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761.
针对省道103高速公路上的大桥均采用等跨径、等截面的连续箱梁形式,施工工艺采用先简支、后连续的方法,文章就其体系转换过程介绍了先简支、后连续的受力原理及其施工工艺。 相似文献
763.
764.
通过参数分析,探讨曲线桥梁支座布置、平面圆心角和曲率半径对其抗倾覆稳定的影响.结果表明:中墩采用双支座、减少单联桥梁圆心角,能有效改善曲线桥梁的抗倾覆稳定性能;当圆心角φ<34°时,抗倾覆稳定系数趋于稳定. 相似文献
765.
简要介绍了潜艇通信天线的技术特点和发展趋势,并结合几种潜艇通信天线的现状对潜艇通信天线的选用及需要考虑的主要问题进行了综述.另外,还介绍了国外发展的相关情况,并就目前我国潜艇通信天线需重点解决的问题提出了看法. 相似文献
766.
针对深圳地铁3号线轨排井基坑施工中预应力锚索存在的安全隐患,考虑设计中的钢花管施工难度较大等原因,结合实际揭露地层,利用有限差分分析程序FLAC3D进行优化设计。结果表明,优化后基坑围护结构的各项性能指标均能满足设计要求,轨排井得以顺利安全施工,节省人力物力,方便施工,缩短工期。 相似文献
767.
Complexity of car park activity is reproduced from a concurrent execution of behaviour of various drivers. This paper presents a step in the development of a multimodal traffic simulator based on multi‐agent paradigm and designed as a decision aid tool as well as a video game. The user‐player has the opportunity to test different scenarios. We propose an approach for designing the decision‐making rules and the learning mechanism for a car driver agent. For that, a panel of methods such as stated preference modelling, Design Of Experiments and data fusion is used. Initial behavioural models, based on similar preferences, are developed for specified categories. Each agent will adapt its behaviour after executing its learning process. Our approach can be used in order to optimize needs of road network users and those of people in charge of traffic regulation. A demonstrator has been developed to test parking policies in an urban area as well as changes of car park characteristics. 相似文献
768.
《铁道标准设计通讯》2016,(2):113-118
暗挖地铁车站断面较大,通常埋深较浅,施工时常发生塌方事故,且塌方纵向影响长度多达数十米。为提高塌方后续施工的安全性,结合塌方事故实例,利用风险分析和有限元计算方法,并结合现场监控量测数据,研究塌方事故影响段后续施工问题。研究结果表明:在后续施工中采用双侧壁导坑法安全可靠,"变大跨为小跨"有效控制后续施工引起的变形;从施工工法、支护措施及施工工艺等多方面制定措施,改善岩体物理性能,提高支护体系和围岩承载能力,有效控制后续施工风险。 相似文献
769.
Efficiency in the operation of the Swedish motor-vehicle inspection monopoly was examined by analyzing data on all decision-making units related to production of inspection services during 1993. In addition, theoretically based arguments concerning some regulation problems are discussed. The results imply a fairly high level of technical efficiency, which might be explained by the extensive practice of yardstick-competition in the industry. The findings, based on a best-practice approach, do not indicate strong empirical evidence in support of a deregulation of the industry. However, the regulation problems discussed may provide motives for deregulation. 相似文献
770.
Productivity,efficiency and technical change in the European railways: A non-parametric approach 总被引:2,自引:0,他引:2
The purpose of this paper is to analyse the evolution of productivity in the European railways in the period 1970–95. We use
a non-parametric approach that enables changes in productivity to be broken down into variations in efficiency and technical
change. The results indicate that the productivity growth is concentrated in the last period (1985–95), when the majority
of the companies undertook processes of reforms. This increase in productivity is mainly due to technical progress. We also
analyse the determinants of efficiency and, unlike other papers, the technical change, finding that the greater the degree
of autonomy and financial independence, the higher the efficiency levels and technical change.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献