The Experts below are selected from a list of 129 Experts worldwide ranked by ideXlab platform
Guy R Mcpherson - One of the best experts on this subject based on the ideXlab platform.
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impacts of fire suppression activities on natural communities
Conservation Biology, 2004Co-Authors: Dana M Backer, Sara E Jensen, Guy R McphersonAbstract:The ecological impacts of wildland fire-suppression activities can be significant and may surpass the impacts of the fire itself. A recent paradigm shift from fire control to fire management has resulted in increased attention to minimizing the negative effects of suppression. While the philosophy behind minimum- impact suppression tactics has provided a good first step in this direction, increased attention to the ecological effects of suppression is needed, especially in the management of public lands. We reviewed the potential impacts of suppression on land, air, and water resources and the impacts of using fire to help control fire. Effects on land resources include erosion, which is exacerbated by the construction of fire lines, Temporary Roads, and helicopter pads, and some postfire rehabilitation activities. Although the fire itself is the most obvious source of air pollution, the vehicles used in suppression activities contribute to this problem and to noise pollution. Water resources, including aquatic flora and fauna, may be seriously affected by suppression activities that can increase erosion, sedimentation, turbidity, and chemical contamination. Finally, the use of backburns and burnout operations contributes to the risk of soil and water contamination, increases the total area burned, and promotes more intense fires or more homogeneous burned areas. Although no fire-management strategy should be applied uniformly, some general techniques such as use of natural clearings, natural barriers, and appropriately sized fire lines, "leave no-trace" camping, and careful application of fuels and retardants can be employed to minimize the impacts of suppression.
Kuttah, Dina K - One of the best experts on this subject based on the ideXlab platform.
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En översikt om portabla vägar och flygfält : användning av mattor som tillfälliga ochsemipermanenta vägar och flygfält
'Linkoping University Electronic Press', 2019Co-Authors: Kuttah, Dina KAbstract:Matting systems used as roadways and airfields are new innovative techniques used to solve mobility problems and make it easier to get around and transport goods under different climate and traffic conditions. The portable Roads are extremely versatile and can be used for servicing areas with poor ground conditions, heavy load requirements and high traffic density. They could be used to facilitate vehicular access into areas that contain saturated soils, wetlands or soft/poor subgrade conditions and make secluded areas accessible (remote regions in general.). Moreover, portable Roads can be used as Temporary Roads for emergency situations to enable aid deliveries to disaster areas, or during maintenance of existing Roads or as Temporary Roads during a traffic jam. Regarding the portable airfields, some portable runways have been developed to support the heavy rolling loads, including heavy unmanned aircrafts and heavy maintenance equipment. Most of the available portable airfields are used in remote areas where existing runway or airport infrastructure is limited or non-existent. The use of mats to construct an airfield depends on many factors, such as ground conditions, the type and weight of aircraft being deployed, the expected usage levels, and the time available to construct the airfield. The objective of this report is to provide a practical perspective on construction and performance characteristics of some available portable Roads and airfields systems that can be used to solve Temporary and semi-permanent transport problems. Literature results are presented to educate the readers on available systems’ types and the best uses of each system in different applications.Portabla vägar och flygfält är nya och innovativa tekniker för att hålla transportvägar öppna under svåra klimat- och trafikförhållanden. De portabla vägarna är extremt mångsidiga och kan användas till serviceområden med dåliga grundförhållanden, höga lastkrav och stor trafikintensitet. De underlättar fordonstrafik till områden med vattenmättade jordar, våtmarker eller andra områden med mjuka/dåliga undergrundsförhållanden och gör avskilda områden tillgängliga (ofta i avlägsna trakter). Dessutom kan portabla vägar användas som tillfälliga vägar i akutsituationer för att möjliggöra nödleveranser till utsatta samhällen, vid underhåll av befintliga vägar eller som tillfälliga vägar vid trafikstockning inne i städer. Beträffande flygfält har en del portabla start- och landningsbanor utvecklats för att klara tunga rullande laster inklusive obemannade flygplan och tunga underhållsutrustningar. De flesta av de portabla flygfälten används i avlägsna områden där ”flyginfrastrukturen” är begränsad eller saknas helt. Hur underlaget (mattorna) till flygfältskonstruktioner görs, beror på många faktorer, t.ex. grundförhållanden, flygplanstyper och dess laster, förväntad användning samt tillgänglig konstruktionstid av flygfälten. Målet med den här rapporten är att ge en inblick på konstruktion och prestanda hos de portabla väg- och flygfältssystem som finns för att lösa tillfälliga och semipermanenta transportproblem. Resultatet av litteraturstudien visar på de tillgängliga typer av system som finns och hur de bäst ska användas (i olika applikationer)
Ian Jefferson - One of the best experts on this subject based on the ideXlab platform.
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Controlled heavy haul traffic loading as a method to remediate liquefiable soft silts
Canadian Geotechnical Journal, 2019Co-Authors: Christopher J. Krechowiecki-shaw, A.c.d. Royal, Ian JeffersonAbstract:Transportation of extremely large indivisible loads (10,000 to 30,000 tonnes) is becoming increasingly popular to allow offsite modular construction of infrastructure for oil and gas, mining and renewable energy projects in remote areas. Such exceptionally large transient loads could encounter unusual geohazards; there is a risk of metastable liquefaction when crossing soft alluvium, causing sudden failure, potential casualties and severe production delays. Furthermore, Temporary Roads for these payloads are a large cost to such projects; conventionally designed earthworks and/or ground improvement is often unaffordable or logistically impossible. This laboratory study indicates the fabric can be strengthened, and the hazard reduced, if the soil is subject to careful repeated loading which rearranges the initially precarious fabric through gradual accumulation of plastic strains. A novel remediation technique for these Temporary haul Roads is proposed; managed deployment of increasingly heavy haul vehicle...
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Routes for exceptional loads:: a new soil mechanics perspective
Proceedings of the Institution of Civil Engineers - Transport, 2017Co-Authors: Christopher J. Krechowiecki-shaw, A.c.d. Royal, Ian Jefferson, Gurmel S. GhataoraAbstract:Off-site prefabrication can bring cost, quality and programme benefits to construction projects but often requires the transportation of large, indivisible loads (in the order of 1000–10 000 t) on Temporary routes that can cross soft soils. Through simple numerical modelling, this paper demonstrates that the fundamental behaviour of the ground supporting these large loads can differ significantly from that expected in conventional road design practice; the interaction between many closely spaced wheels means the vehicle's influence depth and failure mechanism are significantly deeper. Surface soils are less influential. Deeper soil was found to be more prone to local yield, developing large localised strains at low proportions (10–30%) of the ultimate capacity. Instead of designing Temporary Roads to avoid yield and degradation under cyclic loads, significant savings may be possible if limited degradation is permitted, with recovery through consolidation between loads. Investigation and monitoring of deep...
Christopher J. Krechowiecki-shaw - One of the best experts on this subject based on the ideXlab platform.
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Controlled heavy haul traffic loading as a method to remediate liquefiable soft silts
Canadian Geotechnical Journal, 2019Co-Authors: Christopher J. Krechowiecki-shaw, A.c.d. Royal, Ian JeffersonAbstract:Transportation of extremely large indivisible loads (10,000 to 30,000 tonnes) is becoming increasingly popular to allow offsite modular construction of infrastructure for oil and gas, mining and renewable energy projects in remote areas. Such exceptionally large transient loads could encounter unusual geohazards; there is a risk of metastable liquefaction when crossing soft alluvium, causing sudden failure, potential casualties and severe production delays. Furthermore, Temporary Roads for these payloads are a large cost to such projects; conventionally designed earthworks and/or ground improvement is often unaffordable or logistically impossible. This laboratory study indicates the fabric can be strengthened, and the hazard reduced, if the soil is subject to careful repeated loading which rearranges the initially precarious fabric through gradual accumulation of plastic strains. A novel remediation technique for these Temporary haul Roads is proposed; managed deployment of increasingly heavy haul vehicle...
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Routes for exceptional loads:: a new soil mechanics perspective
Proceedings of the Institution of Civil Engineers - Transport, 2017Co-Authors: Christopher J. Krechowiecki-shaw, A.c.d. Royal, Ian Jefferson, Gurmel S. GhataoraAbstract:Off-site prefabrication can bring cost, quality and programme benefits to construction projects but often requires the transportation of large, indivisible loads (in the order of 1000–10 000 t) on Temporary routes that can cross soft soils. Through simple numerical modelling, this paper demonstrates that the fundamental behaviour of the ground supporting these large loads can differ significantly from that expected in conventional road design practice; the interaction between many closely spaced wheels means the vehicle's influence depth and failure mechanism are significantly deeper. Surface soils are less influential. Deeper soil was found to be more prone to local yield, developing large localised strains at low proportions (10–30%) of the ultimate capacity. Instead of designing Temporary Roads to avoid yield and degradation under cyclic loads, significant savings may be possible if limited degradation is permitted, with recovery through consolidation between loads. Investigation and monitoring of deep...
Dana M Backer - One of the best experts on this subject based on the ideXlab platform.
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impacts of fire suppression activities on natural communities
Conservation Biology, 2004Co-Authors: Dana M Backer, Sara E Jensen, Guy R McphersonAbstract:The ecological impacts of wildland fire-suppression activities can be significant and may surpass the impacts of the fire itself. A recent paradigm shift from fire control to fire management has resulted in increased attention to minimizing the negative effects of suppression. While the philosophy behind minimum- impact suppression tactics has provided a good first step in this direction, increased attention to the ecological effects of suppression is needed, especially in the management of public lands. We reviewed the potential impacts of suppression on land, air, and water resources and the impacts of using fire to help control fire. Effects on land resources include erosion, which is exacerbated by the construction of fire lines, Temporary Roads, and helicopter pads, and some postfire rehabilitation activities. Although the fire itself is the most obvious source of air pollution, the vehicles used in suppression activities contribute to this problem and to noise pollution. Water resources, including aquatic flora and fauna, may be seriously affected by suppression activities that can increase erosion, sedimentation, turbidity, and chemical contamination. Finally, the use of backburns and burnout operations contributes to the risk of soil and water contamination, increases the total area burned, and promotes more intense fires or more homogeneous burned areas. Although no fire-management strategy should be applied uniformly, some general techniques such as use of natural clearings, natural barriers, and appropriately sized fire lines, "leave no-trace" camping, and careful application of fuels and retardants can be employed to minimize the impacts of suppression.
