scholarly journals Stability Analysis of Steel Lining at Pressure Diversion Tunnel Collapse Zone during Operating Period

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Ming Xiao ◽  
Chen Zhao
Keyword(s):  
Large Scale ◽  
Water Pressure ◽  
Concrete Lining ◽  
Seepage Field ◽  
Diversion Tunnel ◽  
Steel Lining ◽  
Internal Water ◽  
External Water Pressure ◽  
External Water ◽  
The Stability

At the collapse zone, the effects of the thickness of the consolidation grouting layer and the water pressure on the steel lining are vital to the stability of steel-lined pressure diversion tunnels. In this paper, a joint element and the load-sharing ratio of the consolidation layer are introduced to investigate the joint load-bearing characteristics of the steel lining and the consolidation layer and to determine a suitable consolidation layer thickness; a coupling method for simulating the hydromechanical interaction of the reinforced concrete lining is adopted to investigate the effect of internal water exosmosis on the seepage field at the collapse zone and to determine the external water pressure on the steel lining. In the case of a steel-lined pressure diversion tunnel, a numerical simulation is implemented to analyse the effect of the thickness of the consolidation layer and the distribution of the seepage field under the influence of internal water exosmosis. The results show that a 10 m thick consolidation layer and the adopted antiseepage measures ensure the stability of the steel lining at the collapse zone under internal and external water pressure. These research results provide a reference for the design of treatment measures for large-scale collapses in steel-lined pressure tunnels.

Experimental Study on the Carrying Capacity of Lining Structure of Hydraulic Tunnel

2011 ◽  
Vol 361-363 ◽  
pp. 1593-1597
Author(s):  
Wei Shen ◽  
Shi Lang Xu
Keyword(s):  
Large Scale ◽  
Water Pressure ◽  
Concrete Lining ◽  
Outer Side ◽  
Total Water ◽  
Deformation Properties ◽  
Lining Structure ◽  
External Water Pressure ◽  
External Water ◽  
Stress And Deformation

In this paper, a large-scale indoor model test with water pressure is conducted in order to investigate the stress and deformation properties of reinforced concrete lining structures with circular cross-sections.Under internal water pressure, the water pressure carried by lining structure is about 20%~40% of total water pressure before cracking and less than 30% after cracking.Under external water pressure, without drainage of outer side of lining, the water pressure carried by lining structure is only less than 40% of total water pressure.

Research on Effect of Grouting Circle on Seepage Field of Subsea Tunnel

2012 ◽  
Vol 204-208 ◽  
pp. 1409-1412
Author(s):  
You Wang ◽  
Xing Hua Wang ◽  
Jun Ru Chen
Keyword(s):  
Water Pressure ◽  
Jiaozhou Bay ◽  
Water Quantity ◽  
Seepage Field ◽  
Calculation Results ◽  
Free Drainage ◽  
External Water Pressure ◽  
Subsea Tunnel ◽  
External Water

According to a real project of Jiaozhou Bay subsea tunnel, the effect of grouting circle on the seepage field was discussed. The calculation results showed that the principle of "to block mainly, to emit limitedly" should be taken in the waterproofing and drainage of subsea tunnel. If the grouting circle effect was used on the condition of the same effect of water plugging, the thinner the thickness of grouting circle and the smaller permeability coefficient of grouting circle required. The role of grouting circle was that decreasing the gushing water quantity by means of blocking the seepage paths of groundwater, so as to achieve a smaller discharge could significantly reduce the external water pressure of lining. When the tunnel gushing water quantity was equal to the control discharge, it was considered as free drainage and the lining could not bear the water pressure.

The Simulation and Sensitivity Analysis of S-Lay Installation in Deep Water

2012 ◽  
Vol 249-250 ◽  
pp. 59-64
Author(s):  
Li Ping Sun ◽  
De Jun Wang ◽  
Shang Mao Ai ◽  
Xiang Zheng
Keyword(s):  
Sensitivity Analysis ◽  
Deep Water ◽  
Water Pressure ◽  
Bending Moment ◽  
Mechanical Analysis ◽  
Axial Tension ◽  
External Water Pressure ◽  
External Water ◽  
The Stability ◽  
Large Work

Pipelines being laying is subjected the high external water pressure, axial tension and bending moment, influencing the large deformation and the stability of pipelines. It is a key problem about the pipeline deformation and stress analysis under installation. The paper is focused on the analysis of the S-Lay method in deep water, modeling the deepwater S-lay installations considering interactions among the pipeline and stinger and the barge, which make the simulations more realistic. The large work of the paper issues the sensitivity analysis in the installation procedure, several examples are presented to calculate the pipeline configuration and mechanical analysis for different laying water depth, pipe diameter, thickness of wall and concrete weighted coating layer and stinger radius. Some results are presented as well.

Experimental Investigation of a Large-Scale Composite Riser Tube Under External Pressure

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Guillermo Ramirez ◽  
Michael D. Engelhardt
Keyword(s):  
Carbon Fiber ◽  
Test Specimen ◽  
Large Scale ◽  
Water Pressure ◽  
External Pressure ◽  
Collapse Pressure ◽  
Filament Wound ◽  
External Water Pressure ◽  
External Water ◽  
Carbon Fiber Epoxy

A collapse pressure test was conducted on a full-scale diameter prototype composite offshore drilling riser. The test specimen was a carbon fiber-epoxy filament-wound tube, approximately 56.4 cm outside diameter and 3.05 cm wall thickness. The tube was subjected to external water pressure up to collapse. The purpose of the test was to confirm the external pressure capacity of the specimen and to provide a basis for verification and calibration of analytical estimates of the collapse pressure of large scale carbon fiber tubes. The specimen was instrumented with strain gauges on both the outside and inside walls of the tube. This paper describes the test specimen and presents key results of the test.

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.

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.

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