scholarly journals The Effects of Tangential Ground–Lining Interaction on Segmental Lining Behavior Using the Beam-Spring Model

2020 ◽  
Vol 10 (3) ◽  
pp. 1084 ◽  
Author(s):  
Anh The Pham ◽  
Mitsutaka Sugimoto
Keyword(s):  
Urban Areas ◽  
Earth Pressure ◽  
Tangential Direction ◽  
Tunnel Lining ◽  
Parameter Study ◽  
Shield Tunneling ◽  
Segmental Lining ◽  
Load Models ◽  
Tunneling Method ◽  
Tunnel Lining Design

The shield tunneling method is widely used, especially in urban areas, since it is efficient for minimizing disturbances to surroundings. Although segmental lining is commonly used in this method, in both the research and practice of tunnel lining design, the interaction between the ground and lining in the tangential direction remains unclear; that is, the mobilizing shear stress due to load models and the degree of the bond in the tangential direction. Therefore, to clarify the effects and mechanism of the tangential ground–lining interaction on segmental lining behavior, a parameter study was carried out, taking tangential spring stiffness, load models, soil stiffness, and shallow and deep tunnels as parameters. The interaction conditions were based on the existing literature. It was found that (1) the tangential spring has small effects on lining behavior, (2) the load model significantly affects the sectional forces, (3) the initial tangential earth pressure and slip ground–lining boundary provide more safety from a design viewpoint, and (4) in the case of shallow tunnels in soft ground, tensile stress appears in the lining. Therefore, it is important to take the tangential ground–lining interaction conditions into consideration during tunnel lining analysis.

scholarly journals Study of the Construction Sequence of Overlapping Tunnels by the Shield Tunneling Method: A Case Study of the Longest Overlapping Tunnel in China

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Zhiyong Yang ◽  
Yaowen Ding ◽  
Yusheng Jiang ◽  
Kuanda Fang ◽  
Linwei Dong ◽  
...  
Keyword(s):  
Working Conditions ◽  
Radial Stress ◽  
Three Dimensional ◽  
Vertical Displacement ◽  
Tunnel Lining ◽  
Shield Tunneling ◽  
Construction Sequence ◽  
Tunneling Method ◽  
The Difference ◽  
Small Change

In this study, the reasonable construction sequence of an overlapping tunnel shield is investigated. Taking the overlapping tunnel of Tianjin Metro Line 5 as the background, a three-dimensional numerical model was established using Flac3D software to study the influence of the “first up and then down” and “first down and then up” construction sequences of the overlapping tunnel on the surface settlement, stratum displacement, lining radial stress, and displacement. The research results show that the shape and width of the final settlement tank on the ground under the two conditions are basically the same, and the difference between the maximum cumulative settlements is small. The accumulated ground settlement caused by the first up and then down construction sequence is 1.8 mm larger than that caused by the first down and then up sequence. The difference between the two working conditions on the vertical displacement of the stratum mainly occurs in the middle stratum of the upper and lower tunnels, and the proportion of the strata in the uplifted state and subsidence state is different. The construction sequence has little effect on the radial stress on the lining of the upper and lower tunnels. Under these two conditions, the excavation of the second tunnel causes a small change in the radial stress of the preceding tunnel lining, both within 4.2%. Under the working condition of first down and then up, the construction of the second tunnel causes the lining of the preceding tunnel to rise by 7.2∼9.2 mm. Under the condition of first up and then down, the construction of the second tunnel causes the lining of the preceding tunnel to sink again by 9.1∼10.4 mm. By comparing the effects of the two working conditions on the stratum and the tunnel lining, it is recommended that the construction be carried out in the order of first down and then up.

scholarly journals Experimental study on segmental lining in flat sectional shield tunneling method.

2003 ◽  
pp. 99-113
Author(s):  
Kazuyoshi TATEYAMA ◽  
Minoru KURAHASHI ◽  
Yingyongrattanakul NARENTORN ◽  
Takao YANO ◽  
Toshihisa ADACHI
Keyword(s):  
Experimental Study ◽  
Shield Tunneling ◽  
Segmental Lining ◽  
Tunneling Method

Preliminary Ideas of the Metro Station Constructed by Shield Tunneling Method Combined with Prefabricated Method

2014 ◽  
Vol 580-583 ◽  
pp. 1013-1018 ◽  
Author(s):  
Hui Feng Su ◽  
Wei Ning Liu ◽  
Fu Chun Liu
Keyword(s):  
The Other ◽  
Shield Tunnel ◽  
Spring Stiffness ◽  
Underground Engineering ◽  
Shield Tunneling ◽  
Metro Station ◽  
Key Technology ◽  
Tunneling Method ◽  
Assembly Technology ◽  
Northeast Of China

Confronting with the difficulties of the construction metro station in the Northeast of China, a new idea of shield method combined prefabricated method is put forward. In the paper the research status of the underground engineering precast assembly technology was analyzed and classified firstly. The method of single round interval shield combined with open-cut (or covered excavation) prefabricated sections and on the basis of shield tunnel to build single arch station is especially worth studying and promotion. Then the key prefabricate theory needing to deal with such as how to calculating the spring stiffness and so forth of the calculating model. The key technology such as joint formation, waterproof and the other of shield method combined with prefabricated method was discussed.

Compact shield tunneling method

2005 ◽  
Author(s):  
Setsuo Takaku ◽  
Masayuki Matsuura ◽  
Yasushi Nagashima ◽  
Yoichi Moriya
Keyword(s):  
Shield Tunneling ◽  
Tunneling Method

scholarly journals Nonlinear subgrade reaction solution for circular tunnel lining design based on mobilized strength of undrained clay

2018 ◽  
Vol 55 (2) ◽  
pp. 155-170 ◽  
Author(s):  
Dong-ming Zhang ◽  
Kok-Kwang Phoon ◽  
Qun-fang Hu ◽  
Hong-wei Huang
Keyword(s):  
Design Method ◽  
Large Strain ◽  
Tunnel Lining ◽  
Subgrade Reaction ◽  
Circular Tunnel ◽  
Nonlinear Solution ◽  
Reaction Solution ◽  
Tunnel Convergence ◽  
Tunnel Lining Design ◽  
Internal Forces

This paper presents a nonlinear solution of a radial subgrade reaction–displacement (pk–ur) curve for circular tunnel lining design in undrained clay. With the concept of soil shear strength nonlinearly mobilized with shear strain, an analytical solution of pk is obtained using the mobilized strength design method. Two typical deformation modes are considered, namely oval and uniform. A total of 197 orthogonally designed cases are used to calibrate the proposed nonlinear solution of pk using the finite element method with the hardening soil model. The calibration results are summarized using a correction factor, η, which is defined as the ratio of pk_FEM to pk_MSD. It is shown that η is correlated to some input parameters. If this correlation is removed by a regression equation, f, the modified solution f(pk_MSD) agrees very well with pk_FEM. Although in reality the mobilized soil strength varies with principal stress direction, it is found that a simple average of plane strain compression and extension results is sufficient to produce the above agreement. The proposed nonlinear pk–ur curve is applied to an actual tunnel lining design example. The predicted tunnel deformations agree very well with the measured data. In contrast, a linear pk model would produce an underestimation of tunnel convergence and internal forces by 2–4 times due to the overestimation of pk at a large strain level.

scholarly journals Approach for Optimisation of Tunnel Lining Design

2020 ◽  
Vol 10 (19) ◽  
pp. 6705
Author(s):  
Marek Mohyla ◽  
Karel Vojtasik ◽  
Eva Hrubesova ◽  
Martin Stolarik ◽  
Jan Nedoma ◽  
...  
Keyword(s):  
Rock Mass ◽  
Numerical Models ◽  
Tunnel Lining ◽  
Time Dependent ◽  
Design Element ◽  
Heterogeneous Structure ◽  
Underground Engineering ◽  
Software Application ◽  
Tunnel Lining Design ◽  
Dependent Property

This paper presents an approach that enables the specific characteristics of a primary tunnel lining implemented using numerical modelling to be taken into account during its design. According to the fundamental principles of the New Austrian Tunnelling Method, the primary lining undergoes time-dependent deformation, which is determined by its design. The main design element is shotcrete, which, shortly after its application, interacts with the surrounding rock mass and steel arch frame. The primary lining ensures the equilibrium stress–strain state of “rock mass–tunnel lining” during excavation. The structural interaction varies depending on the hardening of the shotcrete, the rheological properties of the rock mass, and other factors. The proposed approach uses the Homogenisation software application, which was developed by the Faculty of Civil Engineering at the Department of Geotechnics and Underground Engineering of the VSB—Technical University of Ostrava. This software allows the heterogeneous structure of the lining to be considered by replacing it with a homogenous structure. The parameters of the homogeneous primary lining, which take into account the steel reinforcement elements and the time-dependent property of the shotcrete, are included in numerical models.

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