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本文从计算承载梁间距对运材汽车的各点速度的影响方面入手,论述了承载梁间距对曲线行车轨迹的影响。结果表明:承载梁间距越小,运材汽车抗侧滑能力越强,侧偏值也小。 相似文献
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Improved transport planning and pricing is dependent on correct cycle times. The objective of this study was to quantify the effect of road curvature, surface roughness, gradient and truck weight on the operating speed of a conventional 60-tonne gross vehicle weight logging truck. The study used a 320-km test track consisting of both public and forest roads. The track was driven with various gross vehicle weights. Speed data was retrieved from the truck’s CAN-bus system and road data was measured with a profilograph. The key factors for operating speed were curvature and surface roughness, both of which were correlated to each other as well as partially captured by functional road class. Regression analysis quantified the individual effects of these factors as well as gradient, undulation and interactions with truck weight. A regression model is presented which explained 80% of the variation in operating speed. The results were consistent with previous studies, and the proposed models can be used to improve transport planning, cost estimation, operative route path selection and road investments. 相似文献
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Chikara Nakahata Kazuhiro Aruga Ryo Uemura Masashi Saito Kanae Kanetsuki 《Small-Scale Forestry》2014,13(2):251-266
This study examines the optimal method to extract logging residues from small, fragmented and scattered forests separately from the mechanized operational systems used on aggregated forestry operation sites. First, small-scale logging systems operated by a private logging contractor and an individual forest owner were investigated. Regression equations for estimating felling and processing cycle times were established as a function of stem and log volumes, respectively. Equations to estimate the forwarding and transporting cycle times were established as a function of the forwarding and transporting distances using the forwarding and transporting velocities, respectively. Then, equations to estimate productivities and costs were established with the cycle times, volumes and hourly operational expenses consisting of labour and machinery expenses. Finally, costs of the small-scale systems—mini-forwarder and 4 t truck operated by a private logging contractor, and manual logging and light truck operated by an individual forest owner—were estimated and compared with the mechanized operation system operated by the Forest Owners’ Association. The mechanized operation system was found to have the highest cost and could not compete for small forestry operational sites and small stem volumes. The small-scale systems could be effective for harvesting small areas. This was especially true when conducting extracting operations without machines, as done by the individual forest owner, and transporting operations by a private logging contractor, in which the hourly income of the individual forest owner was higher than the hourly labour expenses. 相似文献
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福建林区运材汽车评价模式的探讨 总被引：2，自引：0，他引：2
根据福建林区道路状况，结合农用货车性能特点，建立运材汽车评价模式，对福建林区四种有代表性的运材汽车进行了评价、并按综合性能优劣进行排序。研究结果发现：HFC1060为最优车型，NJ1060为次优型。 相似文献
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The objective of this study was to develop a predictive model for travel speed of softwood sawlog timber transport (STT) vehicles over a range of forest and provincial roads of varying condition for the South African forestry industry. Data was accumulated from both the Eastern Cape/KwaZulu-Natal and Mpumalanga forest regions of South Africa. Vehicle location and payload data were collected remotely using a combination of GPS tracking and remotely sensed data. Road condition, including road width, was assessed for each identified road segment in-field according to a visual condition indicator (VCI) index. Two STT contractors were selected from each forest region transporting pine sawlogs directly from compartment roadside landings to either a processing plant or log storage area. Five STT vehicle types, representative of transport operations in the two forest regions, were assessed. Principal component analysis was conducted to determine the degree of communality between the respective predictor variables combining road width and VCI as one factor, and truck maximum power and the percentage of (legal) maximum payload as a second factor. Comparisons of the correlations between average speed and the respective predictor variables showed that road width and percentage of maximum (legal) payload had the highest correlations. Multiple linear regression of these two factor variables were used in the model showing both variables as significant (p < 0.05) with an adjusted r2 value of 0.52. 相似文献
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农用货车在木材生产中应用的评价 总被引：2，自引：1，他引：1
从经济改革，南方林区道路状况，结合农用货车性能特点。通过与EQ1090、CA1090等车型各方面比较，对农用货车在木材生产中应用作出了评价。 相似文献
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通过分析林道等级与林道工程造价、木材运输成本和社会效益等之间关系。指出确定林道等级时,应在满足木材生产技术要求的前提下,力求综合费用最低,并给出具体确定方法。 相似文献
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Fuel accounts for more than 35% of transport costs in Swedish forestry, and reduced fuel consumption would provide immediate economic and environmental benefits. The objective of this study was to quantify the effect of road gradient, curvature and surface roughness on fuel consumption of a conventional 60-ton logging truck. The study used a 320-km test track on both public and forest roads. The track was driven with various load weights in both dry summer and wet autumn conditions. Fuel consumption data were retrieved from the truck's CAN-bus system, and road data were measured with a profilograph. Average fuel consumption was 71.4?litres/100?km. A regression analysis showed that the most important factor was the interaction between vehicle weight and gradient, explaining the 86% increase between empty and fully loaded truck. In addition, the regression analysis quantified the individual effects of undulation, curvature and surface roughness, explaining the 107% increase in fuel consumption between the highest and lowest road class. Results from the proposed regression model (R2 of 84% for a road section length of 1000?m) were consistent with predictions given by the European ARTEMIS model, and the proposed model can be used to improve cost estimation and route selection. 相似文献
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研究运用SWOT方法系统分析南平市建阳区竹山机耕路建设自身所具有的优势和劣势及外部所面临的机遇和威胁,提出建阳区竹山机耕路建设的战略与对策。结果表明:建阳区竹林资源丰富、交通条件有所改善,竹山机耕路建设优势较为明显,同时政策支持与竹产业股的成立为机耕路建设提供了一定的发展机遇。但基础设施的相对落后与管护模式的不合理及法律法规的不完善与自然灾害的影响成为区域竹山机耕路建设的劣势和威胁。因此,须结合区域自身特点,因地制宜,扬长避短,实现建阳区竹山机耕路的全面开发建设。 相似文献
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本文应用数理统计方法,建立计算CA—141型运材车最佳更新期的数学模型。通过对数学模型的计算分析发现,新车购置费和平均成本水平的高低对最佳更新期的直接影响,当新车购置费为6万元时,最佳更新期为5.5年。 相似文献
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作者根据运材岔线和装车场的装车线具有临时性的特点,研制了可拆卸的汽车运材钢筋混凝土板式轨道。其设计是把水泥混凝土板块作为纯受弯构件,在荷载作用下,根据破坏的不同阶段,并考虑到平截面、弹性体和受拉区不参加工作等假设条件,用许用应力法和极限状态法分别进行设计和比较,确定出适用于不同车型和运材方式的板块。 相似文献
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风能已成为世界上增长最快的清洁可再生能源,风力发电世界各国争相发展.然而我省风力发电项目进展较为缓慢,主要原因在于,我省公路网密度较低,许多公路等级偏低,平面线性较差,运输风电设备的长货车通行较困难.风电路的设计有一定的特殊性,我们在进行风电路设计时不能照搬规范上的数据,特殊数值需要通过计算求得,以保证风电设备的顺利运输. 相似文献
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依据汽车最优驾驶理论研制的载货汽车档位指导系统可为驾驶者提供合理档位、换档时机及最佳车速等操作信息,其特点是设计和制造比较简单,对汽车整体结构改变不大,且成本低、可靠性高。采用汽车档位指导系统可使其发动机的运转尽可能地接近最佳工作点,而汽车则处于最优的燃油经济状态之下。本文通过对一些车辆的跟踪调查,表明汽车档位指导系统的性能是很优良的,该系统在促进驾驶技术和改善汽车的燃油经济性方面都有很大的提高。它明显地促进汽车驾驶技术水平的提高,并可获得9％～11％左右的节油功效。 相似文献
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V. Kuonen 《European Journal of Forest Research》1971,90(1):153-156
Summary In Switzerland developing of forest areas is part of regional planning Access to all parts of forest is opened up by truck
roads and secondary lines (tracks, cable cranes). To obtain optimum results transport systems should be planned considering
several aspects, viz. silviculture, access, transport, recreation social welfare, economics.
Applying soil mechanics, soil stabilization and technology of road materials for pavement design permits constructing good
roads with minimum cost of, construction and maintenance.
相似文献
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A forest road network in northeastern Italy was explored by field investigations to evaluate the cost of covering annual demand
of woodchips according to three scenarios. The first scenario (A) considered the current extent of the forest road network
(mainly tractor road) and the associated qualitative characteristics; the second scenario (B) evaluated the possibility of
increasing the availability of the technical amount of forest biomass by extending the forest road network by three tractor
roads (3.9 km); the third scenario (C) considered the impact on woodchip supply of converting 9.3 km of tractor forest road
into truck forest road. At a woodchip price of 60 € t−1, the cost–supply curve of scenario C indicated a woodchip amount of 2886 t year−1, which was 561 t year−1 greater than scenario A and 161 t year−1 greater than scenario B. 相似文献
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前苏联西伯利亚森工科研所的重点研究领域是, 开发以TT-4M为通用底盘的各种集材拖拉机和装载机, 研究山地森林采伐工艺、汽车运输道路修筑新工艺, 开发小河水运机械系统, 完善采运机具维修保养系统, 研制新型制材机械以及采伐、造材、加工剩余物的综合利用等.我国森工科研主要借鉴之点是建立科研中试基地、选择适合林区经济发展条件的科研项目, 调整科研组织结构及人才结构, 开展一些林区急需的中、小型科研课题. 相似文献
20.
Fraefel Marielle Bont Leo G. Fischer Christoph 《European Journal of Forest Research》2021,140(5):1195-1209
Efficient forest management, and wood production in particular, requires a forest road network of appropriate density and bearing capacity. The road network affects the choice of a suitable extraction method and the length of the transport route from the forest, while the road standard defines the truck type that can be used.
We evaluate the forest road network’s economic suitability for harvesting operations in the entire Swiss forest, an area of about 13,000 km2 covering a range of topographies, based on the Swiss National Forest Inventory’s (NFI) forest road dataset. This dataset is based on information from an interview survey with the local forest services and includes all forest roads in Switzerland capable of carrying trucks. Extraction options and hauling routes are analysed together; thus, the entire logging process is examined.
Model results include maps of the most suitable extraction method; extraction costs; hauling costs; and a suitability map based on a combination of the results. While the larger part of the Swiss forest is classified as “suitable” for economic harvesting operations, significant portions also fall into the “limited suitability” and “not suitable” categories. Our analysis provides an objective, country-wide, spatially explicit assessment of timber accessibility. The resulting suitability map helps identify areas where timber harvesting is economic using the current forest road network, and where it is not. The model results can be used in road network planning and management, for example, by comparing road-network re-design scenarios, and compared to the spatial distribution of available wood volume.
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