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Infiltration
Published in Amithirigala Widhanelage Jayawardena, Fluid Mechanics, Hydraulics, Hydrology and Water Resources for Civil Engineers, 2021
Amithirigala Widhanelage Jayawardena
Soil hydraulic conductivity determines the capacity of the soil to conduct moisture. It is also sometimes referred to as the soil permeability. For partially saturated soils, the hydraulic conductivity depends on the degree of saturation (or the moisture content). At saturation, the hydraulic conductivity attains its maximum value asymptotically. The saturated hydraulic conductivity can be measured either in situ by field permeameters or in the laboratory using soil samples. In the latter case, the falling head permeameter and the constant head permeameter methods are commonly used. It is difficult to measure the unsaturated hydraulic conductivity and often various methods of estimation using probability concepts are used. A simple relationship used by Campbell (1974), Clapp and Hornberger (1978) is of the form K=Ks[θθs]B
Methods of Analysis of Contaminant Migration in Barrier Materials
Published in Donald L. Wise, Debra J. Trantolo, Edward J. Cichon, Hilary I. Inyang, Ulrich Stottmeister, Remediation Engineering of Contaminated Soils, 2000
Hilary I. Inyang, John L. Daniels, Calvin C. Chien
Constant Versus Falling-Head Permeameter. Constant-head permeameters are not commonly used in fine-grained soil permeability measurements. The relative imperviousness of barrier materials implies that permeation times would be excessive. The advantage of the falling-head setup is that small flows can be measured easily (24). Furthermore, flow can be enhanced by the use of air pressure to increase the head on the tested sample. It was found that the constant-head permeability test values had a tendency to be slightly higher than falling-head values for the same clayey soil (29).
Laboratory Investigations
Published in F.G.H. Blyth, M. H. de Freitas, A Geology for Engineers, 2017
F.G.H. Blyth, M. H. de Freitas
Permeability is a measure of the velocity of fluid flow through a porous sample under the hydraulic head operating within the sample; the sample is housed in a permeameter. That shown in Fig. 11.11 is typical of many used for testing sands; silts and clays require slightly different apparatus. Permeability is normally calculated from the following relationship: K = Q/iA
Experimental and numerical study on drainage characteristics of drainage pipes with porous foam filters
Published in European Journal of Environmental and Civil Engineering, 2021
The relevant parameters of polyurethane foam can be found in Table 2. The reticulated polyurethane foam of 40 ppi (40 pores per inch) and open-cell polyurethane foam were selected, and both of them were 15 mm in thickness; 40 ppi means that there were 40 pores in the length of 25.4 mm, and the average diameter of the pores was 0.635 mm regardless of the thickness of the pore wall. However, if the thickness was taken into account, the average diameter of the hole would be about 0.5 mm. The equivalent pore size of open-cell polyurethane foam was determined by dry sieve method (ASTM 4751-16, 2012). The permeability coefficient of polyurethane foam was measured by the vertical permeameter. This measuring method is similar to the permeability-measurement of geotextile according to Darcy’s law (ASTM D4491/D4491M-17, 2017).
Performance of pervious concrete pavement under various raining conditions
Published in Road Materials and Pavement Design, 2019
Maryam Saaly, Mohammad Mostafa Hedayat, Amir Golroo
After a thorough literature review, a PCP slab was placed on AUT campus, which was applied as a sidewalk. The mix design and placement of this slab were presented elsewhere (name deleted to maintain the integrity of the review process). In order to measure the permeability rate of PCP, an apparatus called a permeameter was designed and developed. A compliment digital counter tool was attached to it to be able to rigorously capture the elapsed time of a certain falling head of water. Having applied this apparatus, the permeability rate of PCP was measured at eight points within the slab at three time intervals between two consecutive measurements in three replicates for four months. Some pre-processing tests were conducted on the captured data to ensure that there were no outliers and noises present. After that, data was explored and various descriptive statistics were derived. Then, data were analysed and the effect of various raining conditions was investigated on the permeability rate through the development of degradation models. Finally, the models were validated using the n-fold data-split technique. Figure 1 illustrates the research methodology.
Effects of hydration on physical properties and rock microstructure of shale oil reservoir in the Triassic Chang 7 Member of Southern Ordos Basin
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Pengfei Zhao, Xiangyu Fan, Qiangui Zhang, Mingming Zhang, Bowei Yao
According to Boyle’s law, the porosity of rock can be measured by the double chamber method (Luquot and Gouze 2009). A VINCI HEP-P porosity tester was used in the experiment. Darcy’s law reflects the ability of a fluid to pass through rocks (Sheng, Javadpour, and Su 2019). In the experiment, the permeability of the cores was measured by the VINCI Gasperm permeameter. The minimum pressure of mercury entering the pore is inversely proportional to the size of the pore. According to this characteristic, mercury porosimetry could accurately measure the distribution of different size pores in rock (Labani et al. 2013; Wang et al. 2019). The pore distribution of the rock was measured by the Poremaster-60 high-pressure mercury instrument.