scholarly journals Corrigendum to “Effects of Initial Porosity and Water Pressure on Seepage-Erosion Properties of Water Inrush in Completely Weathered Granite”

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-1
Author(s):  
Jinquan Liu ◽  
Weizhong Chen ◽  
Taogen Liu ◽  
Jianxin Yu ◽  
Jingliang Dong ◽  
...  
Keyword(s):  
Water Pressure ◽  
Water Inrush ◽  
Initial Porosity ◽  
Seepage Erosion ◽  
Weathered Granite ◽  
Erosion Properties ◽  
Completely Weathered Granite

scholarly journals Effects of Initial Porosity and Water Pressure on Seepage-Erosion Properties of Water Inrush in Completely Weathered Granite

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jinquan Liu ◽  
Weizhong Chen ◽  
Taogen Liu ◽  
Jianxin Yu ◽  
Jingliang Dong ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Water Pressure ◽  
Water Inrush ◽  
Water Inflow ◽  
Initial Porosity ◽  
Effective Control ◽  
Flow Properties ◽  
Particle Transfer ◽  
Weathered Granite ◽  
Completely Weathered Granite

In order to investigate the water inrush mechanism in completely weathered granite, a large-scale triaxial testing system is designed and manufactured, which can induce the mass transfer and monitor the flow properties. Using this system, the effects of water pressure and initial porosity on the mass transfer and flow properties were determined, and the relative critical conditions for water inrush were proposed. The results indicate that (1) the particle transfer could cause an increase in porosity, permeability, and water inflow, which is the essential reason for water inrush in completely weathered granite. (2) Due to the effect of particle transfer, the flow properties may change from a Darcy to a non-Darcy flow, which is a key signal for water inrush. (3) With the increase of water pressure, the mass transfer, permeability, and water inflow increased gradually, and a critical value (p=0.6 MPa) that caused the water inrush was obtained. Furthermore, with the decrease of initial porosity, the mass transfer and flow properties were suppressed rapidly, and a critical porosity (0.23) to anti-inrush was observed. The results obtained can provide an important reference for understanding the mechanism, forecasting the risk, and taking the effective control measures for water inrush.

Nonlinear seepage–erosion coupled water inrush model for completely weathered granite

2017 ◽  
Vol 36 (4) ◽  
pp. 484-493 ◽  
Author(s):  
Jinquan Liu ◽  
Weizhong Chen ◽  
Diansen Yang ◽  
Jingqiang Yuan ◽  
Xiaofei Li ◽  
...  
Keyword(s):  
Water Inrush ◽  
Seepage Erosion ◽  
Weathered Granite ◽  
Completely Weathered Granite

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 A Global Optimization-Based Method for the Prediction of Water Inrush Hazard from Mining Floor

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1618 ◽  
Author(s):  
Dan Ma ◽  
Hongyu Duan ◽  
Xin Cai ◽  
Zhenhua Li ◽  
Qiang Li ◽  
...  
Keyword(s):  
Global Optimization ◽  
Water Pressure ◽  
Water Inrush ◽  
Hybrid Genetic Algorithm ◽  
Function Parameter ◽  
Support Vector ◽  
Suitable Model ◽  
Svm Model ◽  
Highly Nonlinear ◽  
Mine Floor

Water inrush hazards can be effectively reduced by a reasonable and accurate soft-measuring method on the water inrush quantity from the mine floor. This is quite important for safe mining. However, there is a highly nonlinear relationship between the water outburst from coal seam floors and geological structure, hydrogeology, aquifer, water pressure, water-resisting strata, mining damage, fault and other factors. Therefore, it is difficult to establish a suitable model by traditional methods to forecast the water inrush quantity from the mine floor. Modeling methods developed in other fields can provide adequate models for rock behavior on water inrush. In this study, a new forecast system, which is based on a hybrid genetic algorithm (GA) with the support vector machine (SVM) algorithm, a model structure and the related parameters are proposed simultaneously on water inrush prediction. With the advantages of powerful global optimization functions, implicit parallelism and high stability of the GA, the penalty coefficient, insensitivity coefficient and kernel function parameter of the SVM model are determined as approximately optimal automatically in the spatial dimension. All of these characteristics greatly improve the accuracy and usable range of the SVM model. Testing results show that GA has a useful ability in finding optimal parameters of a SVM model. The performance of the GA optimized SVM (GA-SVM) is superior to the SVM model. The GA-SVM enables the prediction of water inrush and provides a promising solution to the predictive problem for relevant industries.

scholarly journals Numerical Analysis of the Mud Inflow Model of Fractured Rock Mass Based on Particle Flow

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Yongjian Pan ◽  
Huajun Wang ◽  
Yanlin Zhao ◽  
Qiang Liu ◽  
Shilin Luo
Keyword(s):  
Rock Mass ◽  
Pressure Gradient ◽  
Flow Direction ◽  
Fractured Rock ◽  
Water Pressure ◽  
Water Inrush ◽  
Quadratic Function ◽  
Particle Flow ◽  
Fractured Rock Mass ◽  
Particle Flows

Water inrush and mud outburst are one of the crucial engineering disasters commonly encountered during the construction of many railways and tunnels in karst areas. In this paper, based on fluid dynamics theory and discrete element method, we established a fractured rock mass mud inflow model using particle flow PFC3D numerical software, simulated the whole process of fractured rock mass mud inflow, and discussed the effect of particle size and flow velocity on the change of pressure gradient. The numerical simulation results show that the movement of particles at the corner of the wall when the water pressure is first applied occurs similar to the vortex phenomenon, with the running time increases, the flow direction of particles changes, the vortex phenomenon disappears, and the flow direction of particles at the corner points to the fracture; in the initial stage, the slope of the particle flows rate curves increases in time, and the quadratic function is used for fitting. After the percolation velocity of particles reaches stability, the slope of the curve remains constant, and the primary function is used for fitting; the particle flow rate and pressure gradient are influenced by a variety of factors, and they approximately satisfy the exponential function of an “S” curve.

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 Hydrological Characteristics of Ordovician Karst Top in a Deep Region and Evaluation of Its Threat to Coal Mining: A Case Study for the Weibei Coalfield in Shaanxi Province, China

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Tao Li ◽  
Jiarui Zhang ◽  
Ying Gao ◽  
Xinqi Cao ◽  
Hongyang Liu ◽  
...  
Keyword(s):  
Coal Mining ◽  
North China ◽  
Water Pressure ◽  
Water Inrush ◽  
Drainage Water ◽  
Shaanxi Province ◽  
Water Drainage ◽  
Mining Areas ◽  
Hydrogeological Characteristics ◽  
In Situ Experiments

Widely distributed in North China, Ordovician karst is characterized by having high thickness, nonuniform aquosity, and significant water pressure-bearing properties. Deep mining in North China is threatened by associated water hazards; hence, research on the hydrogeological characteristics of deep Ordovician karst is needed. In this study, the Weibei coalfield in Shaanxi Province, China, was selected as the study area, especially mines in the Hancheng and Chenghe mining areas. In situ experiments, including water pumping, water drainage, water injecting and water pressure, and laboratory experiments, were conducted to study the hydrogeological characteristics of the Ordovician karst top in the study area. A comprehensive analysis was conducted on controlling factors for the development of the Ordovician karst top in the study area, and a method for evaluating the water inrush risk in coal mining areas based on karst hydrogeological characteristics was proposed. The research results indicated that the Ordovician karst top in the study area was characterized by heterogeneity, vertical zonation, and partially filled properties, which were mainly controlled by two factors: sedimentation and tectonism. The hydrogeological conditions of the Ordovician karst could be divided into three types: nonfilled and nonsignificant tectonism, filled and nonsignificant tectonism, and significant tectonism. Among them, the filled and nonsignificant tectonism type Ordovician karst top type had a filling thickness of 20 m. Based on karst hydrogeological characteristics, the methods were proposed to evaluate the water inrush risk in the coal mining floor. The practical tests verified the methods.

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