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21.
文章分析了锚杆拉拔试验的结果,提出了非全长粘结型锚索锚固段剪应力沿长度分布的二次抛物线模式,以及确定锚固段长度的合理方法,并以工程实例说明了文中提出的锚索锚固段长度计算方法的合理性. 相似文献
22.
文章主要介绍基于UG二次开发的DTS名义值测量,本系统基于西门子的先进CAD设计平台NX之上开发的系统。以NX11和Visual Studio 2010作为运行和开发平台的,C、C++为开发语言,使用Block UI Styler为界面设计工具,NXOpen则提供了开发所需的应用程序包(API)。系统可以通过获取整车FVML(Finish Vehicle Measurement Location)文件包含的信息,通过用户选择文档中对应的零件特征,实现自动测量数模名义值及对应截面,并与FVML定义的数值进行对比。 相似文献
23.
Wang J.Ji X. 《现代隧道技术》2018,(6):11-18
Jacking force is the most important parameter in jacking pipe engineering, and reasonable calculation of jacking forces plays an important role in safe and smooth pipe jacking construction. There are many calculation methods for pipe jacking force at present, and the calculation results may be affected to some extent by different cal⁃ culation methods. For this reason, calculation methods of jacking force (frictional resistance) were collected and a comparative analysis was conducted with aspects to the advantages, disadvantages and applicabilities. The results show that as for the jacking force calculated by empirical formulae, the soil layer classifications corresponding to giv⁃ en frictional force per unit area and relevant factors to be considered are different, and the values of frictional force per unit area between pipe and soil in the same soil layer are also different; as for the jacking force calculated by theo⁃ retical formulae, the calculation methods for vertical earth pressure at crown are different and much effected by the pipe buried depth; as for the jacking force calculated by numerical simulation, the selected theories for the simula⁃ tion program and the construction factors to be considered during simulation are different. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献
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Understanding the patterns of automobile travel demand can help formulate policies to alleviate congestion and pollution. This study focuses on the influence of land use and household properties on automobile travel demand. Car license plate recognition (CLPR) data, point-of-interest (POI) data, and housing information data were utilized to obtain automobile travel demand along with the land use and household properties. A geographically and temporally weighted regression (GTWR) model was adopted to deal with both the spatial and temporal heterogeneity of travel demand. The spatial-temporal patterns of GTWR coefficients were analyzed. Also, comparative analyses were carried out between automobile and total person travel demand, and among travel demand of taxis, heavily-used private cars, and total automobiles. The results show that: (I) The GTWR model has significantly higher accuracy compared with the Ordinary Least Square (OLS) model and the Geographically Weighted Regression (GWR) model, which means the GTWR model can measure both the spatial and temporal heterogeneity with high precision; (II) The influence of built environment and household properties on automobile travel demand varies with space and time. In particular, the temporal distribution of regression coefficients shows significant peak phenomenon; and (III) Comparative analyses indicate that residents’ preference for automobiles over other travel modes varies with their travel purpose and destination. The above findings indicate that the proposed method can not only model spatial-temporal heterogeneous travel demand, but also provide a way to analyze the patterns of automobile travel demand. 相似文献
25.
高寒隧道保温设计研究及热工计算方法初探 总被引:1,自引:0,他引:1
目前国内高寒隧道研究成果还不能完全满足隧道设计要求,文章借鉴我国建设部房建行业和日本国铁的研究成果,提出了适用于季节性冻土隧道洞口保温段长度、衬砌保温及水沟保温的设计计算方法。 相似文献
26.
文章分析了震后城市交通系统通行性的影响因素,提出了包含路段单元通行概率、路段连通概率及路网连通概率的城市交通系统通行性计算理论,为城市路网的连通可靠性评价提供参考。 相似文献
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文章以汽车运用与维修技术专业为例,分析该专业的实训资源在1+X证书制度实施过程中存在的问题,提出实训资源优化整合建设的必要性.依据《汽车运用与维修(含智能新能源汽车)职业技能领域职业技能等级标准》设计出汽车运用与维修技术专业实训资源优化整合建设架构图,并对实训资源优化整合建设给出了详细的方案. 相似文献
30.
轮边驱动电机采用轮毂电机,实现四轮独立驱动,方便汽车动力学性能的控制.对于电动客车,轮边电机驱动以其轻量化、传递效率高等优势正在取代中央直驱的方式,成为现在研究的热点.这种驱动方式取消了离合器和变速器等,驱动电机安装在车轮旁边,结构空间和重量得以大幅度降低电.文章以四轮独立驱动的轮毂电机电动客车为研究对象,通过驱动转矩... 相似文献