scholarly journals Study on Fracture and Permeability Characteristics of Unloading Rock with High Water Pressure

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zhi-tao Ma ◽  
Yong-qiang Cui ◽  
Ke-yu Lu ◽  
Dai-fu Song ◽  
Ya-chao Yang
Keyword(s):  
Permeability Coefficient ◽  
Failure Modes ◽  
Water Pressure ◽  
Water Inrush ◽  
High Stress ◽  
High Water ◽  
Permeability Characteristics ◽  
Finite Element Software ◽  
Seepage Characteristics ◽  
High Water Pressure

Research on the damage and seepage characteristics of unloading rock with high water pressure can help to further understand the mechanism of water inrush in deep mine floor and prevent water inrush. This paper used the RFPA2D-flow finite element software to study the failure and seepage characteristics of unloading rock with high water pressure and high stress and comparatively analyzed the failure modes and seepage characteristics of unloading rock with and without water pressure. The effects of different water pressure differences on the failure of unloading rock and the law of seepage were investigated by analyzing the change of acoustic emission and permeability coefficient with stress. The results showed that the unloading rock without water pressure was brittle failure, and the initial damage of the unloading model with water pressure was earlier than that of the model without water pressure and showed greater brittleness, and its cracks first break through at the bottom of the sample with higher osmotic pressure. With the increase in unloading, the permeability of rock increased gradually until it appeared an abrupt change. The failure mode and permeability law of the rock with different water pressure differences were basically the same, but the greater the pressure difference, the smaller the effective unloading capacity when the permeability coefficient changes suddenly, and the greater the possibility of water inrush in the rock.

scholarly journals Study on fracture and seepage characteristics of rock mass with high water pressure caused by unloading

2021 ◽  
Vol 303 ◽  
pp. 01055
Author(s):  
Ma Zhi-Tao ◽  
Cui Yong-Qiang ◽  
Yang Ya-Chao ◽  
Song Dai-Fu
Keyword(s):  
Rock Mass ◽  
Pressure Difference ◽  
Water Pressure ◽  
Water Inrush ◽  
High Stress ◽  
High Water ◽  
Deep Mine ◽  
Finite Element Software ◽  
Seepage Characteristics ◽  
High Water Pressure

Research on the damage and seepage characteristics of unloading rock with high water pressure can help to further understand the mechanism of water inrush in deep mine and to take effective measures to prevent water inrush. In this paper, the finite element software RFPA2D-Flow was used to study the failure and seepage characteristics of unloading rock coupled with high water pressure and high stress. The effects of different water pressure on the failure of unloading rock and the law of seepage were investigated. The results show that the form of unloading rock failure without water pressure is brittle; however, the failure form of unloading rock with water pressure is obviously ductile failure, and the fracture is mainly concentrated at the bottom of the rock sample with high water pressure. During unloading, the seepage coefficient of rock increased with the increase of unloading amount until sudden jump occurs, and the failure form and permeability law of the rock with different water pressure were basically the same, but the larger the water pressure difference, the smaller the effective unloading capacity is needed when the permeability coefficient suddenly jumps, this shows that the larger the water pressure difference is, the more likely the rock mass will be damaged by water inrush under unloading condition.

scholarly journals Analysis on Water Inrush Process of Tunnel with Large Buried Depth and High Water Pressure

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 134 ◽  
Author(s):  
Weimin Yang ◽  
Zhongdong Fang ◽  
Hao Wang ◽  
Liping Li ◽  
Shaoshuai Shi ◽  
...  
Keyword(s):  
High Pressure ◽  
Model Test ◽  
Water Pressure ◽  
Water Inrush ◽  
High Water ◽  
Surrounding Rock ◽  
Karst Cave ◽  
Tunnel Excavation ◽  
Pressure Water ◽  
High Water Pressure

In order to explore the catastrophic evolution process for karst cave water inrush in large buried depth and high water pressure tunnels, a model test system was developed, and a similar fluid–solid coupled material was found. A model of the catastrophic evolution of water inrush was developed based on the Xiema Tunnel, and the experimental section was simulated using the finite element method. By analyzing the interaction between groundwater and the surrounding rocks during tunnel excavation, the law of occurrence of water inrush disaster was summarized. The water inrush process of a karst cave containing high-pressure water was divided into three stages: the production of a water flowing fracture, the expansion of the water flowing fracture, and the connection of the water flowing fracture. The main cause of water inrush in karst caves is the penetration and weakening of high-pressure water on the surrounding rock. This effect is becoming more and more obvious as tunnel excavation progresses. The numerical simulation results showed that the outburst prevention thickness of the surrounding rock is 4.5 m, and that of the model test result is 5 m. Thus, the results of the two methods are relatively close to each other. This work is important for studying the impact of groundwater on underground engineering, and it is of great significance to avoid water inrush in tunnels.

scholarly journals Stress Heterogeneity and Slip Weakening of Faults under Various Stress and Slip

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Longjun Dong ◽  
Qiaomu Luo
Keyword(s):  
Slip Surface ◽  
Water Pressure ◽  
High Stress ◽  
Local Stress ◽  
Seismic Source ◽  
High Water ◽  
Fault Slip ◽  
Underground Engineering ◽  
Finite Element Software ◽  
Stress Heterogeneity

The rock mass of deep underground engineering is in the complex geological environment of high stress, high temperature, and high water pressure. In the process of deep mining and underground space development, the fault-slip seismic source may cause engineering accidents with strong destructive capacity. An in-depth study of fault slip characteristics is very important in the engineering disaster prevention and control. In this paper, a slip model was established based on the finite element software ABAQUS. A total of 20 loading ways are set for various stress and slip, which include the possible slip conditions of fast slip, slow slip, and critical state. By comparing the simulation diagrams and collecting the data of representative grid elements on the loading surface and slip surface, the slip characteristics such as stress heterogeneity under different loads are analyzed. The results show that the increase of slip velocity will make the slip unstable, and the local stress and deformation will become irregular. The spatial stress heterogeneity and the resulting local high working rate will lead to the decrease of the friction strength and the slip weakening. These results can provide some useful suggestions for the research of seismic activities caused by fault slip.

Development and Experimental Research on a Formula of Water Inrush Coefficient

2013 ◽  
Vol 448-453 ◽  
pp. 3901-3907
Author(s):  
Gan Tian
Keyword(s):  
High Pressure ◽  
Coal Seam ◽  
Water Resistance ◽  
Water Pressure ◽  
Water Inrush ◽  
High Water ◽  
Residual Pressure ◽  
Simulation Experiments ◽  
Pressure Water ◽  
High Water Pressure

Based on analysis of water inrush coefficients developed and applied in deep coal mining with high water pressure, the author proposes that there are some defects of water inrush coefficients in calculation and application. By simulation experiments on the water resistance properties of the aquiclude in a coal seam floor, the author arrived at the distribution and digital characteristics of residual pressure in the course of high-pressure water rising in the water-resisting floor. The formula for a water inrush coefficient has been further revised.

Permeability coefficient of high fluidity concrete with relation to permeating duration due to high water pressure

2019 ◽  
Author(s):  
Hu Yang ◽  
Cairong Lu ◽  
Weibao Liu ◽  
Guoxing Mei ◽  
Heng Wang ◽  
...  
Keyword(s):  
Permeability Coefficient ◽  
Water Pressure ◽  
High Water ◽  
High Water Pressure

scholarly journals Analysis of Tunnel Water Inrush Considering the Influence of Surrounding Rock Permeability Coefficient by Excavation Disturbance and Ground Stress

2021 ◽  
Vol 11 (8) ◽  
pp. 3645
Author(s):  
Helin Fu ◽  
Pengtao An ◽  
Long Chen ◽  
Guowen Cheng ◽  
Jie Li ◽  
...  
Keyword(s):  
Permeability Coefficient ◽  
Water Pressure ◽  
Water Inrush ◽  
Surrounding Rock ◽  
Water Inflow ◽  
Calculation Error ◽  
External Water Pressure ◽  
Ground Stress ◽  
External Water ◽  
Inflow Prediction

Affected by the coupling of excavation disturbance and ground stress, the heterogeneity of surrounding rock is very common. Presently, treating the permeability coefficient as a fixed value will reduce the prediction accuracy of the water inflow and the external water pressure of the structure, leading to distortion of the prediction results. Aiming at this problem, this paper calculates and analyzes tunnel water inflow when considering the heterogeneity of permeability coefficient of surrounding rock using a theoretical analysis method, and compares with field data, and verifies the rationality of the formula. The research shows that, when the influence of excavation disturbance and ground stress on the permeability coefficient of surrounding rock is ignored, the calculated value of the external water force of the tunnel structure is too small, and the durability and stability of the tunnel are reduced, which is detrimental to the safety of the structure. Considering the heterogeneity of surrounding rock, the calculation error of water inflow can be reduced from 27.3% to 13.2%, which improves the accuracy of water inflow prediction to a certain extent.

scholarly journals Structural modifications of lanthanum silicate oxyapatite exposed to high water pressure

2017 ◽  
Vol 37 (5) ◽  
pp. 2149-2158 ◽  
Author(s):  
Aénor Pons ◽  
Emilie Béchade ◽  
Jenny Jouin ◽  
Maggy Colas ◽  
Pierre-Marie Geffroy ◽  
...  
Keyword(s):  
Water Pressure ◽  
High Water ◽  
Structural Modifications ◽  
Lanthanum Silicate ◽  
High Water Pressure
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