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.

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.

Discussion on Structure Design of Shaft Lining Built in Porous Rocky Aquifer with High Water Pressure

2012 ◽  
Vol 446-449 ◽  
pp. 2196-2201
Author(s):  
Xiao Min Zhou ◽  
Bing Deng ◽  
Cheng Xuan Ma
Keyword(s):  
Water Pressure ◽  
High Water ◽  
Structure Design ◽  
Surrounding Rock ◽  
Porous Rock ◽  
Traditional Design ◽  
Universal Feature ◽  
Pressure Water ◽  
Shaft Lining ◽  
High Water Pressure

Firstly based on the practical problem of lining thickness built in porous rock aquifer with high water pressure, this paper introduce the mechanical and stable seepage model, and design formula of shaft lining named Baoshen; Secondly, the character of load and parameters in the “Baoshen” formula are studied, compared with the “Lame” formula and the original heavy earth field , which shows good universal feature to cover several traditional design methods. Thirdly, the principals of interaction among high pressure water, lining and surrounding rock are revealed by figure and discuss on inequality inequation; With a newly application example, the practical usage are introduced and newly viewpoints are opened to designers with material promotion, arrangement of re-bar or bolt, structure optimum etc.

scholarly journals Effect of Wetting-Drying Cycle on the Deformation and Seepage Behaviors of Rock Masses around a Tunnel

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Qingzhen Guo ◽  
Haijian Su ◽  
Hongwen Jing ◽  
Wenxin Zhu
Keyword(s):  
Rock Mass ◽  
Principal Stress ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Water Inrush ◽  
Surrounding Rock ◽  
Tunnel Excavation ◽  
Cycle Number ◽  
Simulation Results

Water inrush caused by the wetting-drying cycle is a difficult problem in tunnel excavation. To investigate the effect of the wetting-drying cycle on the stability of the tunnel surrounding rock, physical experiments and numerical simulations regarding the process of tunnel excavation with different wetting-drying cycle numbers were performed in this study. The evolutions of stress, displacement, and pore water pressure were analyzed. With the increase in cycle number, the pore water pressure, vertical stress, and top-bottom approach of the tunnel surrounding rock increase gradually. And the increasing process could be divided into three stages: slightly increasing stage, slowly increasing stage, and sharply increasing stage, respectively. The failure process of the surrounding rock under the wetting-drying cycle gradually occurs from the roof to side wall, while the baseplate changes slightly. The simulation results showed that the maximum principal stress in the surrounding rock mass of the tunnel increases, while the minimum principal stress decreases. Furthermore, the displacement of the rock mass decreases gradually with the increasing distance from the tunnel surface. By comparing the simulation results with the experimental results, well consistency is shown. The results in this study can provide helpful references for the safe excavation and scientific design of a tunnel under the wetting-drying cycle.

Model test of the tunnel subjected to high water pressure in Jinping Second Cascade Hydropower Station, China

2011 ◽  
Vol 54 (S1) ◽  
pp. 192-198 ◽  
Author(s):  
JianXiu Wang ◽  
Bo Feng ◽  
LiSheng Hu ◽  
PuZhuo Tian ◽  
DongChang Sui ◽  
...  
Keyword(s):  
Model Test ◽  
Water Pressure ◽  
High Water ◽  
Hydropower Station ◽  
High Water Pressure

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 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 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.

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