Locally Available Aggregate and Sediment Production

Author(s):  
Randy B. Foltz ◽  
Mark Truebe

Selection of suitable locally available materials to build strong and durable roads with aggregate surfaces is desired to minimize road construction and maintenance costs and to minimize the detrimental effects of sedimentation. Eighteen aggregates were selected from local sources in Idaho, Oregon, South Dakota, and Washington State. Aggregate was placed in shallow metal frames and compacted to simulate a forest road. The levels of runoff and sediment from a highintensity, long-duration simulated rainstorm were measured. The material tests selected for use in the study included ones that define the basic characteristics of the aggregate, along with a number of tests intended to predict susceptibility to erosion. Each of the tests was statistically evaluated to identify those that best predicted the perceived aggregate quality. The two best indicators of aggregate quality were the results of the sand equivalent test and the P20 portion of the Oregon air degradation test. The best indicator of either runoff or sediment production was the fraction passing the 0.6-mm sieve. Acceptable aggregates, both those of good quality and those of marginal quality, exhibited a 2-order-of-magnitude range in both runoff and sediment production.

2002 ◽  
Vol 48 (161) ◽  
pp. 192-198 ◽  
Author(s):  
Peter G. Knight ◽  
Richard I. Waller ◽  
Carrie J. Patterson ◽  
Alison P. Jones ◽  
Zoe P. Robinson

AbstractSediment production at a terrestrial section of the ice-sheet margin in West Greenland is dominated by debris released through the basal ice layer. The debris flux through the basal ice at the margin is estimated to be 12–45 m3 m−1 a−1. This is three orders of magnitude higher than that previously reported for East Antarctica, an order of magnitude higher than sites reported from in Norway, Iceland and Switzerland, but an order of magnitude lower than values previously reported from tidewater glaciers in Alaska and other high-rate environments such as surging glaciers. At our site, only negligible amounts of debris are released through englacial, supraglacial or subglacial sediment transfer. Glaciofluvial sediment production is highly localized, and long sections of the ice-sheet margin receive no sediment from glaciofluvial sources. These findings differ from those of studies at more temperate glacial settings where glaciofluvial routes are dominant and basal ice contributes only a minor percentage of the debris released at the margin. These data on debris flux through the terrestrial margin of an outlet glacier contribute to our limited knowledge of debris production from the Greenland ice sheet.


2004 ◽  
Vol 118 (2) ◽  
pp. 164
Author(s):  
George W. Douglas

In Canada, Lemmon's Holly Fern, Polystichum lemmonii, is restricted to the Baldy Mountain area on the eastern side of the Okanagan River valley in south-central British Columbia. This population represents the northern limits of the species which ranges south through northern Idaho, Washington and Oregon to northern California. In British Columbia, P. lemmonii is associated with ultramafic rocky ridges within a montane forest at an elevation of 1900 m. The population in the Baldy Mountain area is relatively small, unprotected and potentially imperilled by mining exploration, forest road construction or wildfires.


2021 ◽  
Author(s):  
Andrey Manukovskiy ◽  
I. Efremov

This article discusses the features of the development and applicationBIM technologies in the preparation of BIM projects for timber roads in the Russian Federation. The main types of software products used in the preparation of BIM-projects of forest roads have been established. The procedure for using software products is given, their main types are established and functional capabilities are analyzed. The drawbacks and limitations of software products for general-purpose project management in the context of the use of BIM technologies are identified. The necessity of developing a specialized software product for the preparation of elements of projects for the organization of construction «Planworks», in order to increase the efficiency of the use of BIM-technologies in the preparation of projects of timber haul roads. The article describes the proposed procedure for using the developed software product, and also formulates the main stages of developing a project for organizing construction in it. The main list of the initial data required for the preparation of the organization’s project in the developed software product is disclosed. The features of the automated generation of a network model of tasks for the construction of structural elements of a timber road are described, the main types of generated tasks, as well as the features of automated task linking, are given. The advantages of using the developed software product at the stages of development of a technical design and construction of a timber road have been determined.


2009 ◽  
pp. 165-176 ◽  
Author(s):  
Bogdan Stefanovic ◽  
Ivan Bjelanovic

One of the three studied variant solutions of forest road conceptual design was selected based on the linear distribution of criteria, as the method of multicriteria optimization. The selection was performed with 25 parameters classified as economic, technical, production and social criteria. The parameters of technical criteria were grouped into design, construction and building parameters. Based on calculated nominal values of parameters by the given criteria, their ranking, comparison, point rating and scoring, the selected most favorable solution was variant 1.


2021 ◽  
Author(s):  
Shinya Tsuzuki ◽  
Yusuke Miyazato ◽  
Mari Terada ◽  
Shinichiro Morioka ◽  
Norio Ohmagari ◽  
...  

AbstractBackgroundThe empirical basis for a quantitative assessment of the disease burden imposed by long-COVID is currently scant. We aimed to assess the disease burden caused by long-COVID in Japan.MethodsWe conducted a cross sectional self-report questionnaire survey. The questionnaire was mailed to 530 eligible patients, who were recovered from acute COVID-19 in April 2021. Answers were classified into two groups; participants who have no symptom and those who have any ongoing symptoms that lasted longer than four weeks at the time of the survey. We compared health-related quality of life scores estimated by the EQ-5D-3L questionnaire between these two groups after adjusting basic characteristics of the participants by propensity score matching.Results349 participants reported no symptoms and 108 reported any symptoms at the time of the survey. The participants who reported any symptoms showed a lower value on a Visual Analogue Scale (median 70 [IQR 60-80]) and on the EQ-5D-3L (median 0.81 [IQR 0.77-1.0]) than those reporting no symptoms (median 85 [IQR 75-90] and 1.0 [IQR 1.0-1.0], respectively). After adjusting for background characteristics, these trends did not change substantially (Visual Analog Scale: median 70 [IQR 60-80] vs 80 [IQR 77-90], EQ-5D-3L: median 0.81 [IQR 0.76-1.0] vs 1.0 [IQR 1.0-1.0]).ConclusionsDue to their long duration, long-COVID symptoms represent a substantial disease burden expressed in impact on health-related quality of life.Trial registrationNot applicable.


Author(s):  
Ihor RUDKO ◽  
Borys BAKAY ◽  
Abdullah AKAY ◽  
Vasyl BARYLIAK ◽  
Stanislav HORZOV

This article reviews the problem of measuring the actual radius of curvature for curved sections of existing forest roads, as forestry enterprises require reliable technical information about the current conditions of operated transport networks. It was identified that at this moment, a selection of methods are used for measuring the radii of horizontal curved sections of roads, which have certain advantages and disadvantages in specific natural production conditions. For calculating the radius of curvature for auto forest road projects it is recommended to apply the method of measured angles by chord angle deviation, which is sufficiently accurate for engineering purposes and does not require usage of special high-precision equipment and tools.


2008 ◽  
Vol 8 (10) ◽  
pp. 1944-1949 ◽  
Author(s):  
Hossein Khalilpoor ◽  
Seyed Ataollah Hosseini ◽  
Majid Lotfalian ◽  
Yahya Kooch

2018 ◽  
Vol 47 (2) ◽  
pp. 136-139 ◽  
Author(s):  
Jan Lizbetin ◽  
Ladislav Bartuska

The paper deals with the methodology of handling equipment designing in intermodal transport terminals. The overall performance of the intermodal transport terminal, and hence its effectiveness, is most affected by the capacity of handling equipments that transfer intermodal transport units between transport modes. The first part of the paper describes the various types of handling equipments conventionally used in intermodal terminals. The second part of the paper contains the basic characteristics of the methodology of designing specific handling equipment and provides a calculation methodology for determining the operational needs of intermodal transport terminals.


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