Flow Characteristics and Escape-Route Optimization after Water Inrush in a Backward-Excavated Karst Tunnel

2017 ◽  
Vol 17 (4) ◽  
pp. 04016096 ◽  
Author(s):  
J. Wu ◽  
S. C. Li ◽  
Z. H. Xu ◽  
X. Huang ◽  
Y. G. Xue ◽  
...  
Keyword(s):  
Water Inrush ◽  
Flow Characteristics ◽  
Route Optimization ◽  
Karst Tunnel ◽  
Escape Route

scholarly journals Evolution Pattern and Matching Mode of Precursor Information about Water Inrush in a Karst Tunnel

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1579
Author(s):  
Jie Song ◽  
Diyang Chen ◽  
Jing Wang ◽  
Yufeng Bi ◽  
Shang Liu ◽  
...  
Keyword(s):  
Rock Mass ◽  
Stress Field ◽  
Displacement Field ◽  
Water Inrush ◽  
Seepage Field ◽  
Karst Tunnel ◽  
Rock Mass Structure ◽  
Evolution Pattern ◽  
Water Blocking ◽  
Precursor Information

The water inrush of the Shangjiawan karst tunnel is used to study the evolution pattern of precursor water inrush information in water-filled caves and to further reveal the matching mode of the information. The three-dimensional numerical method FLAC3D was used to simulate the evolution process of water inrush after damage to a water-blocking rock mass structure in a water-filled cave and to obtain the evolution pattern of precursor water-inrush information caused by the damage. The results show that the multifield response to the characteristic precursor information of the water-inrush pattern after the fracture of the water-blocking rock mass follows the order of stress-field displacement-field seepage-field. Further, the matching pattern of the information shows that the stress field increased first and then decreased, the displacement field always increased, and the seepage field increased first and then decreased.

scholarly journals Experimental Investigation of Water-Sand Mixed Fluid Initiation and Migration in Filling Fracture Network during Water Inrush

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Bin Yang ◽  
Tianhong Yang
Keyword(s):  
Particle Size ◽  
Critical Velocity ◽  
Network Flow ◽  
Water Inrush ◽  
Functional Relation ◽  
Flow Characteristics ◽  
Fracture Network ◽  
Nonlinear Flow ◽  
Two Phase ◽  
And Migration

For water inrush induced by fracture network flow, the critical velocity of the incipient motion of sand particles was obtained, and the functional relation between critical velocity and particle size was established through a series of tests on the nonlinear flow characteristics of a filling fracture network. The influence of the particle size distribution, hydrodynamic force, and geometric features of the fracture network on the characteristics of particle loss; distribution laws; and water-sand, two-phase migration was also explored. Moreover, the interactions amongst water, movable particles, the surface of the skeleton, and fracture walls, and the formation mechanism of the flow channel were qualitatively analyzed. In addition, the change rules of the mass loss characteristics and porosity of the samples with time were tested successfully. The calculation methods of the permeability and non-Darcy factor of the filling fracture network were also determined.

Escape route optimization by cellular automata based on the multiple factors during the coal mine disasters

2019 ◽  
Vol 99 (1) ◽  
pp. 91-115
Author(s):  
Kai Wang ◽  
Haiqing Hao ◽  
Shuguang Jiang ◽  
Zhengyan Wu ◽  
Chuanbo Cui ◽  
...  
Keyword(s):  
Cellular Automata ◽  
Coal Mine ◽  
Route Optimization ◽  
Escape Route ◽  
Multiple Factors

Mine Water Irruption Flooding Spread Route Generation Algorithm Based on Directed Graph

2012 ◽  
Vol 268-270 ◽  
pp. 1894-1897
Author(s):  
Hui Fu ◽  
Shan Jun Mao ◽  
Yun Xiu Luo
Keyword(s):  
Mine Water ◽  
Water Inrush ◽  
Scientific Basis ◽  
Route Optimization ◽  
Generation Algorithm ◽  
Emergency Rescue ◽  
Point Extension ◽  
Starting Point ◽  
Control Work ◽  
And Control

In view of roadway complex spatial relationships, the lack of visual expression in the mine water prevention and control work, this paper gives the water irruption flooding spread generation algorithm. Based on building tree topology from water inrush starting point extension and simulating of water down to spread and water level to rise, the algorithm generates flooding route and establishes water inrush 3D simulation system. It provides scientific basis for developing disaster relief route optimization and emergency rescue decision-making.

scholarly journals Theoretical Analysis of Safety Thickness of the Water-Resistant Rock Mass of Karst Tunnel Face Taking Into Account Seepage Effect

2021 ◽  
Author(s):  
Jiaqi GUO ◽  
Wenlong Wu ◽  
Xiliang Liu ◽  
Xin Huang ◽  
Zhengguo Zhu
Keyword(s):  
Rock Mass ◽  
Influencing Factors ◽  
Water Pressure ◽  
Water Inrush ◽  
Surrounding Rock ◽  
Karst Water ◽  
Seepage Force ◽  
Karst Tunnel ◽  
Tunnel Face ◽  
Safety Thickness

Abstract This paper took into account the adverse influence of the karst water seepage effect on the water-resistant rock mass. Based on the upper-bound theorem of limit analysis and the Hoek-Brown failure criterion, through a series of formula derivation, the expression of critical safety thickness of water-resistant rock mass of karst tunnel face was finally obtained. The paper carried out a feasibility analysis, an analysis of influencing factors and a comparative analysis with previous related research achievements of this method. The results showed that: (1) With the decrease of surrounding rock grade, the safety thickness of water-resistant rock mass gradually increased, and the safety thickness of surrounding rock at all grades remained within a reasonable range. (2) The safety thickness decreased as the compressive strength, the tensile strength and parameter A increased, and it increased as the karst water pressure, the tunnel excavation height, and parameter B increased. (3) The change trend of the safety thickness with the influencing factors was completely consistent under the two conditions of considering and without the seepage effect, and the safety thickness with considering the seepage force was greater than that without considering the seepage force. Taking the Yunwushan tunnel of Yiwan railway as an example, the critical safety thickness of the water-resistant rock mass was calculated and the calculated value was in good coincidence with the safety thickness adopted in the actual project. The research results are of great significance to prevent the occurrence of high pressure filling karst geological disasters such as water inrush in tunnels.

scholarly journals A Study on the Seepage Flow Characteristics and Disaster-Causing Mechanism of Collapse Column

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Feisheng Feng ◽  
Suping Peng ◽  
Pingjie Fu ◽  
Wenfeng Du ◽  
Dongjing Xu
Keyword(s):  
Water Flow ◽  
Permeability Coefficient ◽  
Water Inrush ◽  
Particle Diameter ◽  
Flow Characteristics ◽  
Seepage Flow ◽  
Fissure Zone ◽  
Experimental Data Processing ◽  
Water Flow Velocity ◽  
Column Collapse

Factors such as the hydrogeological conditions, the lithological characteristics of the columns’ components, and the lithological characteristics and stress conditions of the coal seam roof and floor are interrelated and jointly affect column collapse. In this study, the disaster-causing mechanism of column collapse was studied. Based on the system theory, a collapsed column is divided into the column and the surrounding fissure zone as two subsystems for analysis. And, the permeability coefficient of the broken rock under different conditions was measured by a self-designed equipment. The variations of the permeability coefficient for rock samples with different particle diameters, different axial pressures Pa, and different seepage velocities were further studied. Through phenomena analysis and experimental data processing, it was concluded that, under the same pressure state, smaller particle diameter meant smaller permeability coefficient; with the increase of axial pressure, the permeability coefficient decreased; and the larger the water flow velocity was, the smaller the permeability coefficient became. For particle diameter Φ = 2.5–5 mm or larger, the tiny particles formed by randomly washing and breaking in the water flow blocked some of the channels. For particle diameters smaller than Φ = 2.5–5 mm, the smaller permeability coefficient was attributed to the turbulence resulting from non-Darcy flow. The study on the permeability of the fractured rock mass clarified the mechanism of water inrush from the fissure zone of the collapsed column: the collapsed column itself was impermeable, and the permeability of the fissure zone around the collapsed column was related to the lithological characteristics of the rock within the fissure zone and the sequencing of rock strata. When mining coal in areas with collapsed columns, experiments on collapsed columns and fissure zones are prerequisites. This study has a certain referential value for coal mining in this region.

Study on Safe Thickness of Comparatively Intact Rock Ahead of Karst Tunnel Face

2011 ◽  
Vol 90-93 ◽  
pp. 2456-2459 ◽  
Author(s):  
Jia Qi Guo ◽  
Lian Wei Ren ◽  
Xi Liang Liu
Keyword(s):  
Mechanical Model ◽  
Water Pressure ◽  
Water Inrush ◽  
Intact Rock ◽  
Tensile Fracture ◽  
Karst Tunnel ◽  
Tunnel Face ◽  
Rock Wall ◽  
Safe Thickness ◽  
Tension Strength

Under the effect of water pressure in karst cave before tunnel face, water inrush happens when excavation face enters into the minimal value of safe thickness. Aiming at comparatively intact rock ahead of karst tunnel face, rock wall often appears to be tensile fracture. With some hypotheses, a mechanical model of water inrush for tunnel face instability has been established, furthermore, the analytical expression to calculate safe thickness of rock wall has been given based on the criteria of tension strength through elastical theories. Combined with Maluqing tunnel in Yiwan line, applicability and reliability of formula is discussed.

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