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Pore water pressure

About: Pore water pressure is a research topic. Over the lifetime, 11455 publications have been published within this topic receiving 247670 citations. The topic is also known as: pwp.


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Journal ArticleDOI
TL;DR: In this paper, an analytical parametric study has been carried out to improve the understanding of the influence of hydraulic properties and rainfall conditions on rainfall infiltration mechanism and hence on the pore-water pressure distributions in single and two-layer unsaturated soil systems.
Abstract: To improve the understanding of the influence of hydraulic properties and rainfall conditions on rainfall infiltration mechanism and hence on the pore-water pressure distributions in single and two-layer unsaturated soil systems, an analytical parametric study has been carried out. Parameters considered in this study include saturated permeability (ks), desaturation coefficient (α), water storage capacity (θs-θr), and antecedent and subsequent rainfall infiltration rate (qA and qB). Moreover, the influence of soil profile heterogeneity is also investigated. The calculated results demonstrate that the infiltration process and pore-water pressure response are primarily controlled by both qα/ks and ks/α. Generally the larger the value of qα/ks , the greater the reduction of negative pore-water pressure in shallow soil layer. The larger the ratio of ks/α, the faster is the advancement of wetting front. Among the three hydraulic parameters, the effects of α and ks on pore-water pressure response are much more ...

102 citations

Journal ArticleDOI
TL;DR: In this article, spatial and temporal trends in pore water geochemistry and sediment microbial community structure are compared at three intertidal sites of a saltmarsh on Sapelo Island, GA.
Abstract: Spatial and temporal trends in pore water geochemistry and sediment microbial community structure are compared at three intertidal sites of a saltmarsh on Sapelo Island, GA. The sites include a heavily bioturbated, unvegetated creek bank, a levee with dense growth of Spartina alterniflora, and a more sparsely vegetated ponded marsh site. The redox chemistry of the pore waters ranges from sulfide-dominated at the ponded marsh site to suboxic at the creek bank site. At the three sites, the vertical redox stratification of the pore waters is more compressed in summer than in winter. The trends in redox chemistry reflect opposing effects of sediment respiration and pore water irrigation. Intense and deep burrowing activity by fiddler crabs at the creek bank site results in the efficient oxidation of reduced byproducts of microbial metabolism and, hence, the persistence of suboxic conditions to depths of 50 cm below the sediment surface. Increased supply of labile organic substrates at the vegetated sites promotes microbial degradation processes, leading to sharper redox gradients. At the levee site, this is partly offset by the higher density and deeper penetration of roots and macrofaunal burrows. Surprisingly, the microbial community structure shows little correlation with the variable vertical redox zonation of the pore waters across the saltmarsh. At the three sites, the highest population densities of aerobic microorganisms, iron- plus manganese-reducing bacteria, and sulfate reducers coexist within the upper 10 cm of sediment. The absence of a clear vertical separation of these microorganisms is ascribed to the high supply of labile organic matter and intense mixing of the topmost sediment via bioturbation.

102 citations

Journal ArticleDOI
Takatoshi Ito1
TL;DR: In this paper, the point stress criterion is applied to predict tensile failure of rock occurring in such complicated conditions, where the fracture initiation occurs when the maximum effective stress reaches the tensile strength of a rock at a point that is not on the borehole wall but is inside the rock.

102 citations

Journal ArticleDOI
TL;DR: In this article, the transport of two conservative tracers, bromide and chloride, was studied in a stony field soil under natural soil, vegetative, and climatic conditions.
Abstract: The transport of two conservative tracers, bromide and chloride, was studied in a stony field soil under natural soil, vegetative, and climatic conditions. Small tracer pulses were applied evenly over the 94-m2 plot area in April 1982 (bromide) and October 1982 (chloride). A 15-m-long, 3-m-deep transect through the plot area was extensively sampled in May 1983, approximately 400 days after the bromide and 200 days after the chloride was applied. Tracer concentrations were obtained from 842 samples taken at 61 locations along the transect. Two-dimensional contour plots of the data showed a relatively uniform displacement in the vertical direction, as well as a significant horizontal redistribution during the study period. The data were analyzed with the classical convection-dispersion equation (CDE) and with a regional stochastic model that assumes logarithmic distributions of the pore water velocity and the dispersion coefficient across the field. Both models successfully described momentary field-averaged concentration distributions but failed to predict observed concentration data in October 1984 when another, less intensive sampling was carried out. Pore water velocities could be estimated reasonably well with as few as five vertical sampling lines, whereas dispersion coefficients and solute loads required numerous additional samplings. A field scale dispersivity of about 8 cm was obtained for the CDE model. Between 75 and 130% of the applied tracers were recovered in 1982. The effects of sampling size (0.3 versus 3 kg dry soil weight) were found to be relatively small.

102 citations

Journal ArticleDOI
TL;DR: In this article, the authors present the driving factors for the interlayer creation and mud pumping phenomena in railway sub-structure and show that the ballast behavior depends on the sub-soil state.

102 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023552
2022995
2021572
2020564
2019566
2018566