Analytical Solution for the External Stress Acting on the Lining in a Deep-Buried Circular TBM Tunnel Considering the Seepage Field

2019 ◽  
Keyword(s):  
Analytical Solution ◽  
External Stress ◽  
Seepage Field

scholarly journals Analytical Solution of Seepage Field in Karst Tunnel

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Chong Jiang ◽  
Han-song Xie ◽  
Jia-li He ◽  
Wen-yan Wu ◽  
Zhi-chao Zhang
Keyword(s):  
Analytical Solution ◽  
Permeability Coefficient ◽  
Complex Function ◽  
Great Influence ◽  
Pressure Head ◽  
Seepage Flow ◽  
Seepage Field ◽  
Karst Tunnel ◽  
Lining Structure ◽  
Initial Support

An analytical solution for the seepage field in water-filled karst tunnel is derived based on the inversion of complex function and groundwater hydraulics theory. The solution considers the distance between the tunnel and the cavern, the size of the cavern, and the properties of the lining structure, such as the permeability coefficient as well as the radius of the grouting ring. This paper also performed numerical simulations for two cases: the application of gravity and the absence of gravity. The numerical solution was obtained to verify the analytical solution, and a good agreement was found. Then, the effect of parameters is discussed in detail, including the distance between the tunnel and the cavern, the radius of the cavern, the grouting ring, and the initial support. The results show that when the radius of the cavern is constant, the pressure head and seepage flow decrease as the distance between the tunnel and the cavern increases. When the distance is constant, the pressure head and seepage flow increase with the increase of the radius of the cavern. In addition, the pressure head and the seepage flow decrease with the increase of the thickness of the grouting ring and decrease with the decrease of the permeability coefficient. As the thickness of the initial support increases, the pressure head gradually increases and the percolation decreases. Furthermore, due to the great influence of the grouting ring and initial support on the pressure head and seepage flow, the thickness and permeability coefficient of the grouting ring and initial support should be taken into account carefully during construction.

scholarly journals Analytical Solution of Steady-State Temperature Field of Single Freezing Pipe under Action of Seepage Field

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Bin Wang ◽  
Chuanxin Rong ◽  
Hua Cheng ◽  
Haibing Cai ◽  
Shiqi Zhang
Keyword(s):  
Temperature Field ◽  
Steady State ◽  
Analytical Solution ◽  
Model Test ◽  
Freezing Temperature ◽  
Seepage Velocity ◽  
Distribution Law ◽  
Seepage Field ◽  
Steady State Temperature ◽  
Single Pipe

To accurately describe the distribution law of the temperature field formed by a single freezing pipe under the action of a seepage field, the shape of the freezing front was simplified using a segmentation-equivalent method. The analytical solution of the steady-state temperature field was derived, and the accuracy was verified using a physical model test. Combined with the results of the model test and the calculation results of the analytical solution, the distribution law of the freezing temperature field formed by a single pipe under different seepage velocities was analyzed. It was found that compared with the no flow rate, when the seepage velocity was 3, 6, and 9 m/day, the frozen area was reduced from 17.97 × 104 mm2 to 15.77 × 104, 3.84 × 104, and 3.05 × 104 mm2, respectively. The proportion of frozen area below −5°C increased from 39.43% to 40.19%, 49.84%, and 51.52%, respectively. The average freezing temperature field reduced from −5.78 to −5.86, −7.31, and −7.50°C, respectively. As the seepage velocity increased, the frozen area formed by a single pipe decreased while the proportion of the low-temperature zone increased and the average temperature of the temperature field decreased.

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