Influence Law of Structural Inclination for the Advanced Excavation Method of the Tunnel

2013 ◽  
Vol 368-370 ◽  
pp. 1464-1467
Author(s):  
Chao Gao ◽  
Lei Chen ◽  
Shang Lun Liu
Keyword(s):  
Numerical Calculation ◽  
Hard Rock ◽  
Surrounding Rock ◽  
Tunnel Construction ◽  
Geological Condition ◽  
Construction Process ◽  
Rock Stability ◽  
Highway Tunnel ◽  
Calculation Results ◽  
Ground Stress

A deep-buried highway tunnel is constructed with complex geological condition which existing an alternation of soft and hard rock and having feature of high ground stress, and extrusion, fall-block and twisted phenomena of supporting structure appear in many places during construction which pose a serious threat to the safety of tunnel construction. In combination with the construction process of Shimenya tunnel, by using the finite difference software FLAC3D, the surrounding rock stability is simulated, and the numerical calculation results of advanced pilot excavation method with different structural inclinations. The conclusion can be used for reference for the design and research of similar tunnels.

Loess Highway Tunnel Construction Process of Three Dimensional Numerical Simulation

2012 ◽  
Vol 256-259 ◽  
pp. 1276-1279
Author(s):  
Bai Liu ◽  
Bin Zhang ◽  
Jing Kong ◽  
Jian Pang
Keyword(s):  
Three Dimensional ◽  
Shanxi Province ◽  
Tunnel Construction ◽  
Western Region ◽  
High Grade ◽  
Construction Process ◽  
Construction Technique ◽  
Loess Area ◽  
Highway Tunnel ◽  
Deformation Law

In recent years, as China's national sustained and rapid economic development, the state increased investment to middle-western region, promote the regional development of high grade highway. Therefore, highway tunnel through loess area is getting more and more. Due to the special physical properties of loess, it makes the loess tunnel construction a hot topic. To study on the deformation law of the loess highway tunnel, this paper based on the Shanxi Province Guang Ling to Hun Yuan highway tunnel—East Fu Yao tunnel, we simulate the whole section pre-reinforcement construction technique for three dimensional numerical, and combined with field monitoring measurement to compare and analyze in paper

Study on Surrounding Rock Stability of Small Clear-Distance Twin Highway Tunnel with Eight Lanes

2018 ◽  
Vol 37 (2) ◽  
pp. 593-598 ◽  
Author(s):  
Qing Jiang ◽  
Shu-guang Song ◽  
Tao Li ◽  
Kang Wang ◽  
Rui-hai Gu
Keyword(s):  
Surrounding Rock ◽  
Rock Stability ◽  
Highway Tunnel ◽  
Clear Distance

scholarly journals New Construction Technology of a Shallow Tunnel in Boulder-Cobble Mixed Grounds

2020 ◽  
Vol 2020 ◽  
pp. 1-20 ◽  
Author(s):  
Tong Liu ◽  
Yujian Zhong ◽  
Zhihua Feng ◽  
Wei Xu ◽  
Feiting Song ◽  
...  
Keyword(s):  
Surrounding Rock ◽  
Construction Technology ◽  
Construction Process ◽  
Tunnel Excavation ◽  
Supporting System ◽  
Highway Tunnel ◽  
Bulk Medium ◽  
New Construction ◽  
Secondary Lining ◽  
Design And Construction

As a typical granular bulk medium, problems are common in boulder-cobble mixed grounds, such as easy collapse and instability and difficult effective support for large-section tunnel excavation. Tunnels constructed in BCM grounds are rare still, and there is a big gap between the design and construction of tunnels. Based on the Nianggaicun highway tunnel crossing the BCM grounds, the construction technology of tunnel in BCM grounds is studied by means of literature investigation and field survey. Here are the main conclusions: the overall deformation of surrounding rock is quite small; the pressure distribution of surrounding rock is small and loose pressure is dominant, and the safety reserve of secondary lining is large. The deformation process of surrounding rock concentrates on the construction stage. During the construction process, there are many problems, such as serious overexcavation, difficulty of bolt penetration, and continuous rock fall. In this paper, a three-bench complementary cyclic excavation method is proposed, which replaces the original CD and CRD methods. Meanwhile, the supporting system is optimized. The results show that the disturbance of surrounding rock is reduced, while the safety of construction process and the reliability of structure are increased. The new excavation method and optimized supporting system are expected to fill the gap between design and construction of tunnel in BCM grounds and provide reference for construction of such tunnels in the future.

Instability Mechanism of Du Yun Pass Tunnel Entrance Weathered Stacking Area Analysis

2016 ◽  
Vol 858 ◽  
pp. 81-85
Author(s):  
Lin Liu ◽  
Yao Rong ◽  
Cheng Ke Zhang ◽  
Meng Yun Mao ◽  
Lu Lin Zhang
Keyword(s):  
Pile Foundation ◽  
Stability Problem ◽  
Surrounding Rock ◽  
Geological Condition ◽  
Construction Process ◽  
Instability Mechanism ◽  
Construction Scheme ◽  
The Stability ◽  
Tunnel Portal ◽  
Tunnel Entrance

The stability of the tunnel portal section under poor terrain and geological condition has always been the focus of construction safety. The stability problem has become more complex for the erosion accumulation area under the valley. In this paper, firstly the stability of the tunnel portal is classified. Combined with engineering cases, the FEM numerical method is used to simulate the supporting structure and construction process of the tunnel. Based on the distribution of the plastic zone and displacement of surrounding rock, the mechanism of the instability of the tunnel portal is analyzed. Through the optimized construction scheme that arranges pile foundation in tunnel arch foundation, the bearing capacity of foundation has been greatly improved, which has effectively prevented the instability of surrounding rock caused by the slope deformation and foundation settlement. The conclusions that have been drawn in this paper can be used for reference for related projects.

Analysis of Mechanical Behavior of Subway Tunnel Constructed by Cover and Cut Reverse Method

2012 ◽  
Vol 446-449 ◽  
pp. 3623-3627
Author(s):  
Tie Cheng Wang ◽  
Yang Gao ◽  
Hai Long Zhao
Keyword(s):  
Bending Moment ◽  
Horizontal Displacement ◽  
Internal Force ◽  
Surrounding Rock ◽  
Diaphragm Wall ◽  
Tunnel Construction ◽  
Construction Process ◽  
Subway Tunnel ◽  
Diaphragm Walls ◽  
Reverse Method

In the paper, not only the internal force and displacement of structure during subway tunnel construction with cover and cut reverse method, but also the displacement field and stress field of surrounding rock are analysed. From the numerical calculation it is shown that the bending moment of diaphragm wall is affected seriously by the distribution and value of the stiffness of horizontal support; the excavation phase of the soil of the second floor underground is the key phase of the construction process because the internal force of structure has large increase; the value of surface settlement, horizontal displacement of diaphragm wall, differential settlement between middle pillar and diaphragm walls all meet the requirements, so the construction is safe and the surrounding buildings are affected slightly.

Stability Analysis of Tunnel during the Excavation Based on ANSYS

2014 ◽  
Vol 577 ◽  
pp. 1135-1138
Author(s):  
Bing He ◽  
Guang Zhi Yin
Keyword(s):  
Numerical Simulation ◽  
Stability Analysis ◽  
Stress Condition ◽  
Stability Control ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Geological Condition ◽  
Rock Stability ◽  
Before And After ◽  
The Stability

This paper combines the geological condition of Miaoziwan tunnel and numerical simulation software ANSYS to analyze the displacement and stress condition of surrounding rock before and after the excavation. Furthermore, the stability of overlying rock in the tunnel was studied based on the displacement and stress condition of surrounding rock. The breaking law of overlying rock was studied considering the influencing factors to the stability of surrounding. The study and analysis to the breaking law of overlying rock can be helpful to the improvement of surrounding rock stability control and supporting system. Moreover, the result can be the guidance to the excavation.

A New Technique for Construction of Limestone Cave

2015 ◽  
Vol 648 ◽  
pp. 9-16
Author(s):  
Bao Jin ◽  
Hong Jun Zhang ◽  
Jian Yang Zhang
Keyword(s):  
Stress Distribution ◽  
Mechanical Damage ◽  
Surrounding Rock ◽  
Tunnel Construction ◽  
Quality And Safety ◽  
Construction Process ◽  
Risk And Uncertainty ◽  
A New Technique ◽  
The Stability ◽  
Efficient Measures

A cave is formed when surface water and groundwater effect on soluble rocks through chemical and mechanical damage. That is called karst phenomenon. It will affect the stability and stress distribution of the surrounding rock. Part of the tunnel construction process will affect the stress distribution of the surrounding rock greatly. Some caves are unavoidable, which could make structures insecurity and instability. At the same time, the construction process will become complicated. Caves will increase the risk and uncertainty of the whole project as well. Therefore, the development of scientific and efficient measures to ensure the quality and safety of the construction project becomes extremely important. In this paper several safety precautions would be introduced based on the specific case of tunnel construction. And experience will be given in order to benefit the construction of similar problems.

Studies on Influence of Tunnel Surrounding Rock Stability Analysis Based on Material Yield Criterions

2011 ◽  
Vol 90-93 ◽  
pp. 501-507
Author(s):  
Mu Kun Huang ◽  
Xiao Guang Jin ◽  
Yan Wang ◽  
Ling Zhu
Keyword(s):  
Stability Analysis ◽  
Yield Criterion ◽  
Surrounding Rock ◽  
Tunnel Construction ◽  
Rock Stability ◽  
Element Simulation ◽  
Angle Point ◽  
Rock Tunnel ◽  
Weak Surrounding Rock ◽  
The Impact

Numerical simulation is one of main methods for tunnel surrounding rock stability analysis. By now, there hasn’t be unanimous view on that what kind of yield criterion is adopted for different surrounding rock class and different buried depth. Mohr-Coulomb yield criterion is always adopted abroad, Drucker-Prager yield criterion is always adopted in China, moreover, the principles are different when adopting D-P yield criterion at home and abroad. Based on introducing the Mohr-Coulomb yield criterion and D-P yield criterions, this paper uses the M-C exterior angle point of circle criteria, which is popular in the international arena for the D-P yield criterion, and finds parameters of geotechnical material for D-P yield criterions through the parameter transformation. Combining with 3D elastic-plastic finite element simulation of the tunnel construction process, with the tunnel buried by soft and weak surrounding rock (V class) at shallow (15m) and deep (550m), this paper analyzes the impact of the M-C and D-P yield criterions on surrounding rock’s displacement, stress, strain effects, and proposes the appropriate yield criterion for the simulation of shallow and deep soft and weak rock tunnel construction and for tunnel surrounding rock stability analysis.

Research on Stability in Metro Tunnel Constructing with Shallow Buried Covered Excavation in Loose Sand Layers

2012 ◽  
Vol 594-597 ◽  
pp. 1240-1244
Author(s):  
Shen Gang Li ◽  
Wen Zhao ◽  
Xiao Li Cai ◽  
Yin Fu Ma ◽  
Lu Zhang
Keyword(s):  
Numerical Calculation ◽  
Side Wall ◽  
Tunnel Construction ◽  
Loose Sand ◽  
Ground Settlement ◽  
Single Side ◽  
Calculation Results ◽  
Metro Tunnel

For subway tunneling in urban underground, high safty of construction is needed.However, the safty and rationality of excavating plan are forecasted difficultly because of consealment. Based on the Zhang-Shen tunnel construction of Shenyang subway, bench method, single side-wall heading excavation method and CD excavation method are numerical simulated; according to the numerical calculation results and the constructing process, bench method is adopted; the ground settlement caused by excavation monitored during excavating is in the allowed range and the tunnel is safe during excavating.

Instability Mechanism and Supporting Measure for Highway Tunnel with High Ground Stress and Soft Surrounding Rock

2014 ◽  
Vol 1049-1050 ◽  
pp. 213-216 ◽  
Author(s):  
Xiao Hui Xue ◽  
Zhong Ming Su ◽  
Zhi Jie Sun ◽  
Fei Song
Keyword(s):  
Field Monitoring ◽  
Surrounding Rock ◽  
Instability Mechanism ◽  
Geological Investigation ◽  
Highway Tunnel ◽  
Foamed Concrete ◽  
Ground Stress ◽  
Supporting Effect ◽  
Grouting Reinforcement ◽  
Deformation Instability

For the tunnel with high ground stress and soft surrounding rock, the deformation instability is the high frequency and great harm geological hazard. The supporting measure has become a important technique problem. This paper based on the Wuduxi tunnel, the characteristics of deformation and instability mechanism of surrounding rock and supporting structure are analyzed by means of the engineering geological investigation, theoretical analysis and field monitoring. The supporting measure include that using the steel floral tube to back up sidewall, adding support arch and filling foamed concrete, grouting reinforcement in basement. Finally, we use the field monitoring to check the supporting effect. The result shows that the supporting measure could achieve the desired treat effect and it has reference meaning to similar engineering.

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