scholarly journals Research on the Optimal Clearance Distance of Super-Large-Diameter Shield Tunnel Underpassing the Existing Metro Tunnel

2021 ◽  
Vol 783 (1) ◽  
pp. 012002
Author(s):  
Nian Liu
Keyword(s):  
Large Diameter ◽  
Shield Tunnel ◽  
Metro Tunnel

Numerical Analysis of Metro Station Construction by Large-Diameter Shield and Pile-Beam-Arch Method

2011 ◽  
Vol 368-373 ◽  
pp. 2711-2715 ◽  
Author(s):  
De Yun Ding ◽  
Xiu Ren Yang ◽  
Wei Dong Lu ◽  
Wei Ning Liu ◽  
Mei Yan ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Large Diameter ◽  
Element Model ◽  
Construction Method ◽  
Shield Tunnel ◽  
Outer Diameter ◽  
Shield Tunneling ◽  
Metro Station ◽  
Dimensional Finite Element ◽  
New Construction

In more and more complicated urban building environment, a new construction method that metro engineering is constructed by large-diameter shield and shallow mining method can be regarded as a great attempt in China. By taking the Gaojiayuan station of Beijing metro line 14 as an engineering background, the main construction steps for the platform of the metro station built by a large-size shield with an outer diameter of 10 m and the Pile-Beam-Arch (PBA) method are introduced. Based on the soil-structure interaction theory, a two-dimensional finite element model is used to simulate the shield tunneling and the platform construction by the PBA method to enlarge the shield tunnel. The ground deformation and structural stress of the platform are predicted. The numerical results can be regarded as a valuable reference for the application of the new construction method in Beijing metro line 14.

scholarly journals Analysis of Influence on the Super-Large-Diameter Shield Tunnel by Stockpile Unloading

2021 ◽  
Vol 791 (1) ◽  
pp. 012028
Author(s):  
Sheng Wang ◽  
Guangming You ◽  
Nian Liu ◽  
Yazhou Zhang ◽  
Chunlong Yu
Keyword(s):  
Large Diameter ◽  
Shield Tunnel

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.

Analysis on Segment Floating in the Construction of Large-Diameter Crossing-River Shield Tunnel

2015 ◽  
Vol 724 ◽  
pp. 17-21
Author(s):  
Run Lai Zhang ◽  
Li Ming Tang ◽  
Kun Tang
Keyword(s):  
Frictional Force ◽  
Large Diameter ◽  
Shield Tunnel ◽  
Shield Tunneling ◽  
Factors Affecting ◽  
Grouting Pressure ◽  
Rapid Setting ◽  
Grouting Material ◽  
Longitudinal Stiffness ◽  
Initial Solidification

Segment floating is a common problem met in the construction of large-diameter crossing-river shield tunnel. The factors affecting segment floating are discussed first and analyzed by numerical simulation, including the properties of grouting material, the speed of shield tunneling, grouting pressure difference, the tunnel longitudinal stiffness, frictional force between segment rings and weight of the supporting system. The simulation results indicate that segment floating will reduce by shortening slurry’s initial solidification time, slowing shielding speed, improving the tunnel longitudinal stiffness as well as increasing the frictional force between segment rings. And some measures are given such as applying new rapid-setting slurries, shear pins, rubber mats with high friction coefficient and pre-stressed bolts

scholarly journals Structural Monitoring of Metro Infrastructure during Shield Tunneling Construction

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
L. Ran ◽  
X. W. Ye ◽  
G. Ming ◽  
X. B. Dong
Keyword(s):  
Ground Surface ◽  
Structural Monitoring ◽  
Shield Tunnel ◽  
Shield Tunneling ◽  
Construction Monitoring ◽  
Infrastructure Monitoring ◽  
Ground Freezing ◽  
Artificial Ground Freezing ◽  
Metro Tunnel ◽  
General Architecture

Shield tunneling construction of metro infrastructure will continuously disturb the soils. The ground surface will be subjected to uplift or subsidence due to the deep excavation and the extrusion and consolidation of the soils. Implementation of the simultaneous monitoring with the shield tunnel construction will provide an effective reference in controlling the shield driving, while how to design and implement a safe, economic, and effective structural monitoring system for metro infrastructure is of great importance and necessity. This paper presents the general architecture of the shield construction of metro tunnels as well as the procedure of the artificial ground freezing construction of the metro-tunnel cross-passages. The design principles for metro infrastructure monitoring of the shield tunnel intervals in the Hangzhou Metro Line 1 are introduced. The detailed monitoring items and the specified alarming indices for construction monitoring of the shield tunneling are addressed, and the measured settlement variations at different monitoring locations are also presented.

Study on the Influence of the Shield Tunnel Deformation Due to Excavation of Foundation Pit with Field Data

2012 ◽  
Vol 446-449 ◽  
pp. 1808-1812
Author(s):  
Jiang Shu Ding ◽  
Yao Qiang Xian ◽  
Tian Jun Liu
Keyword(s):  
Stress State ◽  
Field Data ◽  
Influence Factors ◽  
Shield Tunnel ◽  
Deep Excavation ◽  
Foundation Pit ◽  
Metro Tunnel ◽  
Main Influence

The deep excavation of the foundation pit adjacent to the metro tunnel will change the stress state of the neighboring soil. And the deformation of tunnel will be induced which will cause impair to daily operation and the safety of metro tunnel. According to the practice of deep excavation neighboring the metro tunnel in Guangzhou, the main influence factors of deformation and stress of tunnel will be analyzed based on exaction conditions and field data. The conclusions will be benefit to similar projects.

Comparative Analysis of Schemes for Metro Station Built by Enlarging Large-Diameter Shield Tunnel

2011 ◽  
Vol 368-373 ◽  
pp. 2731-2735 ◽  
Author(s):  
Mei Yan ◽  
Xiu Ren Yang ◽  
Ai Min Li ◽  
Wen Jun Wang ◽  
De Yun Ding
Keyword(s):  
Architectural Design ◽  
Large Diameter ◽  
Mass Transit ◽  
Construction Method ◽  
Shield Tunnel ◽  
Metro Station ◽  
Building Conditions ◽  
Advantages And Disadvantages ◽  
New Construction ◽  
Building Environment

With the speedy development of Beijing mass transit, the land for metro engineering construction is becoming more and more insufficient; moreover, more and more complicated building environment problems are coming forth in future. In a complex building environment, how to choose available construction method to fast, safely and economically build metro engineering is worthy to be urgently studied in Beijing mass transit. Taking the experiment project of Beijing metro line No.14 as an engineering background, a new construction method that a running tunnel is firstly built by large-size shield method and then a metro station is constructed by shallow mining method to enlarge existing large-diameter shield tunnel is presented in this paper. Based on the building conditions of the experiment project, three architectural design schemes for the metro station and two kinds of construction plans are briefly introduced, and their advantages and disadvantages are analyzed as well. The new construction method can be used as a reference for the design and construction of metro engineering in China in the future.

Improved Model of Metro Segment Liner Endogenetic Forces

2013 ◽  
Vol 438-439 ◽  
pp. 1028-1031
Author(s):  
Yue Yang ◽  
Xiao Guo Chen
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structure ◽  
Research Result ◽  
Shield Tunnel ◽  
Reinforced Concrete Structure ◽  
New Model ◽  
Metro Tunnel ◽  
Improved Model ◽  
Design And Construction

Harbin metro, the first engineering is in the process of being built. Metro tunnel is supported by reinforced concrete structure. Commonly used model is used in design of shield tunnel liner. In this paper, the habitual model is improved. The joint of model of the habitual model is improved and the endogenetic force formulas for the new model are derived. At last, the derived formulas and the existing formulas are validated by Harbin first metro. According to the research result, we can know the formulas derived in the paper are credible and they have academic practical meaning for design and construction of the subway liner.

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