scholarly journals A Water-Rock Coupled Model for Fault Water Inrush: A Case Study in Xiaochang Coal Mine, China

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Luyuan Wu ◽  
Haibo Bai ◽  
Chao Yuan ◽  
Guangming Wu ◽  
Changyu Xu ◽  
...  
Keyword(s):  
Fracture Zone ◽  
Permeability Coefficient ◽  
Axial Stress ◽  
Water Inrush ◽  
Coupled Model ◽  
Fault Zones ◽  
Fractured Zone ◽  
Fault Fracture Zone ◽  
Fractured Sandstone

Water inrush disasters in mining frequently occur under the influence of confined water-bearing fault zones. Therefore, investigating the fault water inrush mechanism is necessary to reduce the number of occurrences of this type of disaster. In fault zones, the rock is highly fractured, and the mechanism of water conduction is complex. In this research, the seepage mechanism of fractured sandstone in fault zones is studied through experiments, and the results indicate that the permeability coefficient of fractured sandstone depends on the axial stress and particle size. The relationship between the permeability coefficient and axial stress was an exponential relationship. Then, a water-rock coupled model is proposed based on the experimental results, which considers the different water flow patterns during water inrush disasters. Finally, a numerical simulation combined with the water-rock coupled model is conducted to investigate the fault water inrush mechanism of a case study, and the results reveal that when water inrush disasters occur during mining, two types of conditions are required. One is that the connection among the fractured zone of the coal seam roof, fault fracture zone, and aquifer fails, and the other is that the connection among the fractured zone of the water inrush prevention pillar, fault fracture zone, and aquifer fails. This study contributes to an increased understanding of the mechanism of water inrush disasters and the design of water inrush prevention pillars.

Evolution of delayed water inrush in fault fracture zone considering time effect

2021 ◽  
Vol 14 (11) ◽  
Author(s):  
Jiwen Bai ◽  
Shaolong Duan ◽  
Rentai Liu ◽  
Lin Xin ◽  
Jiawei Tian ◽  
...  
Keyword(s):  
Fracture Zone ◽  
Water Inrush ◽  
Time Effect ◽  
Fault Fracture Zone

Mechanism of Water Inrush Through Fault Zones Using a Coupled Fluid–solid Numerical Model: A Case Study in the Beiyangzhuang Coal Mine, Northern China

2020 ◽  
Vol 39 (2) ◽  
pp. 380-396
Author(s):  
Wenping Mu ◽  
Xiong Wu ◽  
Ruochen Deng ◽  
Qian Hao ◽  
Cheng Qian
Keyword(s):  
Numerical Model ◽  
Coal Mine ◽  
Water Inrush ◽  
Northern China ◽  
Fault Zones

scholarly journals Failure Mechanism Analysis and Support Technology for Roadway Tunnel in Fault Fracture Zone: A Case Study

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3767
Author(s):  
Kai Wang ◽  
Lianguo Wang ◽  
Bo Ren
Keyword(s):  
Failure Mechanism ◽  
Fracture Zone ◽  
Fractured Rock ◽  
Stress Test ◽  
Deformation Monitoring ◽  
Mechanism Analysis ◽  
Support Design ◽  
Geological Conditions ◽  
Fault Fracture Zone

This paper introduces a case study on the failure mechanism and support design of a roadway tunnel in the fault fracture zone of the 106 mining area in the Yuandian no.2 coal mine. Based on the on-site geological conditions (in-situ stress test, borehole television imaging, and lithological analysis), the failure mechanism of the roadway tunnel in the fault fracture zone was studied. The test results showed that the high tectonic stress, fractured rock, and poor lithology are the primary reasons for the roadway instability. According to the support principles of grouting reinforcement, pre-reinforced support, and rational support range, a new type of combined support technology was proposed, including advanced grouting, grouting bolts, and grouting anchor cables. A 100 m roadway section was selected for field testing using the new support scheme, and detailed deformation monitoring was performed. Monitoring results showed that the roadway deformation under the new support was significantly reduced. During the roadway excavation process, no roof collapse phenomenon occurred, and the safety of roadway excavation was ensured. This successful case provides an important reference for similar roadway projects in the fault fracture zone.

scholarly journals Evaluation of the Risk of Water Gushing（Inrush）in Aquifer of Coal Seam Roof Based on "Three Diagram Method" – a Case Study in Hu Jiahe Coal Mine,china

2020 ◽  
Author(s):  
Enke Hou ◽  
Xing Yao ◽  
Xiaoyang Che
Keyword(s):  
Coal Seam ◽  
Hydraulic Fracture ◽  
Fracture Zone ◽  
Permeability Coefficient ◽  
Comprehensive Evaluation ◽  
Water Inrush ◽  
Research Area ◽  
Index Method ◽  
Diagram Method ◽  
Structure Index

Abstract Coal seam roof inrush phenomenon is common in Jurassic coalfield in China. In order to evaluate accurately the risk of coal seam roof water inrush (CSRWI) it needs to analyze the degree of water rich degree and crack height of strata aquifer. Based on the combined weight-TOPSIS theory, this paper intends to adopt the 8 factors of aquifer thickness, lithological structure index, core adoption rate and permeability coefficient, and TDS from the three aspects of aquifer lithology, hydrology and hydrochemical characteristics. As an evaluation index of the water richness of the aquifer in the Luohe Formation, By using the method of GI method and independent weight method subjective and objective weights influencing aquifer water rich control factors are determined and then weights are coupled by differential maximization theory.Based on GIS spatial analysis technology, an evaluation model of aquifer water rich in coal seam roof aquifer was established and verified by field measured hydrological pore data.Through empirical value calculation of coal seam roof crack height and further refinement of hydraulic fracture zone spread across aquifer floor and combined with aquifer degree of water enrichment and roof cracking degree to carry out comprehensive evaluation of the risk of CSRWI. The most important factors affecting the degree of water enrichment of aquifers are lithological structure index and permeability coefficient, followed by TDS. Compared with water-rich index method, the water-rich degree of aquifer can be effectively determined based on combination weight and TOPSIS method. Moreover, subdivision of roof crack degree indicates that the development height of hydraulic fracture zone in research area is disturbed by aquifer actual disturbance; Risk assessment results indicate that high risk of water inrush lies in southwest side of research area and prevention should be strengthened when mining. This study provides a new idea for evaluating risk zoning of coal seam roof gushing (inrush) water in coal mines of Binchang.

scholarly journals Research on water inrush and mud inrush from water-rich fault fracture zone of deep tunnel in mountainous area

2020 ◽  
Vol 782 ◽  
pp. 042057
Author(s):  
Yanhui Guo ◽  
Mengxiang Ma ◽  
Biyu Rao ◽  
Jincai Lu ◽  
Jin He
Keyword(s):  
Fracture Zone ◽  
Water Inrush ◽  
Mountainous Area ◽  
Deep Tunnel ◽  
Fault Fracture Zone

scholarly journals Comparative Analysis of Roadway Reinforcement Effects Based on Fluid-Solid Coupling in the Fractured Zone of Water-Rich Fault

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Jihua Zhang ◽  
Yun Dong ◽  
Yadong Chen ◽  
Yang Jiang ◽  
Huasheng Sun ◽  
...  
Keyword(s):  
Fault Zone ◽  
Permeability Coefficient ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Water Inrush ◽  
Surrounding Rock ◽  
Fractured Zone ◽  
Transient Electromagnetic ◽  
Working Face ◽  
Fissure Water

Water inrush is a common geological disaster during the roadway excavation process in the broken zone of water-rich faults. In this paper, the 15107 mining roadway built by Yuxing coal mine in such a fault zone was used as a case study to determine the water content of the surrounding rocks and a fault zone using the transient electromagnetic method (TEM). Also, the mechanics characteristics of such rocks in both saturated and unsaturated states were analyzed, a computational model for fluid-solid coupling in the water-rich fault fracture zone was established, and the permeability coefficient of the rocks under both shield support and bolt-grouting support was compared, along with analyzing the changes in pore pressure, fissure water velocity, and characteristics of deformation in the surrounding rocks. The numerical simulation results show that the fault range has an influence of about 20 m, which causes the forms of permeability coefficient to change like a hump. The permeability coefficient in the fractured zone is the largest, and the mutation rate at the fault plane is faster. Bolting not only reduces the permeability coefficient of the surrounding rock that is 1/10 of the beam support but also prevents the roof fissure water inrushing the roadway and the surrounding rock of the floor, while also causing the pore-water pressure to decrease, even reduce to zero, in front of the working face and floor. The flow velocity of the fissure water can be decreased by bolting, which can effectively control the deformation of the surrounding rock by 38.7%∼65% compared with the shield support. The practice results show that this method can effectively recover the cracks surrounding the mining roadway and stop gushing water. Concurrently, it successfully controls deformation of the surrounding rocks in the fault zone, thus ensuring stability of the roadway and facilitating safer mining production.

scholarly journals Experimental Study on Seepage Properties of Postpeak Fractured Rocks under Cyclic Loading-Unloading Confining Stress and Axial Stress

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xiaobo Zhang ◽  
Zuhao Xia ◽  
Chi Yao ◽  
Jianhua Yang ◽  
Mingdong Yang
Keyword(s):  
Cyclic Loading ◽  
Permeability Coefficient ◽  
Fractured Rocks ◽  
Axial Stress ◽  
Rock Fracture ◽  
Complex Loading ◽  
Seepage Flow ◽  
Confining Stress ◽  
Fractured Sandstone ◽  
Seepage Properties

Excavation in rock masses always encounters safety problems from rock fracture seepage in water-rich areas, which needs to be paid much attention, especially for fractured rocks under complicated stress state. For this reason, the permeability of fractured sandstone and granite is experimentally investigated under cyclic loading-unloading confining stress and axial stress. The variation of permeability coefficient and seepage flow with increasing and decreasing the confining stress and axial stress are comprehensively analyzed. Results show that the changing patterns of permeability with loading-unloading cycles of confining stress for both fractured sandstone and granite are similar. The permeability is most sensitive to the initial loading-unloading stages. After several loading-unloading cycles, the confining stress has little effect on permeability. The seepage flow decreases as the confining stress is unloaded to the same level in the loading process, indicating a hysteresis effect on the recovery of seepage capacity. The seepage properties under cyclic loading-unloading the axial stress are quite different from those under the confining stress. The permeability of fractured sandstone is most sensitive to the first cycle of loading-unloading of axial stress. The irrecoverable shear slide between fractures under the axial stress causes dilatancy or contraction, which makes the permeability coefficient to consecutively decrease at the subsequent cycles. The permeability of granite first decreases during the first loading of axial stress, while this trend is disordered at the subsequent stages no matter loading or unloading the axial stress. This is because of the accumulation of breakage fragments between fractures, which further disturbs the seepage flow. These findings may be useful for further understanding the seepage properties of fractured granite and sandstone under complex loading-unloading history.

Water-inrush Risk through Fault Zones with Multiple Karst Aquifers Underlying the Coal Floor: A Case Study in the Liuzhuang Coal Mine, Southern China

2021 ◽  
Author(s):  
Jian Zhang ◽  
Liangliang Guo ◽  
Wenping Mu ◽  
Shouqiang Liu ◽  
Dexing Zhao
Keyword(s):  
Coal Mine ◽  
Southern China ◽  
Water Inrush ◽  
Fault Zones ◽  
Karst Aquifers

Groundwater flow simulation and its application in GaoSong ore field, China

2018 ◽  
Vol 10 (2) ◽  
pp. 276-284 ◽  
Author(s):  
Gang Chen ◽  
Shiguang Xu ◽  
Chunxue Liu ◽  
Lei Lu ◽  
Liang Guo
Keyword(s):  
Numerical Model ◽  
Flow Field ◽  
Groundwater Flow ◽  
Mine Water ◽  
Permeability Coefficient ◽  
Water Inrush ◽  
Seepage Field ◽  
Groundwater Seepage ◽  
Calculation Results ◽  
Groundwater Flow Field

Abstract Mine water inrush is one of the important factors threatening safe production in mines. The accurate understanding of the mine groundwater flow field can effectively reduce the hazards of mine water inrush. Numerical simulation is an important method to study the groundwater flow field. This paper numerically simulates the groundwater seepage field in the GaoSong ore field. In order to ensure the accuracy of the numerical model, the research team completed 3,724 field fissure measurements in the study area. The fracture measurement results were analyzed using the GEOFRAC method and the whole-area fracture network data were generated. On this basis, the rock mass permeability coefficient tensor of the aquifer in the study area was calculated. The tensor calculation results are used in the numerical model of groundwater flow. After calculation, the obtained numerical model can better represent the groundwater seepage field in the study area. In addition, we designed three different numerical models for calculation, mainly to explore the influence of the tensor assignment of permeability coefficient on the calculation results of water yield of the mine. The results showed that irrational fathom tensor assignment would cause a significant deviation in calculation results.

Soil-water inrush induced shield tunnel lining damage and its stabilization: A case study

2020 ◽  
Vol 97 ◽  
pp. 103290 ◽  
Author(s):  
Linchong Huang ◽  
Jianjun Ma ◽  
Mingfeng Lei ◽  
Linghui Liu ◽  
Yuexiang Lin ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Inrush ◽  
Tunnel Lining ◽  
Shield Tunnel
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