Investigation of the mechanical properties of double lining structure of shield tunnel with different joint surface

2019 ◽  
Vol 90 ◽  
pp. 404-419 ◽  
Author(s):  
Shimin Wang ◽  
Lei Ruan ◽  
Xingzhu Shen ◽  
Weijie Dong
Keyword(s):  
Mechanical Properties ◽  
Joint Surface ◽  
Shield Tunnel ◽  
Lining Structure

scholarly journals Comparative Study on Mechanical Properties of Sealing Grease Composed of Different Base Oils for Shield Tunnel

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 692 ◽  
Author(s):  
Xiangqian Li ◽  
Yuyou Yang ◽  
Fan Li
Keyword(s):  
Mechanical Properties ◽  
Vegetable Oil ◽  
Exponential Function ◽  
Flow Rate ◽  
Temperature Sensitivity ◽  
Mineral Oil ◽  
Shield Tunnel ◽  
Fixed Temperature ◽  
Base Oil ◽  
Base Oils

This study proposes a novel sealing grease with improved mechanical properties and environmental performance. A series of sealing grease samples were made with different base oils, including mineral oil and renewable oil (vegetable oil and lard). In this study, thermogravimetric analysis (TGA) was conducted to study the adsorption capacity of the thickener to the base oil. The fluidity of the sealing grease was also tested at different temperatures. Furthermore, an exponential function was proposed for the flow rate of the sealing grease and the temperature. Moreover, a cone penetration test was conducted to study the consistency of the sealing grease. The results indicated that the capacity of the thickener to adsorb vegetable oil was greater than that of mineral oil, but less than that of lard. Additionally, the flow rate of the sealing grease increased with an increase in temperature. At a fixed temperature, the flow rate of the sealing grease increased with the base oil content. According to the exponential function, the composition of the base oil is the key factor that determines the temperature sensitivity of the sealing grease. In addition, the sealing grease made of vegetable oil has the minimum temperature sensitivity coefficient.

Effect of Time-Varying on Shield Tunnel Lining Structure

2014 ◽  
Vol 580-583 ◽  
pp. 987-990
Author(s):  
Feng Jun Liu ◽  
Jun Fang Chen
Keyword(s):  
Design Theory ◽  
Aging Effect ◽  
Tunnel Lining ◽  
Shield Tunnel ◽  
Time Varying ◽  
Bending Rigidity ◽  
Concrete Shrinkage ◽  
Lining Structure ◽  
Long Time ◽  
Internal Forces

In order to survey the time-varying effect on shield tunnel lining structure, rigidity reduce in the Homogeneous Ring Design Theory is introduced. There are three methods to evaluate the rigidity reduction caused by the aging effect. The first is the bending rigidity analysis method, which considers that the bending rigidity changes with the time-dependent stress and strain. The second is the method named the equivalent moment of inertia; the last is aging coefficient method. With the Homogeneous Ring Design Theory, the internal forces and displacement of the shield tunnel segment lining can be calculated. Based on the preliminary results, using the 1st method, the reduced rigidity and the long-time displacement at different instants of time can be calculated. It is found that the concrete shrinkage and creep effect can’t be ignored in the segment design. The survey is beneficial to monitor the deformation of tunnel lining, and the maintenance of the segments. It will make the tunnel work steadily and safely during the using period.

scholarly journals Experimental and Numerical Research on Defective Shield Segment under Cyclic Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Long-gang Tian ◽  
Zhi-qiang Hu ◽  
Jie Chen
Keyword(s):  
Cyclic Loading ◽  
Three Dimensional ◽  
Shield Tunnel ◽  
Vibration Loading ◽  
Lining Structure ◽  
Numerical Research ◽  
Scale Experiment ◽  
Tunnel System ◽  
Train Vibration ◽  
Good Agreement

The retaining structure of a shield tunnel is usually subjected to static loading; however, cyclic loading such as the vibration loading of the train will act on the lining structure year after year that cannot be neglected. Due to the complex manufacturing and assembling process of the lining segment, initial defects in the segment are inevitable. Such defects will propagate under the cyclic loading such as the train vibration, which may cause a large threat to the shield tunnel system. In this paper, a defective shield tunnel lining segment under cyclic loading is studied by both a full-scale experiment and three-dimensional numerical simulations to investigate its fracture properties and failure mechanism and make a rational estimate of its fatigue life. Results show that crack propagation of the defective shield tunnel segment can be identified as several different stages based on its deformation characteristics, and the failure pattern of the segment is determined by its initial defects. The results by the experiment and numerical investigation are in good agreement for each other.

scholarly journals Mechanical Properties of Polypropylene Macrofiber-Reinforced Concrete

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Zhishu Yao ◽  
Xiang Li ◽  
Cao Fu ◽  
Weipei Xue
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Raw Materials ◽  
Plain Concrete ◽  
Difficult Problem ◽  
Test Results ◽  
Mine Shaft ◽  
Technical Parameters ◽  
Geological Conditions ◽  
Lining Structure

To economically and reasonably solve the difficult problem of mine shaft support subject to complex geological conditions, we studied the mechanical properties of polypropylene macrofiber-reinforced concrete (PPMFRC). First, we selected test raw materials through an investigation and comparison of technical parameters. Second, using a preparation test, we obtained the composition of reference concrete of PPMFRC for the mine shaft lining structure, and test specimens were manufactured according to relevant test technical regulations. Finally, the mechanical properties of the specimens were compared, and the results show that the compressive, flexural, and tensile strengths of PPMFRC were increased by approximately 3%, 30%, and 20%, respectively, for mixtures with polypropylene macrofibers. The fracture toughness of PPMFRC was between 0.26 and 0.35, and the fracture energy was between 382.7 N/m and 485.6 N/m, which is significantly higher than that of plain concrete. The test results show that PPMFRC is an ideal material for the lining structure of a mine shaft under complex geological conditions, and we have provided technical parameters for engineering applications.

Construction Process Numerical Simulation and Experimental Research of Parallel-Adjacent Loess Tunnel

2012 ◽  
Vol 446-449 ◽  
pp. 2186-2191
Author(s):  
Jian Guo ◽  
Qi Cai Wang ◽  
Rong Ling Zhang ◽  
Zhi Guo Yang
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Experimental Research ◽  
Tunnel Lining ◽  
Tunnel Construction ◽  
Construction Process ◽  
Tunnel Excavation ◽  
Lining Structure ◽  
Loess Region ◽  
The Impact

According to the mechanical properties of the parallel-adjective tunnel, the construction process is simulated and the displacements and concrete stress of the lining structure is monitored of an actual tunnel in the loess region. The influence which the new tunnel on the existing tunnel lining during the new tunnel construction process studied by comparatively analyzed the numerical simulation and monitoring the results. The results show that the impact on the existing tunnel during the new tunnel excavation changes with tunnel distance and the excavation method of the new tunnel, when the line distance increases the impact on the existing tunnel has been remarkably reduced.

The Research and Application on Calculation Model of the Stagger-Jointed Assemble Lining Structure

2010 ◽  
Vol 163-167 ◽  
pp. 1823-1828
Author(s):  
An Long Jiang ◽  
Zhao Yang
Keyword(s):  
Shear Force ◽  
Yellow River ◽  
Calculation Model ◽  
Contact Element ◽  
Secondary Development ◽  
Joint Surface ◽  
Adjacent Area ◽  
Development Platform ◽  
Lining Structure

A new calculation model of stagger-joint assemble is presented. The model can reflect three ways to transfer shear force between adjacent rings. To simplify the calculation model, a friction shear contact element is coded on ABAQUS secondary development platform and the nut of bolt is embedded in the segment. Using the model to analysis the Tunnel Through Yellow River, the results show that the integral rigidity of the lining structure improve obviously and the local modify effective have an impact on the adjacent area near ring-joint surface more than away from area.

scholarly journals Analysis of Changes in the Micromorphology of Sandstone Joint Surface under Dry-Wet Cycling

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jingcheng Fang ◽  
Huafeng Deng ◽  
Yu Qi ◽  
Yao Xiao ◽  
Hengbin Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Friction Angle ◽  
Jointed Rock ◽  
Joint Surface ◽  
Roughness Coefficient ◽  
Rock Masses ◽  
Jointed Rock Masses ◽  
Bank Slope ◽  
Steep Decrease ◽  
The Face

Changes in the micromorphology of joint surface under dry-wet cycling have a direct effect on the mechanical properties of the jointed rock masses, which in turn affects the deformation stability of the bank slope of a reservoir. In this study, we design and carry out a test that aims to quantity the effects of repeated rise and fall of a reservoir on the properties of a jointed rock masses. The results are as follows: first, the roughness, local gradient, and undulation of the joint surface gradually decreased under repeated dry-wet cycling. In addition, the height parameters and texture parameters showed a steep decrease followed by a slow decline. The deterioration was particularly obvious over the first 5 dry-wet cycles. Second, the roughness coefficient of the joint surface, the compressive strength of the face wall, and the basic friction angle were gradually reduced under dry-wet cycling. The shear strength of the jointed rock masses (obtained both quantitatively and experimentally) showed a deteriorating trend controlled by the deterioration of the micromorphology, the strength of the face wall, and the frictional properties of the joint surface. Finally, the dry-wet cycling process determined trends of changes in the microstructure parameters and mechanical properties of the joint surface. Our research results provide a good basis for the analysis of the deterioration and failure of rock masses within the hydrofluctuation belt of a bank slope.

Study on Design of Working Shaft for Oil and Natural Gas Pipe in Cross River Slurry Shield Tunnel

2013 ◽  
Vol 405-408 ◽  
pp. 1268-1272 ◽  
Author(s):  
Xiao Jun Zhou ◽  
He Ran Yu ◽  
Xiao Feng Wang ◽  
Hong Yun Hu
Keyword(s):  
Natural Gas ◽  
Water Pressure ◽  
Elastic Stability ◽  
Building Envelope ◽  
Concrete Lining ◽  
Shield Tunnel ◽  
Lining Structure ◽  
Oil And Natural Gas ◽  
Slurry Shield ◽  
Shield Machine

In terms of oil and natural gas pipe to be installed in working shaft, and in light of basic dimension of slurry shield machine and its supporting system, required parameters of working shaft, such as its diameter, lining structure, building envelope have been presented in this paper. Meanwhile, the thickness of building envelope and permanent concrete lining for working shaft is also proposed through the analysis of its elastic stability and anti-buoyancy under influence of earth and ground water pressure.

Three-Dimensional Dynamic Response Analysis of Shield Tunnel under Train Loads

2011 ◽  
Vol 90-93 ◽  
pp. 2062-2067 ◽  
Author(s):  
Zhan Rui Wu ◽  
Tai Yue Qi ◽  
Lin Zhong
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Three Dimensional ◽  
Shield Tunnel ◽  
Response Analysis ◽  
High Speed Train ◽  
Lining Structure ◽  
Design Speed

The vibration loads will be produced between wheel and rail on the running of the high-speed Train. The vibration energy will be transferred to the ground formation through the rail, guiding bed and tunnel lining structure, thereby causing vibration between the formation and surface and environmental interference effect problems. Thus the research of related issues caused by the high-speed train vibration has the vital great significance. The train design speed of the Shiziyang shield tunnel for Guangzhou-Shenzhen-Hong Kong passenger dedicated line is up to 350km/h. In this paper the research object is located in the segment of the homogeneous formation of the Shiziyang shield tunnel. The analysis of this paper includes the dynamic response rules of the shield tunnel and formation under the single high-speed train loads and the law of the pore water pressure accumulation and dispersion under train cyclic loading.

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