共查询到20条相似文献,搜索用时 343 毫秒
1.
结合x实际工程,首先对灌砂法、环刀法、核子密度仪法、落锤频谱式路基压实度快速测定仪四种路基压实度试验检测技术进行对比分析,重点对灌砂法检测技术进行研究,研究结果证实,采用合理的压实度试验检测技术可有效提高公路路基质量,可为同类路基压实度试验检测技术应用提供借鉴和参考. 相似文献
2.
3.
为探讨公路路基压实度试验与检测方法,本文采用理论结合实践的方法,立足公路路基压实度检测的标准要求,分析了公路路基压实度试验要点和常用的检测方法,并提出提升路基压实度检测方法应用效果的措施.压实度是衡量公路路基施工质量的主要指标,采取科学合理的试验与检验方法,可提升公路路基压实度检测的准确性和效率,保证公路路基的总体质量符合要求. 相似文献
4.
5.
近几年来,随着国家对基础设施投资力度的加大,高速公路建设也进入了快速发展时期,如何控制砂性土路基压实度成为路基施工质量控制的重点。在阐述砂性土力学性质的基础上,探讨了砂性土路基压实度的控制方法及注意事项,可为相关施工提供参考。 相似文献
6.
介绍了我国公路改扩建工程的发展现状及技术难点,然后对山西某公路改扩建工程采用土工格栅固定、块石锁嵌以及喷射砂浆加固的方法增强粘结力以及路基整体性,从而保证压实效果;再利用厂拌冷再生铺筑新老路基共同作用层,分散传递荷载应力。最后用灌砂法测定新老路基压实度;贝克曼梁法检测弯沉来评价路基稳定性。结果表明,这种技术处理后的路基衔接紧密,同一横截面新老路基压实度差值均小于1%,弯沉相差小,路基整体性良好。 相似文献
7.
为保证公路工程路基压实度达标,对影响路基压实度的各种因素进行分析,介绍环刀法、灌砂法、核子密度仪法等常见路基压实检测技术,并总结提升路基压实度检测效果的建议,以期有效提高公路工程施工质量,达到改善道路运营状态的目的。 相似文献
8.
9.
膨胀土路基因其特殊性,在干湿循环作用下易产生不均匀变形和路基病害,严重威胁高速公路的运营安全。文章通过某公路路段膨胀土路基的模型试验,得到了膨胀土路基压缩沉降变形、侧向塑性变形以及水分运移和干缩变形的规律,并提出控制膨胀土路基变形的措施,结论如下:(1)路基压缩沉降与上覆荷载、饱和度、压实度有关,路基变形中的塑性变形阶段对路基侧向变形有重要影响,膨胀土的干缩变形与其中的水分运移有关;(2)由试验结果得出的路基填料的最佳压实度、饱和度分别为93%、90%,因此,为控制路基变形应将填料含水率控制在天然含水率以下,同时提高压实效果;(3)应从填料选择、填筑质量及防排水措施三方面控制和处理膨胀土路基。 相似文献
10.
11.
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
12.
This paper estimates the efficiencies and productivity changes of 12 international airports in the Asia-Pacific region based on data from 1998 to 2006. We apply stochastic frontier analysis (SFA) to compute efficiency estimates and use the Malmquist productivity index (MPI) to analyze productivity changes. We use the SFA model with a translog-type production function after testing the statistical hypotheses. According to the results of the SFA hypothesis tests, airports have experienced a technological regression; the deviations from the efficiency frontier are caused more by technical inefficiency than random noise. However, the inefficiency was found to decrease. The MPI reveals a declining trend resulting more from technological change than from efficiency change, with a decrease in inefficiency. Taken together, both the hypothesis tests and the MPI not only provide consistent conclusions, but also suggest that airports should concentrate on technological progress. 相似文献
13.
14.
15.
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
16.
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
17.
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
18.
《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
19.
20.
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