Numerical simulation of abnormal roof water-inrush mechanism in mining under unconsolidated aquifer based on overburden dynamic damage

2021 ◽  
pp. 106005
Author(s):  
Luwang Chen ◽  
Qinghua Ou ◽  
Zhihong Peng ◽  
Yingxin Wang ◽  
Yifei Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Water Inrush ◽  
Dynamic Damage

Numerical Simulation of Blasting-Induced Damage in Grouting Curtain of Sandstone Aquifer for Vertical Shaft

2015 ◽  
Vol 723 ◽  
pp. 271-278
Author(s):  
Yu Liang Zhou ◽  
Dong Feng Yuan ◽  
Jun Zheng ◽  
Hua Wang
Keyword(s):  
Numerical Simulation ◽  
Prevention And Control ◽  
Damage Zone ◽  
Surrounding Rock ◽  
Damage Effect ◽  
Vertical Shaft ◽  
Control Methods ◽  
Sandstone Aquifer ◽  
And Control ◽  
Dynamic Damage

To provide a theoretical basis for water prevention and control methods and reasonable supporting techniques for vertical shaft, and to ensure the shaft construction to pass the sandstone aquifer safely and rapidly, numerical simulation using dynamic damage constitutive model, which was a user-defined constitutive modules in FLAC3D, a lagrangian analysis code in three dimensions, has been applied to investigate the dynamic damage effect in the surrounding rock of the grouting curtain near the driving working face for vertical shaft excavated by blasting. The results indicate that the distribution of the damage zone in the surrounding rock of the shaft, which decreases the effective thickness of the grouting curtain, was like a ellip-se, and that the depth of the damage zone in the surrounding rock of the shaft grouting curtain is fewer than that of the driving face floor. It can be concluded that the centre part of the driving face floor, especially the cutting hole zones, and the shaft wall in the greater horizontal stress side are the " key parts " for shaft water prevention and control methods.

scholarly journals A Mechanical Model of the Overlying Rock Masses in Undersea Coal Mining and a Stress-Seepage Coupling Numerical Simulation

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Jie Fang ◽  
Lei Tian ◽  
Yanyan Cai ◽  
Zhiguo Cao ◽  
Jinhao Wen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Coal Mining ◽  
Water Inrush ◽  
Mining Area ◽  
Analysis Model ◽  
Fractured Zones ◽  
Working Face ◽  
Seam Mining ◽  
Overlying Strata

The water inrush of a working face is the main hidden danger to the safe mining of underwater coal seams. It is known that the development of water-flowing fractured zones in overlying strata is the basic path which causes water inrushes in working faces. In the engineering background of the underwater mining in the Longkou Mining Area, the analysis model and judgment method of crack propagation were created on the basis of the Mohr–Coulomb criterion. Fish language was used to couple the extension model into the FLAC3d software, in order to simulate the mining process of the underwater coal seam, as well as to analyze the initiation evolutionary characteristics and seepage laws of the fractured zones in the overlying strata during the advancing processes of the working face. The results showed that, during the coal seam mining process, the mining fractured zones which had been caused by the compression-shear and tension-shear were mainly concentrated in the overlying strata of the working face. Also, the open-off cut and mining working face were the key sections of the water inrush in the rock mass. The condition of the water disaster was the formation of a water inrush channel. The possible water inrush channels in underwater coal mining are mainly composed of water-flowing fractured zones which are formed during the excavation processes. The numerical simulation results were validated through the practical engineering of field observations on the height of water-flowing fractured zone, which displayed a favorable adaptability.

Numerical simulation of water inrush in fault zone considering seepage paths

2020 ◽  
Vol 104 (2) ◽  
pp. 1763-1779
Author(s):  
Haitao Yu ◽  
Shuyun Zhu ◽  
Huadong Xie ◽  
Junhua Hou
Keyword(s):  
Numerical Simulation ◽  
Fault Zone ◽  
Water Inrush

scholarly journals Numerical Simulation Study of Variable-Mass Permeation of the Broken Rock Mass under Different Cementation Degrees

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Chong Li ◽  
Banghua Yao ◽  
Qingqing Ma
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Mass Loss ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Water Inrush ◽  
Variable Mass ◽  
Erosion Effect ◽  
Porosity And Permeability ◽  
Rock Specimens

In order to analyze variable-mass permeation characteristics of broken rock mass under different cementation conditions and reveal the water inrush mechanism of geological structures containing broken rock masses like karst collapse pillars (KCPs) in the coal mine, the EDEM-FLUENT coupling simulation system was used to implement a numerical simulation study of variable-mass permeation of broken rock mass under different cementation conditions and time-dependent change laws of parameters like porosity, permeability, and mass loss rate of broken rock specimens under the erosion effect were obtained. Study results show that (1) permeability change of broken rock specimens under the particle migration effect can be divided into three phases, namely, the slow-changing seepage phase, sudden-changing seepage phase, and steady seepage phase. (2) Specimen fillings continuously migrate and run off under the water erosion effect, porosity and permeability rapidly increase and then tend to be stable, and the mass loss rate firstly rapidly increases and then gradually decreases. (3) Cementation degree has an important effect on permeability of broken rock mass. As cementing force of the specimen is enhanced, its maximum mass loss rate, mass loss, porosity, and permeability all continuously decrease. The study approach and results not only help enhance coal mining operations safety by better understanding KCP water inrush risks. It can also be extended to other engineering applications such as backfill paste piping and tailing dam erosion.

North China Lower Coal Surrounding Rock Failure Characteristics Study Based on FLAC3D and Fiber Bragg Grating

2013 ◽  
Vol 353-356 ◽  
pp. 1057-1062
Author(s):  
Zai Bin Liu
Keyword(s):  
Numerical Simulation ◽  
Fiber Bragg Grating ◽  
North China ◽  
Water Inrush ◽  
Rock Failure ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Bragg Grating ◽  
Failure Characteristics ◽  
Test Face

In order to study north China type coal field lower coal surrounding rock failure characteristics, a numerical model was built based on the numerical simulation software FLAC3D. Water inrush information was monitored during mining process based on optical fiber Bragg grating sensor technology. Lower coal surrounding failure characteristics were studied according to numerical simulation and monitoring results. This study show that the first weighting distance of the test face is from 35m to 40m and the periodic weighting step distance is from 10m to 20m. Coal floor can be divided to three areas which are increased stress area, decreased stress area and recovery stress area. Coal roof failure scope is like a composition of two saddle-shaped zones along trend and tendency directions. Normal failure depth of the test face floor is from 10m to 12.5m, and it can reach 22.5m near open-off cut and stop line. The research can explain the reason of the test faces water inrush accident and can direct lower coal mine water control work.

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.

Fluid-Solid Coupling Numerical Simulation Analysis of Impermeable Rock Mining Seam Floor Failure

2014 ◽  
Vol 1010-1012 ◽  
pp. 1527-1530
Author(s):  
Chun Jie Song ◽  
Cheng Fan
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Water Inrush ◽  
Three Dimensional ◽  
Deep Understanding ◽  
Simulation Method ◽  
Relevant Information ◽  
Simulation Software ◽  
Pressurized Water ◽  
Floor Failure

Based on a deep understanding of FLAC 3D numerical simulation software and the solid-liquid coupling theory and calculation method, this paper established a mining three-dimensional mechanical model under the pressurized water .Using the numerical simulation method, this paper systematically analysis deformation Laws of stress distribution of mining floor, bottom stress, its plastic zone and floor failure depth. By analyzing water inrush flow-solid coupling seepage problem under the conditions of coal mining, and compares with relevant information, verify the rationality of the existing theories and engineering measures, provide a theoretical basis for seeking security and economic exploitation of technical measures.

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