contrast, when these two measures are jointly applied, the uplift of the tunnel lining does not exceed a maximum value of 4.87 mm, which can satisfy the requirements of deformation control. Under these two joint measures, the soil strength between two stacked shield tunnels can be enhanced and the uplift deformation can be restricted with the interlayer soil grouting. Also, the segmental deformation and overall stability of the existing tunnel can be controlled with the temporary steel supports. The deformation of circumferential supports and segments is closely related to each other, and the segmental uplift is controlled by H‐shaped steel supports. With the increase in the horizontal space between twin shields, the effect of the construction would gradually weaken, accompanied by a gradual reduction of the stresses of steel supports. These findings provide a valuable reference for the engineering design and safe construction of overlapping shield tunnels with a small curve radius.

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Three-dimensional numerical simulation of a mechanized twin tunnels in soft ground

Cited by 176 publications

References 27 publications

Three-dimensional numerical simulation of mechanized twin stacked tunnels in soft ground

Three-dimensional numerical simulation of mechanized twin stacked tunnels in soft ground

Analysis of the Interaction between the Lining of a TBM Tunnel and the Ground Using the Convergence-Confinement Method

Case study of performance assessment of overlapping shield tunnels with a small curve radius

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