Modeling subsoil drainage systems for urban roadways

1999 ◽  
Vol 26 (6) ◽  
pp. 799-809 ◽  
Author(s):  
Robert Y Cyr ◽  
Paul Chiasson
Keyword(s):  
Hydraulic Conductivity ◽  
Cross Section ◽  
Water Infiltration ◽  
Conductivity Measurements ◽  
Drainage Systems ◽  
Section Design ◽  
Drainage Pipe ◽  
Seepage Modeling ◽  
Roadway Design ◽  
The City

Water infiltration and seepage in a roadway infrastructure is modeled from a cross section design of a residential street used by the City of Moncton (Department of Engineering). Field hydraulic conductivity measurements necessary for the modeling are also presented. Benefits of having a subsoil drainage systems (perforated drainage pipe and drainage mat) are well demonstrated. Some drainage problems caused by insufficient hydraulic conductivity, segregation, and limits on gradation curves for the gravel base foundation, as specified by the City of Moncton, are also discussed.Key words: roadway design, subsoil drainage, seepage modeling, field permeability measurements.

Spatial Variability of Contaminant Transport in a Fractured Till, Avedøre Denmark

1999 ◽  
Vol 30 (4-5) ◽  
pp. 333-360 ◽  
Author(s):  
Larry McKay ◽  
Johnny Fredericia ◽  
Melissa Lenczewski ◽  
Jørn Morthorst ◽  
Knud Erik S. Klint
Keyword(s):  
Hydraulic Conductivity ◽  
Spatial Variability ◽  
Field Experiment ◽  
Contaminant Transport ◽  
Tracer Test ◽  
Conductivity Measurements ◽  
Fine Grained ◽  
Downward Migration ◽  
Rapid Transport ◽  
High Degree

A field experiment shows that rapid downward migration of solutes and microorganisms can occur in a fractured till. A solute tracer, chloride, and a bacteriophage tracer, PRD-1, were added to groundwater and allowed to infiltrate downwards over a 4 × 4 m area. Chloride was detected in horizontal filters at 2.0 m depth within 3-40 days of the start of the tracer test, and PRD-1 was detected in the same filters within 0.27 - 27 days. At 2.8 m depth chloride appeared in all the filters, but PRD-1 appeared in only about one-third of the filters. At 4.0 m depth chloride appeared in about one-third of the filters and trace amounts of PRD-1 were detected in only 2 of the 36 filters. Transport rates and peak tracer concentrations decreased with depth, but at each depth there was a high degree of variability. The transport data is generally consistent with expectations based on hydraulic conductivity measurements and on the observed density of fractures and biopores, both of which decrease with depth. Transport of chloride was apparently retarded by diffusion into the fine-grained matrix between fractures, but the rapid transport of PRD-1, with little dispersion, indicates that it was transported mainly through the fractures.

scholarly journals The Urban Environment Impact of Climate Change Study and Proposal of the City Micro-Environment Improvement

2021 ◽  
Vol 13 (8) ◽  
pp. 4096
Author(s):  
Jozefína Pokrývková ◽  
Ľuboš Jurík ◽  
Lenka Lackóová ◽  
Klaudia Halászová ◽  
Richard Hanzlík ◽  
...  
Keyword(s):  
Management Practices ◽  
Water Infiltration ◽  
Environment Impact ◽  
Management Procedures ◽  
Aging Infrastructure ◽  
Continue Research ◽  
Rainwater Management ◽  
The Given ◽  
The City ◽  
Very High

The water management of cities and villages faces many challenges. Aging infrastructure systems operate for many years after their theoretical lifetime (operation) with a very high need for reconstruction and repair. The solution is proper rainwater management. The investigated area is part of the cadastral area of the Nitra city. This article is based on the use of geographic information systems (GIS) as tools in proposing water retention measures that are needed to improve the microenvironment of the city. We proceeded in several steps, which consisted of area analysis, survey, surface runoff calculations in urbanized areas, proposal of a suitable solution for given location. For real possibilities of rainwater management procedures, a new site on the outskirts of the city was selected. In the given locality, it was possible to use water infiltration as a solution. The locality has suitable conditions of land ownership, pedological conditions, the slope of the area and also the interest of the inhabitants in the ecological solution. The outlined study indicates the need to continue research on the reliability of rainwater management practices.

Assessment of clogging in constructed wetlands by saturated hydraulic conductivity measurements

2019 ◽  
Vol 79 (2) ◽  
pp. 314-322 ◽  
Author(s):  
F. Licciardello ◽  
R. Aiello ◽  
V. Alagna ◽  
M. Iovino ◽  
D. Ventura ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Hydraulic Conductivity ◽  
Constructed Wetlands ◽  
Spatial Scales ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Test Method ◽  
Conductivity Measurements ◽  
Multiple Spatial Scales ◽  
Ks Values

Abstract This study aims at defining a methodology to evaluate Ks reductions of gravel material constituting constructed wetland (CW) bed matrices. Several schemes and equations for the Lefranc's test were compared by using different gravel sizes and at multiple spatial scales. The falling-head test method was implemented by using two steel permeameters: one impervious (IMP) and one pervious (P) on one side. At laboratory scale, mean K values for a small size gravel (8–15 × 10−2 m) measured by the IMP and the P permeameters were equal to 19,466 m/d and 30,662 m/d, respectively. Mean Ks values for a big size gravel (10–25 × 10−2 m) measured by the IMP and the P permeameters were equal to 12,135 m/d and 20,866 m/d, respectively. Comparison of Ks values obtained by the two permeameters at laboratory scale as well as a sensitivity analysis and a calibration, lead to the modification of the standpipe equation, to evaluate also the temporal variation of the horizontal Ks. In particular, both permeameters allow the evaluation of the Ks decreasing after 4 years-operation and 1–1.5 years' operation of the plants at full scale (filled with the small size gravel) and at pilot scale (filled with the big size gravel), respectively.

scholarly journals Laboratory and In Situ Determination of Hydraulic Conductivity and Their Validity in Transient Seepage Analysis

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1131
Author(s):  
Soonkie Nam ◽  
Marte Gutierrez ◽  
Panayiotis Diplas ◽  
John Petrie
Keyword(s):  
Hydraulic Conductivity ◽  
Field Measurements ◽  
Natural Soil ◽  
In Situ Tests ◽  
Seepage Analysis ◽  
Soil Deposits ◽  
Seepage Modeling ◽  
Sample Disturbance

This paper critically compares the use of laboratory tests against in situ tests combined with numerical seepage modeling to determine the hydraulic conductivity of natural soil deposits. Laboratory determination of hydraulic conductivity used the constant head permeability and oedometer tests on undisturbed Shelby tube and block soil samples. The auger hole method and Guelph permeameter tests were performed in the field. Groundwater table elevations in natural soil deposits with different hydraulic conductivity values were predicted using finite element seepage modeling and compared with field measurements to assess the various test results. Hydraulic conductivity values obtained by the auger hole method provide predictions that best match the groundwater table’s observed location at the field site. This observation indicates that hydraulic conductivity determined by the in situ test represents the actual conditions in the field better than that determined in a laboratory setting. The differences between the laboratory and in situ hydraulic conductivity values can be attributed to factors such as sample disturbance, soil anisotropy, fissures and cracks, and soil structure in addition to the conceptual and procedural differences in testing methods and effects of sample size.

Cross-Section Design of the Crash Box to Maximize Energy Absorption

2011 ◽  
Author(s):  
Hwan Hak Jang ◽  
Hyun-Ah Lee ◽  
Sang-Il Yi ◽  
Dae Seung Kim ◽  
Heui Won Yang ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Cross Section ◽  
Section Design

scholarly journals Difficulties and modifications in the use of available methods for hydraulic conductivity measurements in highly clogged horizontal subsurface flow constructed wetlands

2017 ◽  
Vol 76 (7) ◽  
pp. 1666-1675 ◽  
Author(s):  
Mateus Pimentel Matos ◽  
André Baxter Barreto ◽  
Gabriel Rodrigues Vasconcellos ◽  
Antonio Teixeira Matos ◽  
Gustavo Ferreira Simões ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Constructed Wetlands ◽  
Subsurface Flow ◽  
The Other ◽  
Good Representation ◽  
Horizontal Distance ◽  
Conductivity Measurements ◽  
Construction Time ◽  
Horizontal Subsurface Flow ◽  
Subsurface Flow Constructed Wetlands

Despite the fact that several authors consider the available measurement methods of hydraulic conductivity (ks) suitable for a good representation of the bed condition and clogging potential in horizontal subsurface flow constructed wetlands, others have questioned their adequacy. In this work, hydraulic conductivity measurements with conventional and modified methods were undertaken in two small full-scale units, one planted with cattail (Typha latifolia) and the other unplanted. Both units had already been operating for seven years and showed a high degree of clogging. It was observed that the use of the falling head method, with the introduction of the tubes during the test, provided results without a clear spatial trend. On the other hand, tests done on monitoring wells inserted during construction time showed, as expected, ks increasing with the horizontal distance from the inlet, but without reflecting actual field conditions. It was observed that, as the bed became more clogged, the use of the reported methods became more complex, suggesting the need of other methodologies. The use of planted fixed reactors (removable baskets installed in the bed) with evaluation of ks at constant head in the laboratory showed potential for the characterization of the hydrodynamic properties of the porous medium.

HYDRAULIC CONDUCTIVITY MEASUREMENTS UTILIZING HEAT-SHRINKABLE TUBING

Ground Water ◽  
1978 ◽  
Vol 16 (1) ◽  
pp. 49-50
Author(s):  
David R. Buss ◽  
Bryson D. Trexler ◽  
William A. Kneller
Keyword(s):  
Hydraulic Conductivity ◽  
Conductivity Measurements

Evaluating the Efficiency of Crushed Gravel Filters around Field Drains

2021 ◽  
Author(s):  
Amer Al-Haddad ◽  
◽  
Dhuha Mahdi ◽  
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Surface ◽  
Filter Material ◽  
Head Loss ◽  
Surface Flow ◽  
Laboratory Work ◽  
Drain Pipe ◽  
Drainage Systems ◽  
Total Head ◽  
Irrigation Condition

Engineers have employed various ways to protect drain openings from the entry of sediment with varying degrees of success. This study aims to compare and evaluate the hydraulic performance and efficiency of using natural graded gravel filter and crushed gravel filter in drainage systems. An aquifer tank (sand tank) 70 cm long, 50 cm wide and 80 cm high, a perforated drain pipe of 50 mm diameter was used in the laboratory work. The laboratory study was performed with two types of soil: loam and loamy sand. These two soils were used with the two types of gravel filters after taking the particle size distribution test for the two soils. For each case, the inflow was applied to the model from the soil surface (to represent irrigation condition) and from the sides of the tank (to represent sub –surface flow condition and effluence of the groundwater). Each case involved ten runs; for each run, discharge, total head loss, and amount of sediment were recorded. It was found that crushed gravel filter would work similarly to natural graded gravel filter after a certain time from the beginning of runs. It was also found that the discharge and sediment when using crushed gravel filter were close to or equal to that with natural graded gravel filter. The hydraulic conductivity and the exit gradient values were calculated in this research. It was found that their values were so different between the two types of filters, but at the end of the laboratory work, the hydraulic conductivity would be approximately the same. The exit gradient of crushed gravel filter was lower than that of natural graded gravel filter due to the large pores between the filter particles. Finally, the results showed that, it is possible to use crushed gravel filter material in drainage systems, which is less costly and easier to place than natural graded gravel filter.

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