Numerical simulation study on permeability and humectant properties of coal seam water injection under high water pressure in long drilling hole

2014 ◽  
pp. 851-856
Author(s):  
Y Yu ◽  
W Cheng ◽  
G Zhou ◽  
L Chen ◽  
L Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Simulation Study ◽  
Water Pressure ◽  
Water Injection ◽  
High Water ◽  
Drilling Hole ◽  
High Water Pressure

scholarly journals Numerical Simulation Three-Dimensional Nonlinear Seepage in a Pumped-Storage Power Station: Case Study

Energies ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 180 ◽  
Author(s):  
Shaohua Hu ◽  
Xinlong Zhou ◽  
Yi Luo ◽  
Guang Zhang
Keyword(s):  
Numerical Simulation ◽  
Water Pressure ◽  
Flow Theory ◽  
High Water ◽  
Control Measures ◽  
Nonlinear Flow ◽  
Heaviside Function ◽  
Power Station ◽  
Pumped Storage ◽  
High Water Pressure

Due to high water pressure in the concrete reinforced hydraulic tunnels, surrounding rocks are confronted with nonlinear seepage problem in the pumped storage power station. In this study, to conduct nonlinear seepage numerical simulation, a nonlinear seepage numerical model combining the Forchheimer nonlinear flow theory, the discrete variational inequality formulation of Signorini’s type and an adaptive penalized Heaviside function is established. This numerical seepage model is employed to the seepage analysis of the hydraulic tunnel surrounding rocks in the Yangjiang pumped-storage power station, which is the highest water pressure tunnel under construction in China. Moreover, the permeability of the surrounding rocks under high water pressure is determined by high pressure packer test and its approximate analytical model. It is shown that the flow in the surrounding rocks is particularly prone to become nonlinear as a result of the high flow velocities and hydraulic gradients in the nearby of the seepage-control measures and the high permeability fault. The nonlinear flow theory generates smaller flow rate than the Darcy flow theory. With the increase of nonlinear flow, this observation would become more remarkable.

scholarly journals Study on Mechanical Characteristics of Segmental Joints of a Large-Diameter Shield Tunnel under Ultrahigh Water Pressure

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8392
Author(s):  
Lei Kou ◽  
Zhihui Xiong ◽  
Hao Cui ◽  
Jinjie Zhao
Keyword(s):  
Numerical Simulation ◽  
Theoretical Calculation ◽  
Water Pressure ◽  
Concrete Strength ◽  
Large Diameter ◽  
Simulation Method ◽  
High Water ◽  
Calculation Model ◽  
Bending Stiffness ◽  
High Water Pressure

At present, there is no clear design standard for segmental joints of large-diameter shield tunnels under high water pressure. In this paper, a theoretical calculation model for the bending stiffness of segmental joints under high water pressure is proposed. The numerical simulation method is used to investigate the failure and crack formation processes of single-layer and double-layer lining segments under large axial forces. The effects of axial force, bolt strength, and concrete strength on the bending stiffness of joints are then studied using a theoretical calculation model of segmental joints. The results show that under extremely high water pressure, the influence of double lining on joint stiffness is limited. It is more rational and safe to compute the bending stiffness of segmental joints using this theoretical model rather than the numerical simulation method. The parameter analysis reveals that increasing the bolt strength has a minor impact on bending stiffness and deformation, whereas increasing the concrete strength has the opposite effect. The influence of ultimate bearing capacity and deformation decreases non-linearly as the axial force increases.

Development and Experimental Research on a Formula of Water Inrush Coefficient

2013 ◽  
Vol 448-453 ◽  
pp. 3901-3907
Author(s):  
Gan Tian
Keyword(s):  
High Pressure ◽  
Coal Seam ◽  
Water Resistance ◽  
Water Pressure ◽  
Water Inrush ◽  
High Water ◽  
Residual Pressure ◽  
Simulation Experiments ◽  
Pressure Water ◽  
High Water Pressure

Based on analysis of water inrush coefficients developed and applied in deep coal mining with high water pressure, the author proposes that there are some defects of water inrush coefficients in calculation and application. By simulation experiments on the water resistance properties of the aquiclude in a coal seam floor, the author arrived at the distribution and digital characteristics of residual pressure in the course of high-pressure water rising in the water-resisting floor. The formula for a water inrush coefficient has been further revised.

scholarly journals Structural modifications of lanthanum silicate oxyapatite exposed to high water pressure

2017 ◽  
Vol 37 (5) ◽  
pp. 2149-2158 ◽  
Author(s):  
Aénor Pons ◽  
Emilie Béchade ◽  
Jenny Jouin ◽  
Maggy Colas ◽  
Pierre-Marie Geffroy ◽  
...  
Keyword(s):  
Water Pressure ◽  
High Water ◽  
Structural Modifications ◽  
Lanthanum Silicate ◽  
High Water Pressure

scholarly journals Analysis on Water Inrush Process of Tunnel with Large Buried Depth and High Water Pressure

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 134 ◽  
Author(s):  
Weimin Yang ◽  
Zhongdong Fang ◽  
Hao Wang ◽  
Liping Li ◽  
Shaoshuai Shi ◽  
...  
Keyword(s):  
High Pressure ◽  
Model Test ◽  
Water Pressure ◽  
Water Inrush ◽  
High Water ◽  
Surrounding Rock ◽  
Karst Cave ◽  
Tunnel Excavation ◽  
Pressure Water ◽  
High Water Pressure

In order to explore the catastrophic evolution process for karst cave water inrush in large buried depth and high water pressure tunnels, a model test system was developed, and a similar fluid–solid coupled material was found. A model of the catastrophic evolution of water inrush was developed based on the Xiema Tunnel, and the experimental section was simulated using the finite element method. By analyzing the interaction between groundwater and the surrounding rocks during tunnel excavation, the law of occurrence of water inrush disaster was summarized. The water inrush process of a karst cave containing high-pressure water was divided into three stages: the production of a water flowing fracture, the expansion of the water flowing fracture, and the connection of the water flowing fracture. The main cause of water inrush in karst caves is the penetration and weakening of high-pressure water on the surrounding rock. This effect is becoming more and more obvious as tunnel excavation progresses. The numerical simulation results showed that the outburst prevention thickness of the surrounding rock is 4.5 m, and that of the model test result is 5 m. Thus, the results of the two methods are relatively close to each other. This work is important for studying the impact of groundwater on underground engineering, and it is of great significance to avoid water inrush in tunnels.

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