Additive Load Influence Analysis of Shield Tunneling Construction on Adjacent Piles

2012 ◽  
Vol 193-194 ◽  
pp. 1033-1037
Author(s):  
Gang Wei ◽  
Jie Hong ◽  
Xin Jiang Wei
Keyword(s):  
Distribution Curve ◽  
Thrust Force ◽  
Pipe Wall ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Shield Tunnel ◽  
Dimensional Problem ◽  
Shield Tunneling ◽  
Tunnel Excavation ◽  
Shield Tunnelling

The distribution regular of total additive load induced by bulkhead additive thrust, force of friction between shield and soil, and soil loss during shield tunnelling construction was studied. The analytical results show that, the distribution regular of additive load is closely related with the relative position of pile and shield, and it is a three-dimensional problem. Toward the shield tunnelling direction and perpendicular to the pipe wall, the additive load is changed from press to pull force along with the pass of shield excavation face. In addition, the value and influence bound of additive load in shield tunnelling direction is bigger than that of perpendicular to the pipe wall. Value of additive load in vertical direction is small. Direction of additive load close to the axes of pipeline is opposite with that of both ends and the force distribution curve is arch-shaped. It is proved by the comparison with the results of numerical simulation, centrifuge experiments and field measurement that the study on the influence due to shield tunnel excavation on neighboring piles is reliable through analytical analysis.

Deformation Effect of Buried Pipeline in Shield Tunneling Crossing Thick and Hard Rock

2013 ◽  
Vol 639-640 ◽  
pp. 961-964
Author(s):  
Hong De Wang ◽  
Tie Jun Cui
Keyword(s):  
Hard Rock ◽  
Vertical Direction ◽  
Shield Tunnel ◽  
Buried Pipeline ◽  
Buried Pipelines ◽  
Shield Tunneling ◽  
Tunnel Excavation ◽  
Excavation Process ◽  
Deformation Modes ◽  
Stabilization Period

The shield tunneling construction would cause the buried pipeline deformation. In order to predict the influence to the buried pipeline when shield tunneling crossing the thick and hard strata, taking 201 contract section shield tunneling of Dalian Metro construction as the research object, the buried pipeline deformation effects are analyzed. Firstly, the shield tunnel excavation and support simulating model is constructed basing on Flac3D technique. Secondly, the ground settlement and its influence to the buried pipeline are analyzed with finite difference digital computation. According to the simulation for the shield tunneling crossing the thick and hard riverbed, the settling volume of the ground, the deformation modes and degrees of the buried pipelines are discussed to reveal the deformation rules. Results show that the deformations of two groups of measuring points tend to be uniform; the excavation process includes the stabilization period, the critical point and the deformation period in 50m long simulation model; the drainpipe appears deformation from three directions, and the severity of deformation mainly comes from the vertical direction settlement.

Numerical Simulation of Shield Tunnel Passing Through Underground Structure

2011 ◽  
Vol 105-107 ◽  
pp. 886-891
Author(s):  
Yong Suo Li ◽  
Ke Neng Zhang ◽  
Mei Long Deng ◽  
Chang Bo Huang
Keyword(s):  
Numerical Simulation ◽  
Underground Structure ◽  
Frame Structure ◽  
Shield Tunnel ◽  
Engineering Practice ◽  
Underground Engineering ◽  
Shield Tunneling ◽  
Tunnel Excavation ◽  
Mine Excavation ◽  
End Wall

Shield tunneling is often adopted in underground engineering such as civil tunnel construction and mine excavation. The program FLAC3D is used to simulate the process of the tunnel excavation through underground structure in Shenyang in this paper. The analysis results show that,(1) the soil below the end wall suffers great displacement, when the shield approaches the end wall of underground framework from different directions, so the soil under the end wall needs to be reinforced. (2) Increasing pressure and volume of grouting can’t significantly reduce the amount of surface subsidence when the drilling of the shield acrosses through the independent foundation. (3) The influences of shielding to the construction are limited because of the constraint function to the surrounding rock above the tunnel by the great entire rigidity of under-ground framework. The results of numerical simulation exactly matches the monitoring data when the stiffness of under-ground frame structure is considered, and it can provide guidance for engineering practice.

Numerical Study on the Effect of Twin-Tube Shield Excavation on Adjacent Pipelines

2012 ◽  
Vol 170-173 ◽  
pp. 1491-1496 ◽  
Author(s):  
Xin Wang ◽  
De Shen Zhao ◽  
Meng Lin Xu
Keyword(s):  
Distribution Curve ◽  
Numerical Study ◽  
Three Dimensional ◽  
Element Model ◽  
Stress Release ◽  
Tunnel Excavation ◽  
Normal Distribution Curve ◽  
Numerical Result ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Based on Dalian subway line 2 from Chun-guang street station to Xiang-gong street station,the three dimensional finite element model was established using FLAC3D software , the shield excavated surface against the pressure, the stress release, the shield tail escape and grouting. The numerical result indicated that the pipeline displacement increases gradually with the advance of the tunnel excavation. When one-sided tunnel excavation is carried out, the largest displacement is located at the tunnel axis, the settling curve basically conforms to the normal distribution curve with the unimodal characteristic. The excavation of right-side tunnel is disadvantageous to the left-side tunnel. The analysis indicated that the pipeline is in a secure state. The work in this paper provided theoretical basis and the practical guidance to this project.

scholarly journals Integration of Multiband InSAR and Leveling Measurements for Analyzing the Surface Subsidence of Shield Tunneling at Beijing-Zhangzhou High-Speed Railway

2021 ◽  
Vol 2021 ◽  
pp. 1-24
Author(s):  
Yueguan Yan ◽  
Qian Yang ◽  
Zhihui Jia ◽  
Xiaoyi Zhang ◽  
Huayang Dai ◽  
...  
Keyword(s):  
High Speed ◽  
Ground Surface ◽  
Synthetic Aperture ◽  
Shield Tunnel ◽  
Shield Tunneling ◽  
Modern Life ◽  
Tunnel Excavation ◽  
High Speed Railway ◽  
Synthetic Aperture Radar Interferometry ◽  
Surrounding Environment

In modern life, metro and high-speed rails have become indispensable transportation and have been playing an important role in many areas, especially in cities. The metro and high-speed rails have varying degrees of impact on the surface and surrounding buildings, which must be carefully understood to minimize the risk of hazards. This work is aimed at investigating the deformation of ground surface and the surrounding structures, caused by the excavation of underground tunnels. Because of the spatiotemporal characteristics of the land subsidence induced by underground tunnel construction, the measurements obtained from InSAR (Synthetic Aperture Radar Interferometry) and leveling techniques are integrated to study the subsidence phenomenon of the ground surface above the shield tunnels and the surrounding buildings. The subsidence-related parameters, including the advance angles, lag angles, and boundary angles, are derived from the deformation results. This study suggests that leveling and InSAR observations can provide technical support to study the subsidence of dense buildings on the surface of shield tunnel excavation and to protect the surrounding environment.

scholarly journals An Improved Method for Predicting the Greenfield Stratum Movements Caused by Shield Tunnel Construction

2019 ◽  
Vol 9 (21) ◽  
pp. 4522 ◽  
Author(s):  
Tan ◽  
Zhang ◽  
Zhang ◽  
Zhu ◽  
Tu
Keyword(s):  
Three Dimensional ◽  
Elastic Half Space ◽  
Shield Tunnel ◽  
Theoretical Formula ◽  
Tunnel Construction ◽  
Underground Structures ◽  
Underground Engineering ◽  
Shield Tunneling ◽  
Deep Soil ◽  
Contour Maps

Shield tunneling is becoming the preferred construction scheme for metro construction because of its advantages of fast construction speed and small disturbance. However, limited by process defects, the stratum movements induced by the construction of shield tunnels still affects the safety of nearby underground structures and aboveground buildings. Therefore, the reliable prediction of stratum movements is important. Described in this paper is an analysis method of the Greenfield stratum movements (Greenfield is an area of land that has not yet had buildings on it, stratum movements means the movement of various soil layers) caused by shield tunnel construction combining an elastic half-space model of mirror source–sink method with the use of modified analytical method. Based on the theoretical formula in this paper, not only can the curve of surface settlement trough be calculated, but also the three-dimensional displacement field of deep soil can be obtained. By comparing vertical and horizontal contour maps of Greenfield stratum movements, good consistency between theoretical formula results and centrifugal test results are shown. This solves the defects and limitations of existing two-dimensional formulas; furthermore, based on this, it is convenient to evaluate the effect on the other skewed underground structures through the elastic foundation beam and other similar methods; therefore, this paper can provide a wide guidance and service for the design and construction of underground engineering in the future.

Three Dimensional Numerical Analysis of Ground Settlement Induced by Shield Tunneling

2012 ◽  
Vol 182-183 ◽  
pp. 937-940
Author(s):  
Zhong Chang Wang
Keyword(s):  
Soil Layer ◽  
Three Dimensional ◽  
Ground Surface ◽  
Vertical Displacement ◽  
Ground Subsidence ◽  
Shield Tunnel ◽  
Ground Settlement ◽  
Shield Tunneling ◽  
Tunnel Face ◽  
Maximum Settlement

The fine numerical simulation is used to study the ground settlement of complex stratum owing to shield construction by ANSYS program. It is shown that the closer the distance between soil layer and the axis of tunnel is, the smaller the disturbance of construction is, the obvious the ground surface settlement is. The value of the maximum settlement at the center of the surface is 7.4mm. The maximum settlement of vault is 14mm. The ground subsidence in cross section distribution is shaped of normal distribution. The closer the distance between soil layer and ground surface is, the smaller the vertical displacement is, the bigger the width of settlement trough of soil layers is. The width of settlement trough is 25m. The volume loss rate of shield tunnel is about 0.32%. The width coefficient of ground settlement trough is 0.56. The tendency of ground settlement decrease to become gentle with the advance of shield construction. The ground settlement keeps constant after tunnel face advancing to 30m.

Effect of Shield Tunneling on High-Speed Railway Bridges under the Influence of Train Operations

2013 ◽  
Vol 831 ◽  
pp. 423-429
Author(s):  
Xiao Jing Wang ◽  
Kai Xu
Keyword(s):  
High Speed ◽  
Internal Force ◽  
Shield Tunnel ◽  
Railway Bridge ◽  
The Finite Element Method ◽  
Shield Tunneling ◽  
Tunnel Excavation ◽  
High Speed Railway ◽  
Railway Bridges ◽  
The Impact

This paper is based on one project of Metro shield tunnel across a high-speed railway bridge. In the study the impact of train operations is taken into account, the finite-element method is adopted to analyze effect of shield tunneling. The conclusions indicate that according to the different tunnels and relative positions of pile, the excavation of the tunnels would have different effects on pile foundation. When the construction of shield across the bridge, the nature of the soil and will have an effect on deformation and stress of pile. Due to tunnel excavation of bridge internal force on bridge attached to the forces of good roles and bad role. Additional deformation of the beams and the additional forces are very small, so they will not affect the bridge work.

Analysis on Influence of Shield Tunneling on Bridge Double Pile

2015 ◽  
Vol 777 ◽  
pp. 3-7
Author(s):  
Pei Sheng Xi ◽  
Xiao Zhao ◽  
Zhen Li
Keyword(s):  
Horizontal Displacement ◽  
Horizontal Direction ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Ground Settlement ◽  
Lagrangian Analysis ◽  
Shield Tunneling ◽  
Tunnel Excavation ◽  
Pile Deformation ◽  
Main Deformation

Shield tunneling have varying degrees of impact on the surrounding buildings and the surrounding environment. Based on the shield tunneling of Hefei Subway Line 1 Ma'anshan viaduct, a 3D Fast Lagrangian Analysis of Continua is be used to simulate the shield tunnel construction and analyze the ground settlement and bridge pile deformation caused by tunnel construction. The numerical modeling results by analyzing the displacement variation and soil affected area at different distances show that when the shield tunnel excavation, the ground settlement becomes smaller with increasing distance from the shield center line of the pile and the maximum ground settlement is 10.778mm. The main deformation of bridge pile is in horizontal direction with a maximum horizontal direction of 2.0758mm. Horizontal displacement changes lager at the top of the pile, along with changes in the horizontal displacement of the pile depth becomes smaller, 15m is a turning point.

Coupled Numerical Analysis of Tunnel Excavation in Saturated Soft Clay under High Groundwater

2011 ◽  
Vol 368-373 ◽  
pp. 2533-2536
Author(s):  
Hua Yuan ◽  
Hai Tao Wan ◽  
Zhi Liang Zhao
Keyword(s):  
Soft Clay ◽  
Three Dimensional ◽  
Bending Moment ◽  
High Water ◽  
Shield Tunnel ◽  
Deep Soil ◽  
Tunnel Excavation ◽  
Axial Forces ◽  
Reduction Effect ◽  
Saturated Soft Clay

A coupled numerical simulation of a river-crossing shield tunnel excavation in saturated soft clay with high groundwater has been performed using a three-dimensional finite difference model, which takes into account variation of soil permeability with stress, anisotropy of permeability, reduction effect of joints on segment bending stiffness and the hardening process of synchronized grouting material. Groundwater seepage conditions around the tunnel, bending moment, axial forces and strength safety factor of tunnel segment as well as deep soil displacement during tunnel diving are investigated numerically. The analyses provide valuable information concerning the mechanical behavior of tunnel segment and hydrological field in soil around tunnel during advancing. The result also is benefited to control groundwater for river-crossing tunnel in soft clay under high water table.

Study on Influencing Factor of Ground Deformation Induced by Shield Tunneling

2013 ◽  
Vol 734-737 ◽  
pp. 690-693
Author(s):  
Meng Lin Xu ◽  
De Shen Zhao
Keyword(s):  
Ground Deformation ◽  
Influencing Factor ◽  
Ground Movement ◽  
Shield Tunnel ◽  
Shield Tunneling ◽  
Tunnel Excavation ◽  
Security Issues ◽  
Surrounding Environment ◽  
Strata Deformation ◽  
Complex Construction

The complex construction behavior inevitably disturb surrounding environment, even when the tunneling goes through building, which may be wrecked. The security issues of the subway project stems from ground movement and structure dynamic interaction. So it is academic and application good value for study on construction influences of shield tunnel excavation to the neighboring buildings. This paper focuses on the shield tunnel construction strata deformation factors. The results provided the theory basis for safety construction.

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