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151.
文章结合高速公路U型桥台开裂的典型工程实例,分析了U型桥台裂缝产生的原因,提出了相应的加固处治方案,并阐述了加固方案的实施要点与处治效果。 相似文献
152.
文章介绍了采用免棱镜全站仪进行旧桥几何尺寸测量的主要内容、优点、测点布置情况及方法,并结合具体工程实例,探讨了免棱镜全站仪的使用效果。 相似文献
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Shared autonomous vehicles, or SAVs, have attracted significant public and private interest because of their opportunity to simplify vehicle access, avoid parking costs, reduce fleet size, and, ultimately, save many travelers time and money. One way to extend these benefits is through an electric vehicle (EV) fleet. EVs are especially suited for this heavy usage due to their lower energy costs and reduced maintenance needs. As the price of EV batteries continues to fall, charging facilities become more convenient, and renewable energy sources grow in market share, EVs will become more economically and environmentally competitive with conventionally fueled vehicles. EVs are limited by their distance range and charge times, so these are important factors when considering operations of a large, electric SAV (SAEV) fleet.This study simulated performance characteristics of SAEV fleets serving travelers across the Austin, Texas 6-county region. The simulation works in sync with the agent-based simulator MATSim, with SAEV modeling as a new mode. Charging stations are placed, as needed, to serve all trips requested (under 75 km or 47 miles in length) over 30 days of initial model runs. Simulation of distinctive fleet sizes requiring different charge times and exhibiting different ranges, suggests that the number of station locations depends almost wholly on vehicle range. Reducing charge times does lower fleet response times (to trip requests), but increasing fleet size improves response times the most. Increasing range above 175 km (109 miles) does not appear to improve response times for this region and trips originating in the urban core are served the quickest. Unoccupied travel accounted for 19.6% of SAEV mileage on average, with driving to charging stations accounting for 31.5% of this empty-vehicle mileage. This study found that there appears to be a limit on how much response time can be improved through decreasing charge times or increasing vehicle range. 相似文献
155.
ABSTRACTThis paper describes the development of railway station choice models suitable for defining probabilistic station catchments. These catchments can then be incorporated into the aggregate demand models typically used to forecast demand for new rail stations. Revealed preference passenger survey data obtained from the Welsh and Scottish Governments was used for model calibration. Techniques were developed to identify trip origins and destinations from incomplete address information and to automatically validate reported trips. A bespoke trip planner was used to derive mode-specific station access variables and train leg measures. The results from a number of multinomial logit and random parameter (mixed) logit models are presented and their predictive performance assessed. The models were found to have substantially superior predictive accuracy compared to the base model (which assumes the nearest station has a probability of one), indicating that their incorporation into passenger demand forecasting methods has the potential to significantly improve model predictive performance. 相似文献
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�й����ܽ�ͨϵͳ��չս���о� 总被引:7,自引:0,他引:7
概要地介绍了“十五”国家科技攻关计划项目“中国智能交通系统发展战略研究”的主要内容和结论,该研究站在全局的高度,围绕国家综合交通的发展目标,深入地分析了我国交通运输的需求和必须解决的重大问题,客观评价了国际和国内智能交通的发展水平以及我国的差距,提出未来10~15年我国智能交通发展的指导思想、战略目标、各阶段的重点战略目标及保障措施和建议等。课题的研究成果将为编制我国智能交通的发展规划提供科学依据。 相似文献
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从污水处理工艺选择和污水处理设备管理两个方面阐述了当前国内高速公路服务区污水处理现状,旨在为服务区的污水处理方式和管理提供参考。 相似文献