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Hydraulic experiments for determination of in-situ hydraulic conductivity of submerged sediments.

Lee BJ, Lee JH, Yoon H, Lee E - Sci Rep (2015)

Bottom Line: The system allows water to move upward through the porous media filled in the permeameter chamber driven into sediments at water-sediment interface.Darcy flux and hydraulic gradient can be measured using the system, and the VHC can be determined from the relationship between them using Darcy's law.Results from the evaluation tests indicate that the permeameter proposed in this study can be used to measure VHC of saturated sandy sediments at water-sediment interface in stream and marine environment with high accuracy.

View Article: PubMed Central - PubMed

Affiliation: Groundwater Department, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350, Republic of Korea.

ABSTRACT
A new type of in-situ hydraulic permeameter was developed to determine vertical hydraulic conductivity (VHC) of saturated sediments from hydraulic experiments using Darcy's law. The system allows water to move upward through the porous media filled in the permeameter chamber driven into sediments at water-sediment interface. Darcy flux and hydraulic gradient can be measured using the system, and the VHC can be determined from the relationship between them using Darcy's law. Evaluations in laboratory and in field conditions were performed to see if the proposed permeameter give reliable and valid measures of the VHC even where the vertical flow at water-sediment interface and fluctuation of water stage exist without reducing the accuracy of the derived VHC. Results from the evaluation tests indicate that the permeameter proposed in this study can be used to measure VHC of saturated sandy sediments at water-sediment interface in stream and marine environment with high accuracy.

No MeSH data available.


Related in: MedlinePlus

Tidal data at the Sungsan tidal station near the Bangdu Bay for September 13, 2013, and the black rectangular points indicate the times and tidal heights of three tests which took place from low-to-high tide period.
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f3: Tidal data at the Sungsan tidal station near the Bangdu Bay for September 13, 2013, and the black rectangular points indicate the times and tidal heights of three tests which took place from low-to-high tide period.

Mentions: Three tests were conducted during neap tide in September 13, 2013 to measure the hydraulic conductivities of the sediments of the bay at different tide levels as shown in Figure 3. Experiments were performed with an interval of about 1 h from low to high tide, and the tidal height of each test was 113, 133, and 156 cm at 11:40 am, 12:30 pm, and 13:30 pm, respectively. The system was deployed at the position approximately 30 m seaward of mean tide. The chamber of the permeameter used in the field test was 13.4 cm in diameter and 40 cm in length. Two ports with one-touch fittings were installed in the side of the chamber, at the upper and the lower positions, with 20 cm apart from each other, and located at 10 cm from the double ends of the chamber. The cylindrical pipe for measuring volumetric flow rate was 4.8 cm in diameter and 150 cm long. These two components of the permeameter were made with steel and inter-connected with flexible polyurethane tubing with inner diameter of 0.4 cm and outer diameter of 0.6 cm. A series of measurements for volumetric flow rates and hydraulic gradients was performed at the same point where the chamber of the system was deployed into sediments. The volumetric flow rates were calculated from water level recorded at 5 s intervals with a pressure transducer, and head differences were measured using manometers. Because of waves, the Δd was set approximately at a depth of 10, 20, 30, and 40 cm below the sea water level during the each test.


Hydraulic experiments for determination of in-situ hydraulic conductivity of submerged sediments.

Lee BJ, Lee JH, Yoon H, Lee E - Sci Rep (2015)

Tidal data at the Sungsan tidal station near the Bangdu Bay for September 13, 2013, and the black rectangular points indicate the times and tidal heights of three tests which took place from low-to-high tide period.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4300508&req=5

f3: Tidal data at the Sungsan tidal station near the Bangdu Bay for September 13, 2013, and the black rectangular points indicate the times and tidal heights of three tests which took place from low-to-high tide period.
Mentions: Three tests were conducted during neap tide in September 13, 2013 to measure the hydraulic conductivities of the sediments of the bay at different tide levels as shown in Figure 3. Experiments were performed with an interval of about 1 h from low to high tide, and the tidal height of each test was 113, 133, and 156 cm at 11:40 am, 12:30 pm, and 13:30 pm, respectively. The system was deployed at the position approximately 30 m seaward of mean tide. The chamber of the permeameter used in the field test was 13.4 cm in diameter and 40 cm in length. Two ports with one-touch fittings were installed in the side of the chamber, at the upper and the lower positions, with 20 cm apart from each other, and located at 10 cm from the double ends of the chamber. The cylindrical pipe for measuring volumetric flow rate was 4.8 cm in diameter and 150 cm long. These two components of the permeameter were made with steel and inter-connected with flexible polyurethane tubing with inner diameter of 0.4 cm and outer diameter of 0.6 cm. A series of measurements for volumetric flow rates and hydraulic gradients was performed at the same point where the chamber of the system was deployed into sediments. The volumetric flow rates were calculated from water level recorded at 5 s intervals with a pressure transducer, and head differences were measured using manometers. Because of waves, the Δd was set approximately at a depth of 10, 20, 30, and 40 cm below the sea water level during the each test.

Bottom Line: The system allows water to move upward through the porous media filled in the permeameter chamber driven into sediments at water-sediment interface.Darcy flux and hydraulic gradient can be measured using the system, and the VHC can be determined from the relationship between them using Darcy's law.Results from the evaluation tests indicate that the permeameter proposed in this study can be used to measure VHC of saturated sandy sediments at water-sediment interface in stream and marine environment with high accuracy.

View Article: PubMed Central - PubMed

Affiliation: Groundwater Department, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350, Republic of Korea.

ABSTRACT
A new type of in-situ hydraulic permeameter was developed to determine vertical hydraulic conductivity (VHC) of saturated sediments from hydraulic experiments using Darcy's law. The system allows water to move upward through the porous media filled in the permeameter chamber driven into sediments at water-sediment interface. Darcy flux and hydraulic gradient can be measured using the system, and the VHC can be determined from the relationship between them using Darcy's law. Evaluations in laboratory and in field conditions were performed to see if the proposed permeameter give reliable and valid measures of the VHC even where the vertical flow at water-sediment interface and fluctuation of water stage exist without reducing the accuracy of the derived VHC. Results from the evaluation tests indicate that the permeameter proposed in this study can be used to measure VHC of saturated sandy sediments at water-sediment interface in stream and marine environment with high accuracy.

No MeSH data available.


Related in: MedlinePlus