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861.
采空区是隧道施工的一大难点,其处理技术及其安全措施实施的好坏直接影响到隧道施工及运营安全。以水塘隧道施工为例,结合该隧道采空区的特征,介绍了采空区的处理方法及所采取的安全防护措施,以供同类工程施工参考。 相似文献
862.
针对桂林市道路交通安全形势严峻的问题,采崩系统工程的方法对桂林市交通事故多发现象进行因果关系分析。以此为基础,借鉴香港的道路交通经验,并结合桂林市的实际,提出桂林市道路交通安全改善策略。运用高科技提高道路监管水平;加强管理,提高汽车安全性能;提高道路规划设计水平,改善道路条件;创造交通安全文化,提高人们的道路交通安全意识。 相似文献
863.
Safety modeling for two‐way left‐turn lanes and a procedure to identify two‐way left‐turn lane segments with safety concerns
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In the past, two‐way left‐turn lane (TWLTL) median treatments have been frequently used in Florida to inexpensively improve traffic and safety performances. In order to identify factors that may have significant impacts on safety operations in TWLTL sections and to identify TWLTL locations that present existing and future safety concerns, a research project was carried out and results are summarized in the paper. In the research, a three‐year crash history database with crashes and section characteristics from a total of 1688 TWLTL sections all over Florida was developed and used. A negative binomial regression model was developed to determine the statistical relationship between the number of crashes per mile per year and several variables such as traffic volume, access density, posted speed, and number of lanes. In regard to the methodology, in order to identify locations with safety concerns, several steps are needed: development of real crash data distribution, determination of statistical distribution models that better represent the actual crash data, determination of percentile values for the average number of crashes, estimation of crash rates for sections with the same characteristics, estimation of critical values for the variables corresponding to the percentile values for average number of crashes, calculation of tables of critical average annual daily traffic values, and generation of a list of TWLTL locations with critical safety concerns. Results presented in the paper have been used in real applications. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
864.
介绍长江口新一代车客渡船的设计特点,包括:节能效果显著的非对称双尾鳍船型;富有个性的新颖船舶外观造型;以及既经济实用又能体现时代气息的舱室装潢设计。 相似文献
865.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(10):1233-1253
Previously, a new control concept called ‘G-vectoring control (GVC)’ to improve vehicle agility and stability was developed. GVC is an automatic longitudinal acceleration control method that responds to vehicle lateral jerk caused by the driver's steering manoeuvres. In this paper, a new yaw-moment control method, which generates a stabilising moment during the GVC command and has positive acceleration value and the driver's accelerator pedal input is zero, was proposed. A new hybrid control, which comprises GVC, electric stability control and this new control, was constructed, and it was installed in a test vehicle and tested on a snowy surface. The very high potential for improvement in both agility and stability was confirmed. 相似文献
866.
以武咸城际铁路连续梁转体上跨武广高铁施工安全防护为实例,阐述了施工方案优化在规避施工风险中的突出作用,分析了施工面临的主要风险因素和对策措施,介绍了各防护类型及其防护对象、现场操作要点,指出了各种防护类型的利弊,有效地解决了连续梁上跨高铁线路施工防护难题。 相似文献
867.
结合兰渝铁路西秦岭隧道TBM项目刀具的使用、维修、更换等过程,分析刀具检查与维修的工艺过程,对刀具拆卸检查与维修中的各注意事项进行总结。刀具的检查与维修在掘进过程中占有一定的比例,保证刀具检修的质量是TBM快速掘进的前提,刀具的使用寿命会影响TBM掘进的利用率。西秦岭TBM项目针对不同地质情况下的施工刀具维修制定了详细的检查项目,经过第1阶段刀具检查维修的实践,取得较好的成效。 相似文献
868.
Risk-based inspection is nowadays the predominant approach to structural integrity assurance in complex engineering systems, such as those designed for and operated in deepwater environments. One of the major tasks in risk-based planning is risk ranking of the components comprising an engineering system. In this paper, a mathematical model based on data envelopment analysis is developed for this purpose, whereby two types of weights are employed: subjective judgmental weights which are provided as input, and objective which constitute the output of the model. The use of the mathematical model is illustrated in a real world system of subsea flexible pipes, which operational in the south Atlantic Shelf off the Southeast Coast of Brazil. 相似文献
869.
870.