The research on longitudinal deformation features of shield tunnel when considering the variation of grout viscosity: A case study

2019 ◽  
pp. 2473-2481
Author(s):  
Y. Liang ◽  
L.C. Huang ◽  
J.J. Ma
Keyword(s):  
Shield Tunnel ◽  
Longitudinal Deformation ◽  
Deformation Features

Key Construction Technologies for Large River-Crossing Slurry Shield Tunnel: Case Study

2021 ◽  
Vol 34 (2) ◽  
pp. 04020118
Author(s):  
Song Zhou ◽  
Guan-Lin Ye ◽  
Lei Han ◽  
Wang Jian-Hua
Keyword(s):  
Large River ◽  
Shield Tunnel ◽  
Slurry Shield

Soil-water inrush induced shield tunnel lining damage and its stabilization: A case study

2020 ◽  
Vol 97 ◽  
pp. 103290 ◽  
Author(s):  
Linchong Huang ◽  
Jianjun Ma ◽  
Mingfeng Lei ◽  
Linghui Liu ◽  
Yuexiang Lin ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Inrush ◽  
Tunnel Lining ◽  
Shield Tunnel

scholarly journals Experimental Study on the Transverse Effective Bending Rigidity of Segmental Lining Structures

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Yong-feng Tang ◽  
Han-cheng Chen ◽  
Zhen-wei Ye ◽  
Ting-jin Liu ◽  
Yu-bing Yang
Keyword(s):  
Regression Equation ◽  
Shield Tunnel ◽  
Outer Diameter ◽  
Test Results ◽  
Bending Rigidity ◽  
Segmental Lining ◽  
Ring Model ◽  
Scale Models ◽  
Elastic Stage

The transverse effective rigidity ratio is a key parameter when the uniform rigidity ring model is adopted to design or numerically analyse segmental lining structures commonly used on a shield-driven tunnel. Traditionally, the transverse effective rigidity ratio η is treated as a constant, which can be evaluated through theoretical analysis and model tests. In this study, scale models were designed and tested to investigate the variation of the transverse effective rigidity ratio in the segmental linings’ flattening deformation process. The test results suggested that in the elastic stage, the transverse effective rigidity ratio fluctuated between 0.667 and 0.734 for the stagger-jointed rings and fluctuated between 0.503 and 0.642 for the straight-jointed rings. When segmental linings were squashed and started to crack at the circumferential joints, the transverse effective rigidity ratio decreases sharply. Then, a regression equation was obtained to fit the variation trend of η with the increase of horizontal convergence to the outer-diameter ratio (ΔD/Dout). Finally, in a case study, the regression equation was adapted to determine the value of η of an operated shield tunnel which was once surcharged accidentally and deformed severely so as to numerically predict the prospective deformation induced by the upcoming adjacent excavation. Numerical results indicated that as the value of η decreases, the horizontal convergences of shield tunnel induced by adjacent excavation increase significantly and even more than doubled in the case study. Comparatively, through taking account of the operating tunnels’ exiting transverse deformation, the predicted deformation tends to be unfavourable.

Differential settlement remediation for new shield metro tunnel in soft soils using corrective grouting method: case study

2018 ◽  
Vol 55 (12) ◽  
pp. 1877-1887 ◽  
Author(s):  
Shunhua Zhou ◽  
Junhua Xiao ◽  
Honggui Di ◽  
Yaohong Zhu
Keyword(s):  
Yangtze River Delta ◽  
Differential Settlement ◽  
Shield Tunnel ◽  
Soft Soils ◽  
Average Value ◽  
Acceptable Deviation ◽  
Metro Tunnel ◽  
The Yangtze River Delta ◽  
Metro System

In the Yangtze River Delta of China, a large number of metro tunnels have been constructed in soft soils. The excessive and differential tunnel settlement may impair the serviceability of the metro system. The treatment of such excessive and differential settlement in rheologic and sensitive soft soils is a challenge because the tunnel may incur a larger settlement due to construction disturbances. In this paper, a case study of the differential settlement treatment of the new shield tunnel of Ningbo Metro line 2 is presented. A maximum tunnel settlement of 214 mm was observed several months after construction of the tunnel was completed. To uplift the deviated tunnel axis, a grouting and lifting measure named “bottom grouting, inner support, real-time monitoring and immediate adjusting” is proposed. The settlement treatment section is successfully uplifted with an average value of 30 mm, and the maximum final uplift amount of the tunnel is 41 mm, which reached the target value of uplift. The maximum convergence deformation caused by the grouting is 10 mm, which is less than the maximum acceptable deviation, i.e., 15.5 mm. The corrective grouting method and the valuable monitoring data presented in this study can provide a reference for projects with similar problems in the future.

scholarly journals Shield Equipment Optimization and Construction Control Technology in Water-Rich and Sandy Cobble Stratum: A Case Study of the First Yellow River Metro Tunnel Undercrossing

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Fei Ye ◽  
Nan Qin ◽  
Xiang Gao ◽  
Xue-yong Quan ◽  
Xian-zhuo Qin ◽  
...  
Keyword(s):  
Large Scale ◽  
Yellow River ◽  
Shield Tunnel ◽  
The Yellow River ◽  
Protective Device ◽  
Aperture Ratio ◽  
Metro Tunnel ◽  
Sand Pits ◽  
Cutter Head

The Lanzhou Yellow River Tunnel is the first metro shield tunnel that undercrosses the Yellow River in China. It was completed after successfully overcoming several construction challenges, including strata with a high proportion of large-sized sandy cobble stratum being saturated, large-scale sand pits along the bank of the Yellow River, and a combination of boulders and erratic blocks of rock. Given the difficulties in constructing the tunnel, this paper summarizes the scheme employed to transform the cutter and cutter head design to be applicable to sandy cobble stratum and the key technology used to form the slurry film to facilitate crossing the sand pits in a systematic way. The transformation scheme primarily involved the addition of an adjusting device to control the aperture ratio of the shield on the cutter head, a protective device for the hob hub, and a protective device for the piston rod in the oil cylinder of the crusher. The implementation of measures mentioned above guarantees the safe completion of the tunnel, which can provide a reference for similar projects.

Back Analysis of Water and Earth Loads on Shield Tunnel and Structure Ultimate Limit State Assessment: A Case Study

2018 ◽  
Vol 44 (5) ◽  
pp. 4839-4853 ◽  
Author(s):  
Qixiang Yan ◽  
Weilie Zhang ◽  
Chuan Zhang ◽  
Hang Chen ◽  
Yongwen Dai ◽  
...  
Keyword(s):  
Limit State ◽  
Back Analysis ◽  
State Assessment ◽  
Shield Tunnel ◽  
Ultimate Limit State ◽  
Ultimate Limit

scholarly journals Spatiotemporal Deformation of Existing Pipeline Due to New Shield Tunnelling Parallel Beneath Considering Construction Process

2022 ◽  
Vol 12 (1) ◽  
pp. 500
Author(s):  
Xiang Liu ◽  
Annan Jiang ◽  
Qian Fang ◽  
Yousheng Wan ◽  
Jianye Li ◽  
...  
Keyword(s):  
Shield Tunnel ◽  
Support Pressure ◽  
Construction Process ◽  
Longitudinal Deformation ◽  
Deformation Control ◽  
Spatiotemporal Characteristic ◽  
Shield Tunnelling ◽  
Grouting Reinforcement ◽  
Ground Volume Loss ◽  
Parametric Analyses

In this paper, we study the effects of the shield tunnel construction on the deformation of an existing pipeline parallel to and above the new shield tunnel. We propose an analytical solution to predict the spatiotemporal deformation of the existing pipeline and consider different force patterns of the shield tunnelling, i.e., ground volume loss, support pressure, frictional force, and torsional force. The proposed method is validated by the monitoring data of Subway Line 3 of Nanchang and provides a reasonable estimation of the pipeline’s deformation. The parametric analyses are performed to study the influences on the pipeline’s deformation. The main advantage of our paper is that the spatiotemporal characteristics of the existing pipeline’s deformation are analysed, providing longitudinal deformation curve (LDC), deformation development curve (DDC), and grouting reinforcement curve (GRC). Compared with the perpendicular undercrossing project, both LDC and DDC have the same profiles and maximum values and move forward as a whole with the shield tunnel advance. Thus, the spatiotemporal deformation of the overall pipeline can be extrapolated from the deformation of two known points on the pipeline. The spatiotemporal characteristic curves combined with LDC, DDC, and GRC can suggest feasible, effective, and economical construction and grouting schemes to control the pipeline’s deformation after the deformation control standards have been determined.

The impact of uneven temperature distribution on stability of concrete structures using data analysis and numerical approach

2020 ◽  
pp. 136943322095061
Author(s):  
Xuyan Tan ◽  
Weizhong Chen ◽  
Luyu Wang ◽  
Jianping Yang
Keyword(s):  
Temperature Distribution ◽  
Tensile Stress ◽  
Statistical Model ◽  
Temperature Variation ◽  
Concrete Structure ◽  
Shield Tunnel ◽  
Structure Stability ◽  
Mechanical Behaviors ◽  
Analytical Results

Temperature variation is an essential factor to influence the stability of concrete structure. In contrast to the uniform distribution of temperature in most existing approaches, this paper aims to study the natural temperature distribution in concrete structure and analyze its impact on structural mechanical behaviors in field. As a case study, an underwater shield tunnel is investigated using the presented method. Firstly, temperature sensors are installed in different positions to achieve real-time monitoring in field. Then, a statistical model is derived by monitoring data to describe temperature variation. As a core component of the approach, the devised statistical model is integrated into our program to determine the external loads imposed on model. Finally, the mechanical behaviors of concrete structure are discussed under uneven temperature distribution. Analytical results indicated the magnitudes of temperature distribution is related to different positions of structure, in which the significant distinctions can be observed at upper and lower of tunnel as well as the inside and outside structures. Also, the tensile stress of tunnel lining increases with the rise of temperature, for instance, in this case study per temperature rising would lead to an increment 25.3 KPa of tensile stress. As a promising application, the analytical results provide an assessment of concrete structure stability.

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