Technical Measures of Shield Tunnel Construction in Alternating Hard and Soft Rock Strata

2014 ◽  
Author(s):  
Mingju Zhang ◽  
Huan He ◽  
Yi Liu
Keyword(s):  
Soft Rock ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Rock Strata ◽  
Technical Measures

scholarly journals A Novel Method for Analyzing the Factors Influencing Ground Settlement during Shield Tunnel Construction in Upper-Soft and Lower-Hard Fissured Rock Strata considering the Coupled Hydromechanical Properties

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Yan Wang ◽  
Yongjun Zhang ◽  
Zhen Zhu ◽  
Mingqing Du ◽  
Yi Qi
Keyword(s):  
Neural Network ◽  
Numerical Simulation ◽  
Elastic Moduli ◽  
Coarse Sand ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Ground Settlement ◽  
Factors Influencing ◽  
Fissured Rock ◽  
Rock Strata

Focusing on the special stratum conditions of upper-soft and lower-hard fissured rock strata, this paper conducts quantitative research and analysis on the factors influencing the ground settlement caused by shield tunnel construction considering the coupled hydromechanical properties and presents a corresponding numerical simulation-artificial neural network-Bayesian network- (NS-ANN-BN-) based method. In this method, with a subway shield tunnel as the engineering context, three numerical models are established, in which the shield tunnel is located in soft strata, the shield tunnel is located in semisoft and semihard strata, or the shield tunnel is located in hard strata. According to the numerical simulation (NS) calculations, the ground settlement values under the three types of strata are 38.96 mm, 10.42 mm, and 3.13 mm, respectively. A radial basis function artificial neural network (RBF-ANN) is used to establish the nonlinear mapping relationship between the stratum parameters and the ground settlement, and the training samples and test samples are generated through NS to train the RBF-ANN. After the training is completed, the accuracy of the neural network meets the requirements. The elastic moduli of coarse sand~gravel sand k3 and moderately weathered rhyolite k4 and the cohesion of moderately weathered rhyolite c4 are selected as the key parameters. A large number of training cases are generated through the RBF-ANN, and the Bayesian network (BN) prior probability is calculated by self-learning. A BN model of ground settlement for shield tunnel construction in the upper-soft and lower-hard fissured rock strata is established. The BN back analysis method is used to quantitatively analyze the influencing factors of the ground settlement. The results show that when the tunnel is located in soft strata, the surface settlement is mainly affected by parameter k3. When the ground settlement increases considerably, the three parameters all have a strong influence. When the tunnel is located in semisoft and semihard strata, the influence of the three parameters on the ground settlement is weak. When the tunnel is located in hard strata, the ground settlement is mainly affected by parameter k4. When the ground settlement greatly increases, parameters k3 and c4 have less influence. When the tunnel is located in strata with different soft-hard ratios, the ground settlement is mainly affected by the elastic moduli of coarse sand~gravel sand and moderately weathered rhyolite. This method can provide a reference for the ground settlement analysis of shield tunnel construction in areas with similar fissured rock strata.

The Major Problems and Countermeasures on the Shield Machine Tunneling in the Hard Rock Stratum

2011 ◽  
Vol 105-107 ◽  
pp. 1438-1442 ◽  
Author(s):  
Kai Rong Hong ◽  
Ren Hua Yang
Keyword(s):  
Hard Rock ◽  
Rapid Development ◽  
Soft Rock ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Construction Technology ◽  
Construction Costs ◽  
Shield Tunneling ◽  
Rock Stratum ◽  
Tunneling Method

With the rapid development of urban construction, the shield construction technology has been greatly developed. Shield tunneling method generally adapts to relatively uniform soil, soft rock and sand rock strata, and the shield tunnel construction has been more mature for the homogeneous strata. However, for the soft and hard interbedded strata, how to solve the problems of breaking the hard rock, increasing the tunneling efficiency and reducing the construction costs, are difficult problems in the shield tunnel construction. In this paper, based on a great deal of theoretical analyses and engineering practices, the effective methods of improving the efficiency of tunneling, reducing cutter wearing and decreasing the construction costs in the process of the shield tunneling construction in hard rock and gravel layer are proposed.

Impact of Double-O-Tube Shield Tunnel Construction on Grillage Beams Foundation Frame Building

2011 ◽  
Vol 71-78 ◽  
pp. 32-36 ◽  
Author(s):  
Xin Jiang Wei ◽  
Jie Hong ◽  
Gang Wei
Keyword(s):  
Principal Stress ◽  
Differential Settlement ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Foundation Settlement ◽  
Ground Settlement ◽  
Shield Tunneling ◽  
Frame Building ◽  
Shield Machine ◽  
The Impact

Considering the interaction of building-soil-tunnel, the grillage beams foundation frame building vertical crossed by Double-O-Tube (DOT) shield tunnel was simulated by 3D MIDAS/ GTS software, and the impact of construction on the building was analyzed. The results show that: the ground settlement trough caused by DOT shield tunnel can be fitted by peck formula; during the passage of the shield tunneling through the building, the settlement of the building increased and settlement trough was wilder; the settlement was stable and had a little rebound when shield machine already passed the building; with the increase of driving distance, the first principal stress P1 increased and then was stable; with the increase of L, the shape of foundation settlement curve changed, and the maximum differential settlement between columns increased but was small.

scholarly journals A Comprehensive Review of the Mechanical Behavior of Suspension Bridge Tunnel-Type Anchorage

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Yafeng Han ◽  
Xinrong Liu ◽  
Ning Wei ◽  
Dongliang Li ◽  
Zhiyun Deng ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Failure Modes ◽  
Load Transfer ◽  
Mechanical Response ◽  
Soft Rock ◽  
Suspension Bridge ◽  
Development Trend ◽  
Factors Affecting ◽  
Research Results ◽  
Rock Strata

The recent surge of interest towards the mechanical response of rock mass produced by tunnel-type anchorage (TTA) has generated a handful of theories and an array of empirical explorations on the topic. However, none of these have attempted to arrange the existing achievements in a systematic way. The present work puts forward an integrative framework laid out over three levels of explanation and practical approach, mechanical behavior, and calculation method of the ultimate pullout force to compare and integrate the existing findings in a meaningful way. First, it reviews the application of TTA in China and analyzes its future development trend. Then, it summarizes the research results of TTA in terms of load transfer characteristics, deformation characteristics, failure modes, and calculation of ultimate uplift resistance. Finally, it introduces four field model tests in soft rock (mainly mudstone formations), and some research results are obtained. Furthermore, it compares the mechanical behavior of TTA in hard rock strata and soft rock strata, highlighting the main factors affecting the stability of TTA in soft rock formation. This paper proposes a series of focused topics for future investigation that would allow deconstruction of the drivers and constraints of the development of TTA.

Surface Settlement and Influence on Xi’an City Wall due to Xi’an Subway Line 2 Tunnel Construction

2011 ◽  
Vol 374-377 ◽  
pp. 2326-2332
Author(s):  
Jun Lian Li ◽  
Jian Guo Zheng ◽  
Yang Ping Yao
Keyword(s):  
Surface Settlement ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
The South ◽  
Protective Measures ◽  
City Wall ◽  
Calculation Results ◽  
Settlement Ratio ◽  
Grouting Reinforcement ◽  
Xi’An City

This paper refers the case project of the Xi'an Subway Line 2 tunneling through the South Gate area of the Xi'an City Wall, has researched the surface settlement due to tunnel construction, and simulated the whole shield tunnel by using Flac3D numerical analysis. This paper has obtained the law of surface settlement and the influence on the City Wall in the tunnel construction by analyzing the calculation results, and simulated the effects of three protective measures which will be used in the South Gate area. The results showed that the surface settlement ratio after the piles and chemical grouting reinforcement was lower by about 25% than no reinforcement. The monitoring data showed that the result of model calculation was reasonable, and the protective measures in Condition 3 are feasible and effective.

Analysis on the Mechanical Behavior of Pipe Roof and Rock Bolt of Shallow and Unsymmetrical Tunnel in Soft Rock

2012 ◽  
Vol 443-444 ◽  
pp. 267-271
Author(s):  
Xu Dong Cheng ◽  
Peng Ju Qin
Keyword(s):  
Soft Rock ◽  
Surrounding Rock ◽  
Mechanical Behaviors ◽  
Maximum Displacement ◽  
Tunnel Excavation ◽  
Finite Element Software ◽  
Highway Tunnel ◽  
Geological Conditions ◽  
The Impact ◽  
Rock Strata

In this paper, the mechanical behaviors of pipe roof and bolt of shallow and unsymmetrical tunnel in soft rock are analyzed. Through the finite element software Phase2.0, combined with the geological conditions that construction site often appear, the mechanical behaviors of pipe roof and bolt and surrounding rock in the process of horseshoe highway tunnel construction in the condition that surface is soft rock and underground for the bedrock are analyzed. Research results show that: after tunnel excavation in soft rock, surrounding rock near the tunnel is easy to suffer soft-rock large deformation even failure, which needs to timely support；Due to the impact of the unsymmetrical tunnel, the mechanical behaviors of surrounding rock are unsymmetrical, such as the maximum displacement of tunnel around 0.4 m distant from apex of arch ring, the stress is asymmetrical on both sides of the tunnel arch ring etc; In addition, pipe roof can effectively prevent from the displacement of soft rock strata, improve tunnel strength factor, reduce the plastic zone of surrounding rock. This paper provides theoretical basis for the design of pipe roof and bolt.

Analysis of Soil Disturbance by Shield Tunneling

2013 ◽  
Vol 734-737 ◽  
pp. 502-506
Author(s):  
Meng Lin Xu ◽  
De Shen Zhao
Keyword(s):  
Numerical Simulation ◽  
Soil Disturbance ◽  
Technical Support ◽  
Surface Subsidence ◽  
Stress Redistribution ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Soil Deformation ◽  
Shield Tunneling ◽  
Induced Stress

The shield tunneling will be bound to disturb surrounding strata, induced stress redistribution in soil, soil deformation and surface subsidence. We analyzed characteristics of soil disturbance by shield tunneling with numerical simulation. To provide technical support for the future urban shield tunnel construction. It shows practically significant in studying shield tunnel construction.

Experiment of Slurry Shield Tunnel Recycling Waste Sand in Sand-Pebble Layer

2014 ◽  
Vol 919-921 ◽  
pp. 1104-1109
Author(s):  
Chen Rui Pang ◽  
Xin Wen
Keyword(s):  
Fine Sand ◽  
The Other ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Sand Layer ◽  
Large Space ◽  
City Environment ◽  
Slurry Shield ◽  
Sand Source ◽  
Waste Soil

Waste soil progressing in shield tunnel construction should occupy large space, on the other hand, do harm to city environment. If the waste sand in silt and fine sand layer can be used as sand source of synchronous grouting, it will bring benefits for the enterprise and society. In indoor experiment, we select waste sand in different layers, sieved as sand source, then use the waste sand to produce slurry and compare their strength with the construction slurry’s. The study found, sieved waste sand in silt and fine sand layer can be used as sand source for making synchronous grouting slurry.

Interaction Function Analysis between Shield Tunnel Construction and Single Pile

Logistics ◽  
2009 ◽  
Author(s):  
Yu-bo Feng ◽  
Zong-jun Sun ◽  
Guang-yue Song ◽  
Sheng-nan Huang
Keyword(s):  
Function Analysis ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Single Pile ◽  
Interaction Function
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