scholarly journals Use of plastic geocellular modules as a replacement gravel layer for natural turf rootzones

itsrj ◽  
2021 ◽  
Author(s):  
Thomas Young ◽  
Ruth Mann ◽  
Christian Spring
Keyword(s):  
Gravel Layer ◽  
Natural Turf

Experimental Study on Hydraulic Roughness of Submerged Grass in Ecological Riverbank

2013 ◽  
Vol 838-841 ◽  
pp. 1743-1748
Author(s):  
Dian Guang Ma ◽  
Chun Xin Zhong ◽  
Wu Ning ◽  
Qing Ye ◽  
Sheng Zhu
Keyword(s):  
Flow Velocity ◽  
Roughness Coefficient ◽  
Theoretic Analysis ◽  
Mean Flow ◽  
Normal Range ◽  
Obvious Effect ◽  
Hydraulic Roughness ◽  
Natural Turf ◽  
Scouring Process ◽  
The Mean

A model experiment about the hydraulic roughness of natural turf used in riverbank was carried out in flume. To examine the rationality of experimental design, the hydraulic roughness coefficient of plexiglass-flume was tested firstly. The result was 0.0085, which is quite normal. Then the tested hydraulic roughness caused by vegetation ranges from 0.020 to 0.090 for the chosen plants, which is also acceptable. Furthermore, the tested incipient velocities of krasnozem, and paddysoil had the range of 0.55~0.65m·s-1 and 1.0~1.1m·s-1, respectively. All these experimental results are in normal range, which means that the design of this experimental is rational. Experimental research illustrate that, the roughness coefficient of plant reduces with the increasing of flow velocity. When the mean flow velocity is over 3m·s-1, Mannings n values vary between 0.025 and 0.035. This phenomenon is accord with the theoretic analysis. During the scouring process, not only the flow velocity, but also the flow duration has an obvious effect on the coarseness of vegetative bed.

Experiences with a top layer of gravel to enhance the performance of vertical flow constructed wetlands at cold temperatures

2009 ◽  
Vol 59 (6) ◽  
pp. 1111-1116 ◽  
Author(s):  
Guenter Langergraber ◽  
Alexander Pressl ◽  
Klaus Leroch ◽  
Roland Rohrhofer ◽  
Raimund Haberl
Keyword(s):  
Organic Matter ◽  
Constructed Wetlands ◽  
Common Reed ◽  
Treated Wastewater ◽  
Second Phase ◽  
Vertical Flow ◽  
Cold Temperatures ◽  
Main Layer ◽  
Gravel Layer ◽  
Filter Bed

In a first phase of this study it was shown that the Austrian effluent standards for organic matter could not be met in winter for vertical flow (VF) beds designed for and loaded with 27 g COD.m−2.d−1 (3 m2 per person equivalent). The aim of this second phase of the study was to investigate, if the performance of a constructed wetland can be enhanced, i.e. if the effluent requirements can be met, when an additional gravel layer (15 cm, 4–8 mm) is added on top of the main layer of the VF bed. The hypothesis was that this top layer would increase the thermal insulation and consequently the temperatures in the filter bed during cold periods, thus resulting in higher removal efficiencies during winter. Two VF beds were operated in parallel; one bed with such a 15 cm top layer, one without. Otherwise the construction of both beds was identical: surface area of about 20 m2, 50 cm main layer (grain size 0.06–4 mm, d10=0.2 mm; d60=0.8 mm), planted with common reed (Phragmites australis). The beds were intermittently loaded 4 times per day with mechanically pre-treated wastewater (hydraulic loading: 47 mm.d−1; median value of the influent concentration: 505 mg COD.L−1). Despite a better performance during the first winter, the bed with additional top layer showed in general a very unstable performance. It is assumed that the main reason for this was that the oxygen transfer was reduced by the additional top layer so far that suspended organic matter could not any longer be degraded in between loadings. Therefore clogging of the filter occurred.

Effects of gravel layer as thrust restraint for pipe bends subjected to earthquake loading

2021 ◽  
pp. 1-31
Author(s):  
Yoko Ohta ◽  
Yutaka Sawada ◽  
Mitsuru Ariyoshi ◽  
Yoshiyuki Mohri ◽  
Toshinori Kawabata
Keyword(s):  
Earthquake Loading ◽  
Gravel Layer

Artificial vs Natural Turf

1979 ◽  
Vol 7 (5) ◽  
pp. 39-53 ◽  
Author(s):  
Allan J. Ryan
Keyword(s):  
Natural Turf

Practical Optimization of Industrial Gravel Size in Gravel Packed Well

2011 ◽  
Vol 201-203 ◽  
pp. 383-387
Author(s):  
Jin Gen Deng ◽  
Yu Chen ◽  
Li Hua Wang ◽  
Wen Long Zhao ◽  
Ping Li
Keyword(s):  
Design Method ◽  
Control Measures ◽  
Control Effect ◽  
Gravel Layer ◽  
Gravel Size ◽  
Sand Control ◽  
Gravel Packing ◽  
Gravel Pack ◽  
The Impact ◽  
Computing Method

In the design of gravel packing sand control, the reasonable selection of gravel size is one of the keys to implementing sand control measures successfully. Aiming at the defects of commonly used methods of gravel size design and the characteristic that the gravel used in field operation is actually a mixture of gravel with multiple grain diameters, this paper builds a model of pore structure in gravel layer through researching the gravel pack structure caused by the gravel of two grain diameters mixed under actual packing conditions, calculates and analyzes the pore sizes in gravel layer. Ultimately, based on Saucier method, this paper presents a new gravel size optimization idea for gravel packing sand control with multiple grain diameters mixed, which agrees with the actual situation of industrial gravel, and gives the idea’s computing method. Considering the ideality of the model in this paper, the author has modified the computing method to make it more fit for the actual packing situation. This gravel size design method also gives consideration to the impact of formation sand uniformity on sand control effect, so it have the characteristics of good practicability, wide applicability and more accurate than other conventional methods.

Interaction Between Turbulent Open-Channel Flow and Pressure Fluctuations in Subsurface Gravel Layer

2003 ◽  
pp. 79-82
Author(s):  
Martin Detert ◽  
Gregor Kühn ◽  
Michael Klar
Keyword(s):  
Channel Flow ◽  
Open Channel ◽  
Pressure Fluctuations ◽  
Open Channel Flow ◽  
Gravel Layer

Natural turf sports surfaces

2015 ◽  
pp. 178-198
Keyword(s):  
Natural Turf

Investigating the Near Surface Loess Gravel Layer and Correcting the Static Shift of 3-D MT Data with TEM Data

2013 ◽  
Author(s):  
Z. Zhao ◽  
D.C. Li ◽  
Z.Z. Hu ◽  
S.J. Yang ◽  
H.Y. Liu ◽  
...  
Keyword(s):  
Static Shift ◽  
Near Surface ◽  
Gravel Layer

scholarly journals Surveying for Virus-vectoring Nematodes in Container-grown Blueberry Plants in Oregon

2016 ◽  
Vol 17 (3) ◽  
pp. 175-176 ◽  
Author(s):  
D. Sharma-Poudyal ◽  
C. Fraley ◽  
N. K. Osterbauer
Keyword(s):  
Soil Surface ◽  
Soil Samples ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Plastic Sheet ◽  
Gravel Bed ◽  
Effective Barrier ◽  
Gravel Layer ◽  
Potting Media ◽  
Plant Parasitic

The goal of this study was to determine the risk of finding virus-vectoring nematodes in containerized blueberry plants placed on gravel. To detect dagger nematode, soil, and potting media samples were collected from blueberry nurseries growing plants in containers using soilless potting media, with the containers placed on a gravel bed or, for one nursery, on a plastic sheet placed on the soil surface. Potting media samples were collected from containers holding plants and soil samples were collected from beneath the gravel or plastic barrier. Nematodes were extracted from all of the samples using sucrose centrifugation. No dagger or other plant parasitic nematodes were detected in any of the samples tested. These results suggest no treatment of soilless potting media is necessary before planting blueberries into containers. Similarly, the gravel layer seems to be an effective barrier for suppressing dagger and other plant parasitic nematodes. Accepted for publication 25 July 2016. Published 8 August 2016.

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