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 Comparative Analysis of Roadway Reinforcement Effects Based on Fluid-Solid Coupling in the Fractured Zone of Water-Rich Fault

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Jihua Zhang ◽  
Yun Dong ◽  
Yadong Chen ◽  
Yang Jiang ◽  
Huasheng Sun ◽  
...  
Keyword(s):  
Fault Zone ◽  
Permeability Coefficient ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Water Inrush ◽  
Surrounding Rock ◽  
Fractured Zone ◽  
Transient Electromagnetic ◽  
Working Face ◽  
Fissure Water

Water inrush is a common geological disaster during the roadway excavation process in the broken zone of water-rich faults. In this paper, the 15107 mining roadway built by Yuxing coal mine in such a fault zone was used as a case study to determine the water content of the surrounding rocks and a fault zone using the transient electromagnetic method (TEM). Also, the mechanics characteristics of such rocks in both saturated and unsaturated states were analyzed, a computational model for fluid-solid coupling in the water-rich fault fracture zone was established, and the permeability coefficient of the rocks under both shield support and bolt-grouting support was compared, along with analyzing the changes in pore pressure, fissure water velocity, and characteristics of deformation in the surrounding rocks. The numerical simulation results show that the fault range has an influence of about 20 m, which causes the forms of permeability coefficient to change like a hump. The permeability coefficient in the fractured zone is the largest, and the mutation rate at the fault plane is faster. Bolting not only reduces the permeability coefficient of the surrounding rock that is 1/10 of the beam support but also prevents the roof fissure water inrushing the roadway and the surrounding rock of the floor, while also causing the pore-water pressure to decrease, even reduce to zero, in front of the working face and floor. The flow velocity of the fissure water can be decreased by bolting, which can effectively control the deformation of the surrounding rock by 38.7%∼65% compared with the shield support. The practice results show that this method can effectively recover the cracks surrounding the mining roadway and stop gushing water. Concurrently, it successfully controls deformation of the surrounding rocks in the fault zone, thus ensuring stability of the roadway and facilitating safer mining production.

Predicting external water pressure and cracking of a tunnel lining by measuring water inflow rate

2018 ◽  
Vol 71 ◽  
pp. 115-125 ◽  
Author(s):  
Yuqi Tan ◽  
John V. Smith ◽  
Chun-Qing Li ◽  
Matthew Currell ◽  
Yufei Wu
Keyword(s):  
Water Pressure ◽  
Tunnel Lining ◽  
Water Inflow ◽  
Inflow Rate ◽  
External Water Pressure ◽  
External Water

Control of arterial pressure in aquatic sea snakes

1983 ◽  
Vol 244 (1) ◽  
pp. R66-R73 ◽  
Author(s):  
H. B. Lillywhite ◽  
F. H. Pough
Keyword(s):  
Arterial Pressure ◽  
Blood Volume ◽  
Water Pressure ◽  
Cardiovascular Responses ◽  
Physiological Regulation ◽  
Sea Snakes ◽  
Head Up Tilt ◽  
External Water Pressure ◽  
External Water ◽  
Head Level

Cardiovascular responses to head-up tilt, acutely graded hemorrhage, and pharmacologic stimulation by principal autonomic drugs were studied in four species of marine snakes, principally Aipysurus laevis (family Hydrophiidae). Arterial pressure varied inversely with tilt angle and blood volume deficit in conscious snakes outside of water, indicating that physiological regulation was poor or lacking. Calculated arterial pressures at head level typically diminished to zero in A. laevis tilted to angles greater than or equal to 30 degrees. Arterial pressure (corrected for external water pressure) did not change when these snakes were tilted in seawater. Changes of arterial pressure induced by tilt, blood loss, or autonomic drugs elicited reflex adjustments in heart activity, but the magnitude of these responses was less than that observed in terrestrial species of snake. It is concluded that baroreflexes are present but comparatively ineffective in sea snakes. Snakes tolerated large losses of blood volume, and extravascular fluids were absorbed into the circulation during hemorrhage; both hemorrhage and estimated hemodilution volumes exceeded 100% of the initial blood volume in Acalyptophis peronii. Thus, in marine snakes major fluid shifts between nonvascular and vascular compartments significantly compensate hypovolemia but, because of minor autonomic adjustments, do not result in a well-regulated arterial pressure.

scholarly journals A multicentered comparison of measurements obtained with microtip and external water pressure transducers

2005 ◽  
Vol 17 (4) ◽  
pp. 400-406 ◽  
Author(s):  
Andrew F. Hundley ◽  
Morton B. Brown ◽  
Linda Brubaker ◽  
Geoffrey W. Cundiff ◽  
Karl Kreder ◽  
...  
Keyword(s):  
Water Pressure ◽  
Pressure Transducers ◽  
External Water Pressure ◽  
External Water

scholarly journals Instruments and Methods High Pressure Coupling for Pipe in Deep Water Filled Bore Holes

1963 ◽  
Vol 4 (36) ◽  
pp. 809-812
Author(s):  
R. L. Shreve
Keyword(s):  
High Pressure ◽  
Water Pressure ◽  
The Other ◽  
Internal Diameter ◽  
External Diameter ◽  
Synthetic Rubber ◽  
External Water Pressure ◽  
External Water ◽  
One Year ◽  
Aluminum Pipe

AbstractIn August 1961 an aluminum pipe (3.5 cm. internal diameter, 4.2 cm. external diameter) having 92 specially modified socket couplings (5.0 cm. external diameter) sealed with a quick-polymerizing synthetic rubber was sunk 226 m. in a vertical water-filled bore hole in Blue Glacier, Washington. U.S.A. The geometry of threads and mating surfaces of pipe and coupling was designed to cause increasing external water pressure to tighten the seal. One joint at a depth of 66 m. immediately developed an extremely slow leak (probably because of faulty cleaning), but the other 91 joints apparently were sound, as the pipe was free of water to a depth of at least 157 m. when resurveyed after one year.

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.

Interstitial and intravascular pressures in conscious dogs during head-out water immersion

1989 ◽  
Vol 257 (2) ◽  
pp. R358-R364
Author(s):  
K. Miki ◽  
M. R. Klocke ◽  
S. K. Hong ◽  
J. A. Krasney
Keyword(s):  
Hydrostatic Pressure ◽  
Interstitial Fluid ◽  
Water Pressure ◽  
Water Immersion ◽  
Ulnar Artery ◽  
Conscious Dogs ◽  
External Reference ◽  
External Water Pressure ◽  
External Water ◽  
Peripheral Arterial

Water immersion (WI) causes an increase in plasma volume in humans and dogs. To determine the mechanism for this fluid movement, the transmission of external water hydrostatic pressure to the interstitial and vascular compartments was studied in six conscious dogs. Systemic arterial, central venous, peripheral arterial (ulnar artery) and venous (cephalic vein), pleural, intra-abdominal, and interstitial fluid hydrostatic (by Guyton's capsule and wick catheter method) pressures and external reference water pressure were measured at three different levels of WI: 1) extremities only, 2) midchest, and 3) midcervical levels at 37 degrees C. There was a significant linear relationship between interstitial fluid hydrostatic pressure (X) and external water pressure (Y): (Y = 0.86X + 1.4, r = 0.93 by Guyton's capsule; Y = 0.85X + 2.4, r = 0.93 by wick catheter. However, vascular pressures did not change when dogs were immersed at the level of the extremities. These pressures increased only during WI at the midchest and midcervical levels. Therefore the pressure gradient that develops between the interstitial and intravascular compartments is probably the major reason for the transcapillary fluid shift during WI.

Vibration of ring-stiffened circular cylinders under external water pressure

1996 ◽  
Vol 60 (6) ◽  
pp. 1013-1019 ◽  
Author(s):  
C.T.F. Ross ◽  
P. Haynes ◽  
W.D. Richards
Keyword(s):  
Water Pressure ◽  
Circular Cylinders ◽  
External Water Pressure ◽  
External Water
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