scholarly journals Evaluation of Various Perimeter Barrier Products

2021 ◽  
Author(s):  
Rabin Bhattarai ◽  
◽  
Yufan Zhang ◽  
Jacob Wood ◽  
◽  
...  
Keyword(s):  
Large Scale ◽  
Sediment Concentration ◽  
Department Of Transportation ◽  
Vegetative Cover ◽  
Buffer Strip ◽  
Erosion Rates ◽  
Sediment Removal ◽  
Loam Soil ◽  
A Site ◽  
Large Scale Tests

Construction activities entail substantial disturbance of topsoil and vegetative cover. As a result, stormwater runoff and erosion rates are increased significantly. If the soil erosion and subsequently generated sediment are not contained within the site, they would have a negative off-site impact as well as a detrimental influence on the receiving water body. In this study, replicable large-scale tests were used to analyze the ability of products to prevent sediment from exiting the perimeter of a site via sheet flow. The goal of these tests was to compare products to examine how well they retain sediment and how much ponding occurs upstream, as well as other criteria of interest to the Illinois Department of Transportation. The products analyzed were silt fence, woven monofilament geotextile, Filtrexx Siltsoxx, ERTEC ProWattle, triangular silt dike, sediment log, coconut coir log, Siltworm, GeoRidge, straw wattles, and Terra-Tube. Joint tests and vegetated buffer strip tests were also conducted. The duration of each test was 30 minutes, and 116 pounds of clay-loam soil were mixed with water in a 300 gallon tank. The solution was continuously mixed throughout the test. The sediment-water slurry was uniformly discharged over an 8 ft by 20 ft impervious 3:1 slope. The bottom of the slope had a permeable zone (8 ft by 8 ft) constructed from the same soil used in the mixing. The product was installed near the center of this zone. Water samples were collected at 5 minute intervals upstream and downstream of the product. These samples were analyzed for total sediment concentration to determine the effectiveness of each product. The performance of each product was evaluated in terms of sediment removal, ponding, ease of installation, and sustainability.

scholarly journals The impact of soil preparation on the soil erosion rates under laboratory conditions

2015 ◽  
Vol 7 (1) ◽  
pp. 885-907 ◽  
Author(s):  
A. Khaledi Darvishan ◽  
V. Homayounfar ◽  
S. H. R. Sadeghi
Keyword(s):  
Soil Erosion ◽  
Soil Loss ◽  
Sediment Concentration ◽  
Soil Disturbance ◽  
Natural Soil ◽  
Northern Iran ◽  
Erosion Rates ◽  
Soil Preparation ◽  
Loam Soil ◽  
The Impact

Abstract. The use of laboratory methods in soil erosion studies causes soil disturbance, preparation and placement in experimental plots and has been recently considered more and more because of many advantages. However, different stages of soil removal, transfer, preparation and placement in laboratory plots cause significant changes in soil structure and subsequently, the results of runoff, sediment concentration and soil loss. Knowing the rate of changes in sediment concentration and soil loss variables with respect to the soil preparation for laboratory studies is therefore inevitable to generalize the laboratory results to field conditions. However, there has been less attention to evaluate the effects of soil preparation on sediment variables. The present study was therefore conducted to compare sediment concentration and soil loss in natural and prepared soil. To achieve the study purposes, 18 field 1 m × 1 m-plots were adopted in an 18% gradient slope with sandy-clay-loam soil in the Kojour watershed, Northern Iran. Three rainfall intensities of 40, 60 and 80 mm h−1 were simulated on both prepared and natural soil treatments with three replications. The sediment concentration and soil loss at five three-minute intervals after time-to-runoff were then measured. The results showed the significant (p ≤ 0.01) increasing effects of soil preparation on the average sediment concentration and soil loss. The increasing rates of runoff coefficient, sediment concentration and soil loss due to the study soil preparation method for laboratory soil erosion plots, were 179, 183 and 1050% (2.79, 2.83 and 11.50 times), respectively.

scholarly journals EROSION DUE TO HIGH FLOW VELOCITIES: A DESCRIPTION OF RELEVANT PROCESSES

2011 ◽  
Vol 1 (32) ◽  
pp. 24 ◽  
Author(s):  
Frederik Bisschop ◽  
Paul Visser ◽  
Cees Van Rhee ◽  
Henk Jan Verhagen
Keyword(s):  
Large Scale ◽  
Analytical Formula ◽  
Sediment Concentration ◽  
Soil Mass ◽  
High Flow ◽  
Granular Soils ◽  
Erosion Process ◽  
Erosion Rates ◽  
Clear Insight ◽  
Flow Velocities

Convential models for the erosion of non-cohesive sediments overestimate the erosion rate induced by high flow velocities. These high flow velocities occur, for instance, in breaching of embankments or dunes (flow velocities up to 10 m/s) or in jetting sand with a trailing suction hopper dredger (30 to 60 m/s). At these very large flow velocities the erosion process is significantly influenced by the properties of the soil mass (non-cohesive particles). Governing parameters at higher flow velocities are dilatancy, permeability and the (un)drained shear strength of the soil. The sediment concentration in the water also influences the erosion process, especially in case of higher erosion rates. Based on the concept of Van Rhee (2007, 2010) a simple analytical formula is derived that gives a clear insight into the parameters influencing hindered erosion. The concept of hindered erosion is explained by two properties of granular soils: dilatancy and permeability. This implicates that the erosion behaviour of granular soils cannot be described by the behaviour of single particles alone. The properties of the whole soil mass should be considered in predicting erosion at higher flow velocities. Results of a large-scale breach experiment performed in 1994 in the Zwin Channel in the Netherlands (Visser, 1998) are analyzed to evaluate the formula.

Impact of vegetative cover and slope on runoff, erosion, and water quality for field plots on a range of soil and spoil materials on central Queensland coal mines

Soil Research ◽  
2000 ◽  
Vol 38 (2) ◽  
pp. 313 ◽  
Author(s):  
C. Carroll ◽  
L. Merton ◽  
P. Burger
Keyword(s):  
Water Quality ◽  
Soil Erosion ◽  
Overland Flow ◽  
Salt Content ◽  
Vegetative Cover ◽  
Rhodes Grass ◽  
Erosion Rates ◽  
Mine Sites ◽  
The Impact ◽  
Field Plots

In 1993, a field study commenced to determine the impact of vegetative cover and slope on runoff, erosion, and water quality at 3 open-cut coal mine sites. Runoff, sediment, and water quality were measured on 0.01-ha field plots from 3 slope gradients (10, 20, 30%), with pasture and tree treatments imposed on soil and spoil material, and 2 soil and spoil plots left bare. The greatest soil erosion occurred before pasture cover established, when a large surface area of soil (>0.5 plot area) was exposed to rainfall and overland flow. Once buffel grass (Cenchrus ciliaris) colonised soil plots, there were negligible differences in soil erosion between slope gradients. On spoil, Rhodes grass (Chloris gayana) reduced in situ soluble salt content, and reduced runoff electrical conductivity to levels measured in surrounding creeks. Where spoil crusted there was poor vegetative growth and unacceptably large runoff and erosion rates throughout the study.

SYNTHETIC PHEROMONES DISRUPT MALE DIORYCTRIA SPP. MOTHS IN A LOBLOLLY PINE SEED ORCHARD

2000 ◽  
Vol 132 (3) ◽  
pp. 345-351 ◽  
Author(s):  
Gary L. DeBarr ◽  
James L. Hanula ◽  
Christine G. Niwa ◽  
John C. Nord
Keyword(s):  
Loblolly Pine ◽  
Large Scale ◽  
Sex Pheromones ◽  
Mating Disruption ◽  
Seed Orchard ◽  
Control Treatment ◽  
Tetradecenyl Acetate ◽  
Lepidoptera Pyralidae ◽  
Trap Catches ◽  
Large Scale Tests

AbstractSynthetic sex pheromones released in a loblolly pine, Pinus taeda L. (Pinaceae), seed orchard interfered with the ability of male coneworm moths, Dioryctria Zeller spp. (Lepidoptera: Pyralidae), to locate traps baited with sex pheromones or live females. Pherocon 1C® traps baited with synthetic pheromones or live conspecific females were hung near the center of two 1.2-ha circular plots during emergence of Dioryctria amatella (Hulst), Dioryctria disclusa (Heinrich), and Dioryctria merkeli (Mutuura and Munroe). In a paired design, trap catches for the mating-disruption treatment with synthetic pheromone dispensers consisting of three polyvinyl chloride rods placed in every tree were compared with the control treatment. Treatments were alternated at intervals of 2–3 d. Trap catches of D. amatella were reduced by 91% when plots were treated with 2.5 g/ha of Z-11-hexadencenyl acetate. Catches were reduced by 99.5% for D. disclusa and by 97% for D. merkeli when plots were treated with 12.5 g/ha of Z-9-tetradecenyl acetate, whereas catches of D. amatella were unaffected by this mating-disruption treatment. Daily disappearance of Z-9-tetradecenyl acetate from the dispensers averaged 0.46 g/ha or less. Manually placing dispensers on nylon lines in the tops of trees was an effective method for releasing synthetic Dioryctria pheromones in the orchard. These data suggest it may be feasible to prevent mating of Dioryctria spp. in pine seed orchards by using synthetic pheromones for mating disruption, but large-scale tests will be required to demonstrate cone protection.

scholarly journals Seismic Behavior and Force-Displacement Characterization of Neotype Column-Slab High Piers

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
YanQun Zhou ◽  
YeZhi Zhang ◽  
MeiXin Ye ◽  
MengSi Zhan
Keyword(s):  
Seismic Behavior ◽  
Large Scale ◽  
Scale Model ◽  
Test Results ◽  
Lateral Displacements ◽  
High Pier ◽  
Experimental Values ◽  
Large Scale Tests ◽  
Force Displacement

The seismic behavior and plasticity spreading of a neotype column-slab high pier are researched in this paper. Four scale model tests of a web slab with two boundary columns are carried out under cyclic inelastic lateral displacements simulating seismic response. The test results show that the neotype column-slab high pier has strong and stable bearing capacity, good ductility, and energy dissipation capacity. The experimental values pertaining to the spread of plasticity are derived. An approach for deriving the spread of plasticity analytically is deduced and applied to the four tests. This method accurately assesses a pier’s spread of plasticity for most ductility levels. At nearly all ductility levels, the mean difference between analytical assessments of the spread of plasticity and results from 4 large-scale tests is 12% with a 9% coefficient of variation.

scholarly journals Development and Assessment of a New Framework for Agricultural Nonpoint Source Pollution Control

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3156
Author(s):  
Lili Zhou ◽  
Runzhe Geng
Keyword(s):  
Spatial Distribution ◽  
Large Scale ◽  
Factor Model ◽  
Five Factor Model ◽  
Pollution Source ◽  
Nonpoint Source ◽  
Vegetation Coverage ◽  
Buffer Strip ◽  
Rural Living ◽  
Agricultural Nonpoint Source

The transport of agricultural nonpoint source (NPS) pollutants in water pathways is affected by various factors such as precipitation, terrain, soil erosion, surface and subsurface flows, soil texture, land management, and vegetation coverage. In this study, based on the transmission mechanism of NPS pollutants, we constructed a five-factor model for predicting the path-through rate of NPS pollutants. The five indices of the hydrological processes, namely the precipitation index (α), terrain index (β), runoff index (TI), subsurface runoff index (LI), and buffer strip retention index (RI), are integrated with the pollution source data, including the rural living, livestock and farmland data, obtained from the national pollution source census. The proposed model was applied to the headwater of the Miyun Reservoir watershed for identifying the areas with high path-through rates of agricultural NPS pollutants. The results demonstrated the following. (1) The simulation accuracy of the model is acceptable in mesoscale watersheds. The total nitrogen (TN) and total phosphorus (TP) agriculture loads were determined as 705.11 t and 3.16 t in 2014, with the relative errors of the simulations being 19.62% and 24.45%, respectively. (2) From the spatial distribution of the agricultural NPS, the TN and TP resource loads were mainly distributed among the upstream of Dage and downstream of Taishitun, as well as the towns of Bakshiying and Gaoling. The major source of TN was found to be farmland, accounting for 47.6%, followed by livestock, accounting for 37.4%. However, the path-through rates of TP were different from those of TN; rural living was the main TP source (65%). (3) The path-through rates of agricultural NPS were the highest for the towns of Wudaoying, Dage, Tuchengzi, Anchungoumen, and Huodoushan, where the path-through rate of TN ranged from 0.17 to 0.26. As for TP, it was highest in Wudaoying, Kulongshan, Dage, and Tuchengzi, with values ranging from 0.012 to 0.019. (4) A comprehensive analysis of the distribution of the NPS pollution load and the path-through rate revealed the towns of Dage, Wudaoying, and Tuchengzi as the critical source areas of agricultural NPS pollutants. Therefore, these towns should be seriously considered for effective watershed management. In addition, compared with field monitoring, the export coefficient model, and the physical-based model, the proposed five-factor model, which is based on the path-through rate and the mechanism of agricultural NPS pollutant transfer, cannot only obtain the spatial distribution characteristics of the path-through rate on a field scale but also be applicable to large-scale watersheds for estimating the path-through rates of NPS pollutants.

scholarly journals LARGE AND SMALL SCALE WAVE OVERTOPPING MEASUREMENTS FOR AFSLUITDIJK REHABILITATION PROJECT

2020 ◽  
pp. 15
Author(s):  
Wouter Ockeloen ◽  
Coen Kuiper ◽  
Sjoerd van den Steen
Keyword(s):  
Water Management ◽  
Physical Model ◽  
Large Scale ◽  
Wadden Sea ◽  
Model Tests ◽  
Small Scale ◽  
Water Safety ◽  
Wave Overtopping ◽  
Physical Model Tests ◽  
Large Scale Tests

The 'Afsluitdijk' is a 32 km enclosure dam which separates the Wadden sea and the Lake IJssel. The dam currently undergoes a major rehabilitation to meet the requirements with regard to water safety. The Dutch Ministry of infrastructure and Water Management (Rijkswaterstaat division) has commissioned Levvel, a consortium of BAM, Van Oord and Rebel, to prepare the design and carry out the reconstruction of the dam including sluices and highway. The project includes reinforcement of the armour layers and wave overtopping reduction. As part of the contract Rijkswaterstaat prescribed the contractor (Levvel) to verify the design with large scale physical model tests (min. 1:3 scale). These tests were carried out in the Delta Flume of Deltares. Prior to the large scale tests, smaller scale tests (1:20) have been carried out to optimize the design with regard to armour stability and wave overtopping. The research described here focuses on the wave overtopping.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/kPga0wVCCIE

scholarly journals LOADS ON WIND TURBINES ACCESS PLATFORMS WITH GRATINGS

2011 ◽  
Vol 1 (32) ◽  
pp. 65
Author(s):  
Thomas Lykke Andersen ◽  
Peter Frigaard ◽  
Michael R Rasmussen ◽  
Luca Martinelli
Keyword(s):  
Drag Coefficient ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Large Scale ◽  
Peak Load ◽  
Multiplication Factor ◽  
Preliminary Results ◽  
Different Types ◽  
The Many ◽  
Large Scale Tests

The present paper deals with loads on wind turbine access platforms. The many planned new wind turbine parks together with the observed damages on platforms in several existing parks make the topic very important. The paper gives an overview of recently developed design formulae for different types of entrance platforms. Moreover, the paper present new results on loads on grates based on both drag coefficient measurements and preliminary results on slamming from large scale tests. As expected both investigations show that platforms with grates give a significant reduction in the loads compared to closed plate platforms. The grate multiplication factor, defined as the peak load on the grate platform relative to the peak load on a closed plate platform was found approximately equal to the solidity of the grate.

The Belgian Demonstration Programme for the Disposal of High-Level and Long-Lived Radioactive Waste

2006 ◽  
Vol 932 ◽  
Author(s):  
Bernier Frédéric ◽  
Demarche Marc ◽  
Bel Johan
Keyword(s):  
Radioactive Waste ◽  
Thermal Load ◽  
Large Scale ◽  
Mechanical Response ◽  
Boom Clay ◽  
Geological Formation ◽  
Important Input ◽  
Clay Layers ◽  
High Level ◽  
Large Scale Tests

ABSTRACTThe EIG EURIDICE is responsible for performing large-scale tests, technical demonstrations and experiments so as to assess the feasibility of a final disposal of vitrified radioactive waste in deep clay layers. This programme is part of the Belgian Research and Development programme managed by ONDRAF/NIRAS. The research infrastructure includes the Underground Research Facilities HADES (URF HADES) in the Boom Clay geological formation and surface facilities. The achievements of the demonstration programme are the demonstration of the construction of shafts and galleries at industrial scale, the characterisation of the hydro-mechanical response of the host rock, and the “OPHELIE mock-up” a large scale hydration test under thermal load of pre-fabricated bentonite blocks. The future works will consist mainly in the realisation of the “PRACLAY experiments” including a large scale heater test. The large scale heater test has to demonstrate that Boom Clay is suitable, in terms of performance of the disposal system, to undergo the thermal load induced by the vitrified waste. The combined effect of the excavation and the thermal load will be investigated. A long term (more than 10 years) large scale heater test would be representative of the most penalizing conditions that could be encountered in the real disposal. The results of this test will constitute an important input for the Safety and Feasibility Cases 1 (SFC-1, 2013) and 2 (SFC-2, 2020).

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