scholarly journals The Slotted Tube Overlay Geotextile in Tailing Pond Radial Seepage Test Model and Analysis of the Permeation Characteristics

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Chun-bo Yang ◽  
Yuan Wang ◽  
Lin-bing Wang ◽  
Jing-qi Huang ◽  
Qing-wen Li ◽  
...  
Keyword(s):  
Permeability Coefficient ◽  
Radial Flow ◽  
Drainage System ◽  
Test Model ◽  
Two Dimensional ◽  
Permeability Characteristics ◽  
Permeability Coefficients ◽  
Water Head ◽  
Flow Test ◽  
Before And After

Slotted tube drainage system plays an important role in reducing the wetting line of tailing dam. In the past studies, the permeability coefficient of geotextile was measured separately based on one-dimensional test, and the permeability characteristics of the whole system of the slotted tube overlay geotextile were rarely studied. Firstly, a set of radial flow test equipment for infiltration system of the slotted tube overlay geotextile is developed in this study. Then, with the aid of the test device, a two-dimensional radial flow test is conducted to investigate the drainage system of the slotted tube overlay geotextile before and after blocking by tailing sands, with considering different water head difference and the number of geotextile layers. By the two-dimensional radial flow test, it can be concluded that (1) the permeability coefficients of the slotted tube overlay geotextile before and after blocking all have a slight upward trend with the increase of water head difference; (2) with increasing the number of geotextile layers, the permeability coefficients before and after blocking increase first and then decrease, which approaching its minimum value at about two layers; (3) under the seepage pressure, some particles might attach to or stay in geotextile. Therefore, the permeability coefficient of the slotted tube overlay geotextile after blocking is significantly smaller than that before blocking. This study offers the insight to the further research on the permeation characteristics of the slotted tube overlay geotextile system.

scholarly journals Experimental Analysis on Permeability Characteristics of Iron Tailings

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Deqing Gan ◽  
Xi Yang ◽  
Yunpeng Zhang
Keyword(s):  
Particle Size ◽  
Permeability Coefficient ◽  
Void Ratio ◽  
Average Particle Size ◽  
Average Particle ◽  
Fine Content ◽  
Permeability Characteristics ◽  
Permeability Coefficients ◽  
Effective Particle ◽  
The Relationship

The permeability characteristics of iron tailings are one of the important factors affecting the stability of the tailings dam. The permeability properties of undisturbed iron tailings and disturbed iron tailings were analyzed from various aspects such as FC value, gradation, particle size, specific surface area, and interparticle void ratio with water head test in laboratory. The results show that the permeability coefficients of undisturbed iron tailings and disturbed iron tailings are affected by the fine particles content (FC). The threshold of fine content is about 40%. The traditional formulas for calculating the permeability coefficient are applied. But the results are inaccurate. The relationship between permeability coefficient of the iron tailings (undisturbed iron tailings and disturbed iron tailings) and the nonuniform coefficient (Cu), the curvature coefficient (Cc), the average particle size, the weighted average particle size, the specific surface area, and the skeleton void ratio (es) is nonlinear. It is difficult to characterize the change of permeability coefficient when the fine content is large. However, the relationship between permeability coefficient of the iron tailings (undisturbed iron tailings and disturbed iron tailings) and the effective particle size and silt particles void ratio (ef) is linear. A formula was developed for the determination of permeability coefficient of iron tailings by analyzing the effective particle size and silt particles void ratio. And it is more accurate. The permeability coefficients of disturbed samples are slightly larger than the permeability coefficients of undisturbed sample. This is due to the destruction of the sedimentary structure of the tailings and increasing e. Maybe the R in the new formula is affected by the structure of iron tailings. This requires further research.

scholarly journals The model and simulation of low impact development of the sponge airport, China

2019 ◽  
Vol 20 (2) ◽  
pp. 383-394 ◽  
Author(s):  
Jing Peng ◽  
Jiayi Ouyang ◽  
Lei Yu ◽  
Xinchen Wu
Keyword(s):  
Flood Control ◽  
Low Impact Development ◽  
Water Environment ◽  
Drainage System ◽  
Practical Significance ◽  
International Airport ◽  
Model And Simulation ◽  
Impervious Area ◽  
Before And After ◽  
Airport Runway

Abstract Recently urban waterlogging problems have become more and more serious, and the construction of an airport runway makes the impervious area of the airport high, which leads to the deterioration of the water environment and frequent waterlogging disasters. It is of great significance to design and construct the sponge airport with low impact development (LID) facilities. In this paper, we take catchment N1 of Beijing Daxing International Airport as a case study. The LID facilities are designed and the runoff process of a heavy rainfall in catchment N1 is simulated before and after the implementation of LID facilities. The results show that the total amount of surface runoff, the number of overflow junctions and full-flow conduits of the rainwater drainage system in catchment N1 of Beijing Daxing International Airport are significantly reduced after the implementation of the LID facilities. Therefore, the application of LID facilities has greatly improved the ability of the airport to remove rainwater and effectively alleviated the risk of waterlogging in the airport flight area. This study provides theoretical support for airport designers and managers to solve flood control and rainwater drainage problems and has vital practical significance.

scholarly journals The impact of agriculture drainage reconstruction on ground water recession close to the subgrade

2015 ◽  
Vol 10 (3) ◽  
pp. 230-238 ◽  
Author(s):  
Vilimantas Vaičiukynas ◽  
Saulius Vaikasas ◽  
Henrikas Sivilevičius ◽  
Audrius Grinys
Keyword(s):  
Agricultural Land ◽  
Drainage System ◽  
Hydraulic Permeability ◽  
Road Maintenance ◽  
Permeability Characteristics ◽  
The Road ◽  
The Impact ◽  
Good Drainage ◽  
Important Design ◽  
Local Road

Good drainage is the most important design consideration for a road, both to miniaturize road maintenance costs and maximize the time the road is operational. The lack of good drainage lead to the structural damages and costly repairs. Many of roads are built in intensively drained agricultural land. The effective way to drain subgrades is reconstruction of existing agricultural drainage. The impact of cross-subsurface drainage system on water level fluctuation was measured using Plane geofiltration mathematical model, one of 3D geofiltration modelling programs. The hydraulic permeability characteristics were determined in field of Pikeliai, close to local road in Kėdainiai district, Lithuania. This object is composed of clay and loamy soils. Subsurface cross drains trenches spacing of 20 m, 30 m and 40 m were simulated. The hydraulic permeability of cross drain trenches and lateral trenches modelled was from 0.006 m/a day to 6 m/a day. The simulation of cross drains trenches showed that the most effective distance between them are 20 m. The highest water depression occurs when the permeability of cross drain trenches and lateral trenches is ~ 6 m/day, at the distance of 20 m. The water recession is 20 cm lower compared to the drainage systems without cross drains trenches. By installing cross drains trenches every 30 m, water recession is 10 cm lower when the trench permeability is about 6 m/day. When increasing the distance between the cross drains up to 40 m their influence disappears.

scholarly journals The Influence of Bedding Planes and Permeability Coefficient on Fracture Propagation of Horizontal Wells in Stratification Shale Reservoirs

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Yuepeng Wang ◽  
Xiangjun Liu ◽  
Lixi Liang ◽  
Jian Xiong
Keyword(s):  
Permeability Coefficient ◽  
In Situ Stress ◽  
Stress Difference ◽  
Strength Parameters ◽  
Breakdown Pressure ◽  
Permeability Coefficients ◽  
Bedding Planes ◽  
Initiation Pressure ◽  
Shale Reservoirs

The complexity of hydraulic fractures (HF) significantly affects the success of reservoir reconstruction. The existence of a bedding plane (BP) in shale impacts the extension of a fracture. For shale reservoirs, in order to investigate the interaction mechanisms of HF and BPs under the action of coupled stress-flow, we simulate the processes of hydraulic fracturing under different conditions, such as the stress difference, permeability coefficients, BP angles, BP spacing, and BP mechanical properties using the rock failure process analysis code (RFPA2D-Flow). Simulation results showed that HF spread outward around the borehole, while the permeability coefficient is uniformly distributed at the model without a BP or stress difference. The HF of the formation without a BP presented a pinnate distribution pattern, and the main direction of the extension is affected by both the ground stress and the permeability coefficient. When there is no stress difference in the model, the fracture extends along the direction of the larger permeability coefficient. In this study, the in situ stress has a greater influence on the extension direction of the main fracture when using the model with stress differences of 6 MPa. As the BP angle increases, the propagation of fractures gradually deviates from the BP direction. The initiation pressure and total breakdown pressure of the models at low permeability coefficients are higher than those under high permeability coefficients. In addition, the initiation pressure and total breakdown pressure of the models are also different. The larger the BP spacing, the higher the compressive strength of the BP, and a larger reduction ratio (the ratio of the strength parameters of the BP to the strength parameters of the matrix) leads to a smaller impact of the BP on fracture initiation and propagation. The elastic modulus has no effect on the failure mode of the model. When HF make contact with the BP, they tend to extend along the BP. Under the same in situ stress condition, the presence of a BP makes the morphology of HF more complex during the process of propagation, which makes it easier to achieve the purpose of stimulated reservoir volume (SRV) fracturing and increased production.

Oxygen and carbon dioxide permeability of subcutaneous pockets

1962 ◽  
Vol 202 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Hugh D. Van Liew
Keyword(s):  
Carbon Dioxide ◽  
Blood Flow ◽  
Surface Area ◽  
Uptake Rate ◽  
Permeability Coefficient ◽  
Exchange Coefficient ◽  
Adjacent Tissue ◽  
Permeability Coefficients ◽  
Tissue Tension

Uptake rate of a gas from a rat's subcutaneous gas pocket was divided by the surface area and by the apparent pocket-to-tissue tension difference to yield an exchange coefficient, K'. Values in (ml x 10–4)/(min cm2 atm) were O2, 6.6; CO2, 150; and N2, 2. Blood flow in adjacent tissue appeared to have little influence on uptakes of O2 and CO2, since the K'co2:K'o2 ratio indicated that the uptakes were governed by diffusion alone, and drastic alteration of blood flow (death of the animal) decreased K'o2 by only 10%. In contrast, blood flow apparently affected N2 uptake. Because O2 and CO2 uptakes were not blood flow limited, K'o2 and K'co2 are estimates of true permeability coefficients; the calculated permeability coefficient for N2 is 3.3 (ml x 10–4)/(min cm2 atm). Comparison shows the pocket surface to be 1/50–1/150 as effective for O2 transfer as the lung. Finally, corrections are calculated for pocket-to-tissue pO2 and pCO2 differences in gas pockets used for tissue tonometry.

Accuracy of Two-Dimensional Echocardiographic Planimetry of the Mitral Valve Area before and after Balloon Valvuloplasty

Cardiology ◽  
1998 ◽  
Vol 90 (3) ◽  
pp. 227-230 ◽  
Author(s):  
Avinoam Shiran ◽  
Steven A. Goldstein ◽  
Samer Ellahham ◽  
Gary S. Mintz ◽  
Augusto D. Pichard ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Balloon Valvuloplasty ◽  
Two Dimensional ◽  
Mitral Valve Area ◽  
Before And After ◽  
Valve Area

Study on Original Coal Seam Permeability Coefficient

2011 ◽  
Vol 361-363 ◽  
pp. 179-182
Author(s):  
Zi Wen Dong ◽  
Qing Jie Qi ◽  
Nan Hu ◽  
Chang Fu Xu ◽  
Hui Niu
Keyword(s):  
Coal Seam ◽  
Water Flow ◽  
Coal Mine ◽  
Permeability Coefficient ◽  
Gas Flow ◽  
Radial Flow ◽  
Gas Permeability ◽  
Coal Seam Gas ◽  
Flow Method

In the case of gas radial flowing in layer-though boring, use the method of draining water gathering gas measured the Gas flow of borehole that there is water flow out from drilling Sometimes,the coal seam gas permeability coefficient is calculated using"Radial Flow Method"and"Optimizing Method,found out the range of 5-3 original coal seam Hongmiao coal mine permeability coefficient is0.007~0.008 m2/(MPa2·d).

Proteinaceous Bubbles and Nano Particle Flows in Microchannel

2004 ◽  
Author(s):  
Jung-Yeul Jung ◽  
Ki-Taek Byun ◽  
Jae-Ho Hong ◽  
Ho-Young Kwak
Keyword(s):  
Flow Rate ◽  
Flow Behavior ◽  
Average Diameter ◽  
Scattering Method ◽  
Nano Particle ◽  
Test Results ◽  
Particle Flows ◽  
Flow Test ◽  
Before And After ◽  
Flow Through

Proteinaceous bubbles of 185 nm in average diameter were synthesized by a sonochemical treatment of bovine serum albumin in aqueous solution and the nanoparticles (TiO2) solution was made by ultrasonic irradiation. To study the macroscopic flow behavior associated with the changes in the state of microparticles, a flow test of these solutions in microchannels was done. Also the size distributions of the proteinaceous bubbles in solution before and after the flow test were measured by a light scattering method. Test results show that the air-filled proteinaceous bubbles in solution adjust their size to reduce the shear stress encountered in the flow through the microchannel. On the other hand, the flow rate of the solution with nanoparticles suspensions becomes smaller than that of deionized water above the flow rate of 6 cm3/min in the microchannel with a dimension of 100×150 μm2.

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