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0引言在以水泥稳定碎石为基层的沥青路面中,基层是主要的承重层。在车辆荷载的反复作用下,若面层较薄且面层与基层间粘结不好时,易使基层材料产生疲劳破坏。此外,考虑到水泥稳定碎石的抗压性能远优于其抗拉性能,虽然车辆荷载的一次作用引起的基层底部拉应力较小,但在荷载反复作用下仍然会导致基层疲劳开裂,故有必要研究其抗拉疲劳性能。本文借助灰色关联分析方法,对水泥稳定碎石混合料的应力水平、水泥剂量、4.75mm通过率、成型方式及抗弯拉强度等影响因素进 相似文献
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水泥乳化沥青混合料是一种强度高、密实度大的优异材料,文章对其高低温性能展开了研究,以水泥、沥青、纤维三个影响因素设计正交试验,通过对混合料的抗压试验、高温车辙试验、低温抗裂试验得到水泥、沥青、木纤维最佳的设计掺量.试验结果表明:当水泥、沥青、纤维用量分别取3.5%、3.5%、0.4%时,水泥乳化沥青混合料的抗压、抗剪性... 相似文献
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水泥稳定碎石基层的干缩特性是其最重要的路用性能之一,关系着路面的使用寿命.文章通过试验研究了集料级配、水泥剂量、含水量、压实度等因素对水泥稳定碎石基层干缩特性的影响,为其施工质量控制提供参考依据. 相似文献
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大厚度半刚性基层层间结合技术室内试验研究 总被引:1,自引:0,他引:1
文章通过室内直剪试验,对大厚度水泥稳定碎石基层上下层结合状态进行研究,分析了大厚度水泥稳定碎石基层上下层浇筑间隔时间、养生时间及水泥浆用量对层间抗剪性能的影响,并提出了最佳施工工艺。 相似文献
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本文针对厚层水泥稳定碎石在使用过程中暴露出的问题进行调研,发现基层层间状态是导致诸多病害的原因,通过软件计算不同层间状态下基层的受力特性,提出改善施工工艺、重视路面防水和排水、提高抗裂性能三种解决措施,希望为以后的相关研究提供借鉴和参考。 相似文献
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结合高等级公路水泥稳定碎石基层开裂的破坏现状,在调研国内外已有研究成果的基础上,通过掺加SBR胶乳改性剂对水泥稳定碎石材料的开裂性能进行改善,通过试验研究其抗开裂性能,使之减少或延缓水泥稳定碎石基层裂缝的发生,充分发挥水泥稳定碎石基层路用性能的优势,延长道路使用寿命。 相似文献
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Pedestrians as compared to vehicular traffic enjoy a high degree freedom of movement even in heavily congested areas. Consequently, there are more alternative links available to pedestrians between a given origin‐destination (O‐D) pair. This paper describes a study done by the University of Calgary to evaluate the factors affecting the choice of route on intra‐CBD trips or trips within the Central Business District (CBD). An origin destination survey conducted in downtown Calgary, Alberta enabled the identification of the most significant factors influencing the choice. These factors were analyzed in relation to the physical characteristics of the location, personal characteristics of the trip maker and the type of the trip. It appears that most people chose the shortest link and factors such as the level of congestion, safety or visual attractions were only secondary. This suggests that the length should be made a major consideration when planning and designing pedestrian links. 相似文献
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《Transportation Research Part A: General》1991,25(6):407-418
The main deficiency of most current modeling approaches to transportation can be identified as neglect of the integration of existing geographical knowledge in regard to the ex ante transport/land use modeling approaches, with its focus on territorial dynamics and theory development. This paper addresses this aspect of the problem by introducing a theoretical and methodological framework for the analysis of the interrelationship between land uses. The analysis attempts to determine to what extent the functional land use in a city can be considered an ordered pattern. The order sought does not rely on purely spatial configurations, but on the correlation of transportation and land use. The first section of this paper focuses on theoretical considerations. It stresses the fact that conventional approaches do not apply in the present context. It then suggests an alternative based on areas of influence and measured in terms of level of attractance of land uses. The second describes a procedure based on this alternative following the remarkable contribution of Hanjoul, Beguin and Thill. An application of this procedure to the analysis of Shanghai is then examined. Finally, an evaluation of the strategies for optimizing the interrelationship between land uses is presented. The paper concludes with a possible research agenda. 相似文献
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明确埋地管道防腐保温层的技术评价标准,对埋地钢质管道的安全运行,延长管道使用寿命具有重要意义。为了对埋地管道防腐保温层做出有效评价,从间接检测与开挖检测2个方面,结合现场检测数据,提出了基于防腐保温层的电流衰减率、绝缘电阻率、质量状况与厚度的分级评价标准及基于4种评价指标的综合评判方法。工程实践表明,该评价标准对防腐保温层是否存在失效能做出有效判断。 相似文献
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介绍了城市轨道交通工程中杂散电流不同的监测系统的构成,分析了集中式、分散式和智能型等监测系统的配置和功能,以及智能型实时在线监测系统的重要意义,为轨道交通工程杂散电流监测系统的选择与应用提供参考。 相似文献
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天然气自动计量系统有多种组态软件,由于软件的不相通性,造成了计量系统数据采集的通用性差、数据传输与入库的时效性差、数据利用的可靠性低.结合各组态软件的实际情况,从设计上充分利用Oracle大数据处理能力以及Partition(分区表)的特性,实现历史数据的存储,应用WebService与COM+数据访问组件提供多层数据访问架构,采用OPC与DDE工业数据交换协议,实现了各站场计量数据的实时上传,为连续数据采集和实时监控提供了可能,节约了改造成本. 相似文献
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Joseph N. Prashker 《Transportation》1979,8(4):329-346
Reliability of travel modes was found to be the most important characteristic of transportation systems in several attitudinal investigations of individual travel behavior. This paper represents the first part of a research effort aimed at gaining a better understanding of the characteristics of reliability of transportation modes in urban travel. In this research, reliability characteristics are identified; their importance relative to each other is assessed, and an insight into possible structure of an objective reliability index is discussed. The research is based on perceived values of reliability, which were identified through a large attitudinal survey conducted in the Chicago metropolitan area. 相似文献
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