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.

Improvements on Technologies of Shield Tunnel Construction in Sandy Soil

2012 ◽  
Vol 226-228 ◽  
pp. 957-962
Author(s):  
Zhan Wang ◽  
Guan Shui Liu ◽  
Fan Long ◽  
Fei Zheng
Keyword(s):  
Sandy Soil ◽  
Ventilation System ◽  
Cooling Water ◽  
Conveyor Belt ◽  
Shield Tunnel ◽  
Circulation System ◽  
Tunnel Construction ◽  
Shield Tunneling ◽  
Tunneling Method ◽  
Water Circulation System

With development of underground space, the shield tunneling method have been widely adopted due to its unique advantages. However, there is still many technical and theoretical problems need to be improved in the construction. Based on the project of metro line 1 in Hangzhou city, typical problems of shield tunnel construction in sandy soil are analyzed. The problems of ventilation system, cooling water circulation system, foaming system and conveyor belt system are represented in detail. Controlling of proper propelling force is optimized by parameter sensibility analysis. Aiming at these problems, improvement measures are proposed and successfully used in the project. The improvements can be taken for reference in similar projects.

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.

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.

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.

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.

Ground Treatment and its Application in Shallow Subway Tunnel Crossing Urban River by Shield Tunneling Method

2014 ◽  
Vol 919-921 ◽  
pp. 853-856 ◽  
Author(s):  
Xiao Jun Zhou
Keyword(s):  
Surrounding Rock ◽  
Shield Tunnel ◽  
Great Success ◽  
Treatment Technique ◽  
Subway Tunnel ◽  
Shield Tunneling ◽  
Ground Treatment ◽  
Reinforced Concrete Slabs ◽  
Tunneling Method ◽  
Shallow Subway

On the basis of the geological and environmental conditions of surrounding rock around a shallow subway tunnel used to cross a river in Chengdu subway line one, the ground treatment technique such as uplift piles, cast-in-place reinforced concrete slabs and site grouting have been summarized in the paper. The riverbed above shallow shield tunnel is reinforced with covering slabs and uplift piles; meanwhile, the surrounding rock is reinforced with cement and sodium silicate grout by high pressure grouting method conducted inside the tunnel. The practice of the scenario presented in the paper turns out to be a great success and shows that the treatment technique can be used to guide the design and construction of ground reinforcement for shallow tunnel used to cross urban rivers in subway lines by shield tunneling method under similar conditions.

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.

Shield Tunneling Parameters Optimization Based on Dynamic Bayesian Networks

2014 ◽  
Vol 941-944 ◽  
pp. 921-927
Author(s):  
Tie Mei Zeng ◽  
Bao Jun Ding ◽  
Yan Hong Wang ◽  
Li Mao Zhang
Keyword(s):  
Optimization Method ◽  
Dynamic Bayesian Networks ◽  
Surface Subsidence ◽  
Parameters Optimization ◽  
Monitoring Data ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Parameter Learning ◽  
Shield Tunneling ◽  
Network Nodes

To control the surface subsidence in shield tunnel construction, a DBN-based, parameters optimization method was proposed and applied to a tunnel project in Wuhan, China. Selected the construction parameters to optimize as network nodes and set discretizing rules to determine the nodes domain, then discretized monitoring data and applied them to parameter learning to obtain complete DBN model. This model was validated with engineering measured data , then applied it to determine the setting optimal operating-range of each parameters and within that optimized the parameters real-timely according to the monitoring data changing. The results show that this model can reflect the inner link between the surface subsidence and shield construction parameters and this DBN-based method can control the surface subsidence in shield tunnel construction effectively.

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