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公路特大型泥石流研究及防治新理念 总被引:13,自引:1,他引:13
作为我国一种严重的公路水毁类型,公路特大型泥石流灾害至今尚未解决,本文建构了该类泥石流研究及防治新理念,对于公路建筑物的安全与稳定、确保公路交通有序进行具有重要意义。研究认为,公路泥石流研究及防治的主要对象是具有大冲大淤性能、毁损作用强烈的特大型泥石流;必须遵循以泥石流发育机理研究为基础、防治技术研究为手段、防治工程研究为目的的研究原则;详细分析了公路泥石流水毁模式,概化分析了冲淤变动型沟谷泥石流的发育特性;开发了防治效果极佳的速流结构,运用运动状态函数法建构了速流结构设计理念,运用动力学建构了泥石流最大抛程计算理论。 相似文献
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Janić Milan 《运输规划与技术》2013,36(3-4):301-318
The paper presents a model for determining the practical capacity of a single track line, i.e. the maximum number of trains which can be run along it in a time unit under the condition that each train enters its bottleneck segment with a definite delay. The input data used in the model are: geometrical characteristics of the bottleneck segment of the line under study, the intensity and structure of demand expressed by a number of trains which are run over the line in a given time unit, the scenario of traffic running over the line under study and the operational tactics of individual train categories processing on the bottleneck segment. (Two tactics can be applied in the train processing on the line under study; first, the trains of individual categories are given different priorities in the processing, and second, all the trains have the same priority). The output results of the model are average delays of trains of each category occurring within the train processing performed on the bottleneck segment of the line under study in a given time unit. 相似文献
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When passenger terminal layout is being decided, one of the important aspects to consider is how the passenger orients himself during his visit to the terminal and his movements through it, i.e. terminal orientation. Among other things, this terminal characteristic results from visibility, or the visual connectivity between elements and spaces. The paper proposes an amendment and modification to the known method for the quantitative evaluation of terminal orientation which uses an oriented network to describe the connectivity of elements (terminal orientation). The amendment and modification of the method consists of proposing that during evaluation only visual connections that have functional meaning should be considered, rather than all visual connections. A further modification is the introduction of different weights for different connections. The example presented in the paper considers an airport terminal building. 相似文献
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周丽 《上海交通大学学报(哲学社会科学版)》2000,8(1):89-91,110
本文对企业研究与开发费用的现行会计处理方法,即全部费用化和部分资本化作了分析,并指出了这两种处理方法存在的缺点。提出了在知识经济时代,随着企业研究开发费用投入的不断增加,对研究开发费用的会计处理应采用全部资本化处理方法的观点。 相似文献
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重点建设项目的社会稳定风险分析和评估(简称稳评)是上海近年新开展的一项工作,通过对该项工作的主要目的、原则及过程进行研讨,利用开创性的社会学研究方法,将工程客观影响特点及相关特性调查有机结合,经归纳分析,预测项目可能产生的社会稳定风险.众多重大市政项目的稳评实践结果表明,所采用的方法可靠,评估结论准确可信,能为今后其他项目的分析和评估工作提供指导与参考,发挥稳评从源头上避免和减少因工程建设引发社会矛盾的积极作用. 相似文献
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Milan Janić 《运输规划与技术》2013,36(6):569-592
This paper investigates the potential of Light Rail Rapid Transit (LRRT) to mitigate the environmental and social burden of ground access systems of an airport. This implies, on the one hand, LRRT's capability in mitigating externalities in terms of noise, air pollution/climate change, traffic incidents/accidents and congestion of airport ground access systems and, on the other, the provision of sufficient capacity to accommodate generally increasing volumes of both air passenger and airport employee demand by connecting the airport to its core catchment area. A methodology for assessing the capability of LRRT operating as an airport ground access system is developed. This methodology consists of models to analyze and predict demand and capacity for an LRRT system and models to quantify the externalities of particular airport ground access systems as well as assessing their prospective savings thanks to the introduction of an LRRT system. The methodology is applied to a large European airport – Amsterdam Schiphol (the Netherlands) – using a ‘what-if?’ scenario approach. 相似文献
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The purpose of this paper is to implement an efficient method for GIS‐based traffic analysis zone (TAZ) design in order to evaluate and validate such a method. The method was developed by the authors. Moran's I spatial autocorrelation coefficient and sample variance are used for evaluating the generated TAZs using the Champaign‐Urbana, IL region as a case study. Sensitivity analysis is also conducted to explore the fluctuations in TAZ generation outcomes. The evaluation, the validation as well as the TAZ design have been implemented with ARC/INFO GIS software on a UNIX workstation platform. 相似文献