Evolution of Floor Water Inrush from a Structural Fractured Zone with Confined Water

2019 ◽  
Vol 38 (2) ◽  
pp. 252-260 ◽  
Author(s):  
Yanbo Hu ◽  
Wenping Li ◽  
Qiqing Wang ◽  
Shiliang Liu ◽  
Zhenkang Wang
Keyword(s):  
Water Inrush ◽  
Confined Water ◽  
Fractured Zone ◽  
Floor Water Inrush

scholarly journals Failure Characteristics and Confined Permeability of an Inclined Coal Seam Floor in Fluid-Solid Coupling

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jian Sun ◽  
Lianguo Wang ◽  
Guangming Zhao
Keyword(s):  
Stress Concentration ◽  
Coal Seam ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Water Inrush ◽  
Equivalent Stress ◽  
Confined Aquifer ◽  
Confined Water ◽  
Floor Water Inrush ◽  
Failure Depth

Secondary development of FLAC3D software was carried out based on FISH language, and a 3D fluid-solid coupling numerical calculation model was established for an inclined seam mining above a confined aquifer in Taoyuan Coal Mine. A simulation study was implemented on the mining failure depth of an inclined coal seam floor, conducting height of confined water, and the position of workface floor with easy water inrush during advancement of workface. Results indicated that, during the advancement of the inclined coal seam’s workface, obvious equivalent stress concentration areas existed in the floor strata, and the largest equivalent stress concentration area was located at the low region of workface floor. When the inclined coal seam workface advanced to about 80 m, the depth of floor plastic failure zone reached the maximum at approximately 15.0 m, and the maximum failure depth was located at the low region of the workface floor. Before the inclined workface mining, original confined water conducting existed on the top interface of the confined aquifer. The conducting height of the confined water reached the maximum at about 11.0 m when the workface was pushed forward from an open-off cut at about 80 m. Owing to the barrier effect of the “soft-hard-soft” compound water-resistant strata of the workface floor, pore water pressure and its seepage velocity in the floor strata were unchanged after the workface advanced to about 80 m. After the strata parameters at the workface floor were changed, pore water pressure of the confined water could pass through the lower region of the inclined workface floor strata and break through the barrier of the “soft-hard-soft” compound water-resistant strata of the workface floor and into the mining workface, resulting in the inclined coal seam floor water inrush. Results of this study can provide a basis for predicting, preventing, and governing the inclined coal seam floor water inrush above confined aquifer.

Study on Numerical Simulation and Safety Analysis of Floor Water Inrush above Confined Water in Deep Mine

2012 ◽  
Vol 616-618 ◽  
pp. 267-271
Author(s):  
Jian Jun Shen ◽  
Wei Tao Liu ◽  
Yun Juan Liu
Keyword(s):  
Numerical Simulation ◽  
Water Pressure ◽  
Water Inrush ◽  
Continuum Theory ◽  
Imaging Method ◽  
Confined Water ◽  
Floor Rock ◽  
Deep Mine ◽  
Fractured Zone ◽  
Water Bursting

Mine water accident due to the mining above confined water is one of the main factors which affects and threatens safety in the coal production, especially for deep mine. Finding out the mine hydrogeological conditions, deepening the research of water inrush mechanism, and taking the effective safety measures of water bursting prevention, are all the key issues of mining under water pressure safely. Based on fractured rock mass equivalent continuum theory, according to drilling imaging method and water pressure test in borehole, in this paper we focus on discussing the water inrush of the floor rock , determining the floor rock permeability tensor with correction method and simulating the floor inrush problem by coupling stress field and seepage field theory and using anisotropic seepage model with FLAC3D. The results show that, the depth of destroyed floor in normal area and fractured zone in fault are about 30m and 58m respectively. According to empirical equation and numerical simulation, we get the results that the effective protection layer thicknesses are 82m and 115m respectively, and it has presented dangers in fault fractured zone based on the water bursting coefficient method.

The Analysis of the Coal Floor Water Inrush Effected by the Fault

2014 ◽  
Vol 535 ◽  
pp. 626-630
Author(s):  
Yun Xun Zhang ◽  
She Rong Hu ◽  
Ji Chao Peng ◽  
Xue Qing Zhang
Keyword(s):  
Water Pressure ◽  
Water Inrush ◽  
Bottom Layer ◽  
Geological Structure ◽  
Mine Pressure ◽  
Confined Water ◽  
Working Face ◽  
The Face ◽  
Pressure Water ◽  
Floor Water Inrush

Water inrush from coal floor is some kind of complex geology and mining phenomenon. It is the confined water underlying the coal seams breaking the barrier of the bottom layer, and the water runs into the face of mine in emergencies or delayed, causing natural disasters like discharge increases or flooding. According to the previous studies on water inrush, the water inrush is a joint result of geological structure, water pressure, mine pressure, water-resisting floor and mining of working face. The thesis focuses on the influence of geological fault on the water-inrush from coal floor and analyses the controlling effects of fault property and non-water conducted fault activation of water in order to provide a reference or significance for the analysis of water-inrushs genesis mechanism.

Analysis of Factors Influencing Floor Water Inrush in Coal Mines: A Nonlinear Fuzzy Interval Assessment Method

2019 ◽  
Vol 38 (1) ◽  
pp. 81-92 ◽  
Author(s):  
Xintong Wang ◽  
Shucai Li ◽  
Zhenhao Xu ◽  
Peng Lin ◽  
Jie Hu ◽  
...  
Keyword(s):  
Water Inrush ◽  
Coal Mines ◽  
Assessment Method ◽  
Factors Influencing ◽  
Floor Water Inrush ◽  
Fuzzy Interval

scholarly journals Dynamic Monitoring of the Water Flowing Fractured Zone during the Mining Process under a River

2018 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Shuai Chang ◽  
Zhen Yang ◽  
Changfang Guo ◽  
Zhanyuan Ma ◽  
Xiang Wu
Keyword(s):  
Water Flow ◽  
Coal Mine ◽  
Water Inrush ◽  
Unconfined Aquifer ◽  
Coal Extraction ◽  
Fractured Zone ◽  
Transient Electromagnetic ◽  
Geological Conditions ◽  
Longwall Panel ◽  
Flow Mechanisms

The hydrogeological conditions of coal mines in China are quite complex, and water inrush accidents occur frequently with disastrous consequences during coal extraction. Among them, the risk of coal mining under a river is the highest due to the high water transmissivity and lateral charge capacity of the unconfined aquifer under the river. The danger of mining under a river requires the accurate determination of the developmental mechanisms of the water flowing fractured zone (WFFZ) and the water flow mechanisms influenced by the specific geological conditions of a coal mine. This paper first used the transient electromagnetic (TEM) method to monitor the development of the WFFZ and the water flow mechanisms following the mining of a longwall face under a river. The TEM survey results showed that the middle Jurassic coarse sandstone aquifer and the Klzh unconfined aquifer were the main aquifers of the 8101 longwall panel, and the WFFZ reached the aquifers during the mining process. Due to the limited water reserves in the dry season, the downward flowing water mainly came from the lateral recharge in the aquifer. The water inrush mechanisms of the 8101 longwall panel in Selian No.1 Coal mine were analyzed based on the water flow mechanisms of the aquifer and the numerical simulation results. This provides theoretical and technical guidance to enact safety measures for mining beneath aquifers.

On-Site Monitoring of Floor Failure Depth with High Confined Water and Mining Risk Assessment

2013 ◽  
Vol 716 ◽  
pp. 693-698
Author(s):  
Shu Xin Liu ◽  
Chang Wu Liu ◽  
Ya Ming Kang ◽  
Duo Yang
Keyword(s):  
Water Inrush ◽  
Ground Subsidence ◽  
Confined Water ◽  
Mining Technology ◽  
Working Face ◽  
Site Monitoring ◽  
Floor Failure ◽  
Depth Analysis ◽  
Face Length ◽  
Failure Depth

About under-group coal seams mining with the threat of high-pressure ordovician water, conventional mining technology by draining depressurization usually causes environmental issues such as soil erosion and ground subsidence etc.,By using grouting reinforcement technology, this paper changes floor direct charge layer into relatively separatedwater layer in the coal seam and achieves the goals of sealing the water inrush channel, moreover, on the basis of coal floor failure depth analysis and monitoring, the paper evaluates risk of water-inrush from seam floor when face length increases, On this basis, puts forward a reasonable working face length and mining technology, and has abtained good economic and social benefits in practice.

scholarly journals Mechanical Mechanism of Hydraulic Fracturing Effect Caused by Water Inrush in Tunnel Excavation by Blasting

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Quan Zhang ◽  
Jiong Wang ◽  
Longfei Feng
Keyword(s):  
Hydraulic Fracturing ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Water Inrush ◽  
In Situ Stress ◽  
Confined Water ◽  
Shear Damage ◽  
Splitting Factor ◽  
Blasting Excavation

When the deep tunnel is excavated, the pressure of the confined water is relatively high, causing the water inrush to have a hydraulic fracturing effect. The method of theoretical analysis was adopted to study this effect. A mechanical model for fracturing water inrush under blasting excavation conditions was established. The water inrush under this condition is the result of the combined action of static load (water pressure and in situ stress) and dynamic load (explosive stress wave). According to whether the normal stress on the hydraulic crack surface was tensile stress or compressive stress, two types of water inrush were proposed: water inrush caused by tensile-shear damage and water inrush caused by compression-shear damage. These two types of critical water pressures were calculated separately. The relationship between critical water pressure, in situ stress, and blasting disturbance load was given, and a pore water pressure splitting factor was introduced in the calculation process. The theoretically obtained critical water pressure had been verified in the case of water inrush in a deep-buried tunnel. The established theory can guide field practice well.

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