Impacts of confining pressure and safety thickness on water and mud inrush in weathered granite

Liu, Jinquan; Chen, Weizhong; Deng, Zhi-Ping; Liu, Taogen; Dong, Jicheng

doi:10.1080/1064119x.2018.1563253

Cited by 10 publications

(5 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Pan et al (2019) studied the water inrush mechanisms of underground tunnels that are near a water-filled karst cavern. Liu et al (2020) performed a series of experiments based on a self-designed testing system and non-Darcy testing method to study the water and mud inrush evolution. Zhang, Jiang, et al (2014) simulated the entire process of crack formation, the propagation of buried faults, and the evolution of water inrush channel under high-pressure water in a coal mine floor, and revealed the lagging water inrush mechanism of the coal floor in a confined water body.…”

Section: Introductionmentioning

confidence: 99%

The variable-mass seepage law of broken porous rock: an experimental study

Wang

Fan

et al. 2020

Geomatics, Natural Hazards and Risk

View full text Add to dashboard Cite

Induced by tunnel excavation, the particles constantly shift in broken porous rock of faults until failure occurs, which provides channels for water inrush. Therefore, it is essential to investigate the particle migration of broken porous rock. Thus, a visual experimental system of particle migration was developed independently. Further study on the mass loss evolution of broken porous rock induced by seepage failure was performed using physical model tests, and the effect of the grain gradation of broken porous rock was also analyzed. According to the composition and lost characteristics of the samples, the samples were divided into dense-suspension structure and void-skeleton structure. The results indicated that the mass loss of the particles decreased with the increase in the gradation coefficient when the sample had a dense-suspension structure, while there was no significant change in the lost quality with the increase of gradation coefficient when the sample had a void-skeleton structure. Moreover, the time required for water inrush decreased with the increase in the gradation coefficient, which is because the higher the content of the fine particles is, the lower the permeability of the sample. Sample settlement is positively correlated with the lost quality of particles.

show abstract

Section: Introductionmentioning

confidence: 99%

The variable-mass seepage law of broken porous rock: an experimental study

Wang

Fan

et al. 2020

Geomatics, Natural Hazards and Risk

View full text Add to dashboard Cite

show abstract

“…Where ðP xy + P W sin θÞ is the resultant force projected by P xy and P W in the axis direction of the outburst prevention rock mass and ðπD 2 Þ/ð4 sin θÞ is the contact area between the outburst prevention rock mass and the fault zone. Substitute equation (7) into equation (8), let n = ð2μð B + L sin θÞÞ/BL, and the expression of the minimum safety thickness is…”

Section: Calculation Of Safe Thickness For Tunnelmentioning

confidence: 99%

“…According to the research of Yang et al [6] and Liu et al [7], the insufficient safe thickness of tunnel outburst prevention is one of the most important engineering factors caus-ing water and mud inrush. Therefore, it is of great significance for the safe construction of tunnels to study the safety thickness of tunnel outburst prevention in the fault fracture zone.…”

Section: Introductionmentioning

confidence: 99%

Research on the Safety Thickness of Tunnel Outburst Prevention in Water-Rich Fault Fracture Zone Based on Janssen’s Theory

Zhong

Zhou

2022

Geofluids

View full text Add to dashboard Cite

In the construction of tunnel in water-rich fault fracture zone, when the thickness of outburst prevention is insufficient, it is very easy to cause water and mud inrush engineering accident. Therefore, it is very necessary to study the safety thickness of outburst prevention for this type of tunnel. In this paper, the expression of in situ stress in water-rich fault fracture zone is derived based on Janssen’s theory. Two mechanical models of outburst prevention rock mass are established, and according to the shear balance theory, the calculation formula for the safe thickness of outburst prevention is determined and the parameter sensitivity analysis is carried out. Finally, it is verified by engineering examples and numerical simulation. The results show that: (1) the calculation formula of outburst prevention thickness proposed in this paper is more perfect and shows good prediction effect for deep- and shallow-buried tunnels; (2) the greater the angle α between tunnel axis and fault zone and the dip θ of fault fracture zone, the smaller the critical safety thickness of outburst prevention and the safer it is for tunnel construction; (3) when the fault fracture zone inclines inward relative to the tunnel face, the gravity of the rock mass in the fault zone will lead to an increase in the safety thickness of outburst prevention, and reinforcement measures should be taken during actual construction.

show abstract

“…Ma et al [16] experimentally investigated the impacts of particle transfer on the porosity and permeability of karst collapse pillar under varying pore pressure, particle size mixture and compaction level. Liu et al [17,18] further explored the variation characteristics of fluidized grain concentration and Reynolds number as the advancing of seepage-erosion process. However, previous experimental researches mainly concentrated on the variation of flow parameters (porosity, permeability, Reynolds number) as the advancing of water-sand inrush, the evolution characteristics of seepage-erosion process was not adequately comprehended.…”

Section: Introductionmentioning

confidence: 99%

Experiment Study of the Failure Mechanism and Evolution Characteristics of Water–Sand Inrush Geo-Hazards

Liu

Бо

2020

Applied Sciences

View full text Add to dashboard Cite

Water–sand inrush disasters are frequently encountered during underground engineering construction in karst terrain. The objective of this paper is to study the failure mechanism and evolution characteristics of water–sand inrush caused by the instability of filling medium in karst cavity, as well as the impacts of soil compactness, hydraulic pressure and confining pressure on the instability process. In response to this purpose, a stress-controlled seepage test apparatus in consideration of particle loss was designed, and a series of seepage tests were performed correspondingly. The test results indicate that: (1) Based on the nonlinear feature analysis of water-outflow pattern, the water–sand inrush process can be divided into the “slow flow” stage, “transition flow” stage and “pipe flow” stage by Transition Point I, II. (2) The decreasing soil compactness and increasing hydraulic pressure both exponentially facilitate the seepage-erosion process by increasing the particle-erosion ability; the increasing confining pressure extends the “slow flow” stage and shortens the duration of the “transition flow” stage, ultimately advancing the occurrence of the “pipe flow” stage; the existence of critical hydraulic pressure for the seepage-erosion progress is confirmed, the occurrence of the “pipe flow” stage is significantly advanced once the hydraulic pressure over the critical value. (3) The particle loss caused by the seepage-erosion process is the internal mechanism of water–sand inrush, the variation characteristics of water-outflow pattern are crucial external manifestations correspondingly. Therefore, with the monitoring of water-outflow pattern variation tendency as indicators, the critical status of water–sand inrush can be near-real-time identified, which offers experimental foundation for the early warning and forecast of the occurrence of water–sand inrush.

show abstract

Impacts of confining pressure and safety thickness on water and mud inrush in weathered granite

Cited by 10 publications

References 24 publications

The variable-mass seepage law of broken porous rock: an experimental study

The variable-mass seepage law of broken porous rock: an experimental study

Research on the Safety Thickness of Tunnel Outburst Prevention in Water-Rich Fault Fracture Zone Based on Janssen’s Theory

Experiment Study of the Failure Mechanism and Evolution Characteristics of Water–Sand Inrush Geo-Hazards

Contact Info

Product

Resources

About