给水集中监控系统建设及测试评定标准的制定与完善

根据国内外给水自动化的发展趋势和铁路改革前进的要求，认为实现铁路给水集中监控势在必行；鉴于给水集中监控初始发展的巨大差异和理论的不成熟，提出了制定和完善给水集中监控系统建设和测试评定标准的必要性，并就2个标准的组成框架和分部内涵进行了全面阐述；同时又指出，由于监控系统的初始建设和标准的第一次出台，均需在实践中尽快发展与完善。     

气压防抱死制动系统电磁阀的性能评价方法

分别从整车设计和零部件本体两个角度对防抱死制动系统电磁阀的性能评价进行阐述,从公司对产品的评价方法和实际经验数据当中总结归纳评价方法,并提出相应的评价指标。     

套箍法加固石拱桥主拱圈的正截面承载力的理论分析

针对石拱桥拱圈加固后的正截面承载力计算问题,提出了考虑加固前截面受力状况及加固材料不同力学性能的计算方法。对加固后的拱圈进行应力应变分析,得出界限破坏的3种形式,对每种界限破坏形式利用截面的协调变形和截面材料的应力应变关系,分析了其极限状态时组合截面的相对界限受压区高度,得出加固后石拱圈最后的破坏模式主要与加固前的初应变及加固层的厚度有关。对应于3种破坏形态从理论上推导出套箍法加固石拱圈在二次受力时的正截面承载力计算公式。计算公式充分考虑了加固前的构件应力水平、加固后截面不同材料组成及构件破坏形态的影响,比现有加固规范的计算取值更趋于合理,为同类加固结构的设计和计算提供了依据。     

隧道火灾后结构物快速检测评估及处治设计分析

以京珠高速公路大宝山隧道火灾后结构物损伤为研究对象,重点分析隧道内发生火灾后,对隧道损伤部分进行快速检测的内容及其方法。根据检测结果,科学合理评估火灾烧损等级,制定快速又合理的加固设计方案,并结合营运3年的检查情况,认为处治设计方案科学合理,达到了预期的加固效果。     

朝阳洲地区路基处治措施及评价

道路工程中遇到不良路基时必须经过相应的技术措施处理才能达到技术标准。分析南昌市朝阳洲地区高含水量路基对道路工程的影响,提出不良路基处理的一般技术措施及其注意事项。     

软土路基安全性评价专家系统研究

根据软土路基的特点,考虑建模过程的系统全面性、简明科学性、相对独立性及灵活可操作性,选取合理的路基安全性评价指标,用层次分析法确定评价指标的权重矩阵,采用模糊综合评判方法建立软土路基安全性评价分级模型,并建立专家系统,应用专家系统对唐山市滨海大道的路基安全性进行评价。结果表明,此模型和专家系统能很好地反映软土路基的安全性状况,具有合理性和实用性,可供同类工程借鉴。     

大跨度外倾式拱桥稳定及极限承载力分析

为研究外倾式拱桥稳定及极限承载力问题,以九堡大桥为背景,建立有限元分析模型,分别计算了该桥线性屈曲、几何非线性稳定(分别考虑初始缺陷以及材料非线性)、弹塑性稳定状态下的稳定系数,对失稳机理以及车道荷载和静风荷载作用下的极限承载力进行分析,在此基础上讨论了荷载及横撑布置对极限承载力的影响。分析结果表明:几何非线性对于刚度较大的钢拱桥稳定的影响不大,而材料非线性对极限承载力的影响显著,弹性稳定分析会过高地估计钢拱桥的极限承载力;外倾式拱桥的失稳多为面外失稳形式,且副拱拱顶横撑对稳定的影响较小。     

顺置式吊杆锚固区受力特性与极限承载力研究

为掌握顺桥向设置的吊杆锚固区在吊杆力作用下的受力特性和极限承载力,以某在建斜拉-自锚式悬索组合体系桥为依托工程,利用ANSYS软件建立壳单元空间有限元模型,对锚固区在最不利荷载作用下的受力性能进行研究;并分别采用线弹性及非线性分析方法对吊杆锚固区极限承载力进行分析,讨论构件的受力情况。结果表明:在最不利荷载作用下,钢锚箱及钢锚梁应力较横隔板应力小;除钢锚梁与横隔板焊接处应力集中现象显著外,各构件应力分布较均匀;各构件顺桥向变形较大。不同极限承载力分析方法表明,此类结构采用壳单元建模进行极限承载力分析时应仅考虑材料非线性。建议在此类结构设计时,对于横隔板刚度不足问题应给予足够重视。     

高速公路改扩建作业区的合理布设

目前我国相关规范并没有对高速公路改扩建作业区的布设做出相应的规定,施工中的一些不合理设置大大降低了作业区的通行能力和运行效率,并且存在诸多安全隐患。针对这一问题,运用交通仿真技术对双向四车道高速公路基本路段的通行能力以及作业区各主要控制区段（如预告段、合流段等）的长度进行研究分析,得到高速公路改扩建期作业区的长度设置标准和布设要求,为今后高速公路改扩建工程作业区的设置提供参考。     

Do driver training programs reduce crashes and traffic violations? — A critical examination of the literature

This paper reviews the evaluation literature on the effectiveness of classroom and behind-the-wheel driver training. The primary focus is on North America programs as originally taught in high schools but now also by private instructors. Studies from the United Kingdom, Australia, New Zealand and Scandinavia are also included.By far the most rigorous study to date was the experimental study in DeKalb, Georgia, U.S.A. This study used a randomized design including a control group and a very large sample size to provide reasonable statistical precision. I reexamine the DeKalb data in detail and conclude that the study did show evidence of small short-term crash and violation reductions per licensed driver. However, when the accelerated licensure caused by the training is allowed to influence the crash and violation counts, there is evidence of a net increase in crashes.The other studies reviewed present a mixed picture but the better designed quasi-experimental evaluations usually showed no effects on crash rates but almost all suffer from inadequate sample size. I show that as many as 35,000 drivers would be required in a two group design to reliably detect a 10% reduction in crash rates.The advent of GDL laws in North America and other countries has largely remedied the concern over accelerated licensure of high risk teenage drivers by delaying the progress to full licensure. Conventional driver training programs in the U.S. (30 h classroom and 6 h on-the-road) probably reduce per licensed driver crash rates by as little as 5% over the first 6-12 months of driving. The possibility of an effect closer to 0 cannot be dismissed.Some GDLs contain an incentive for applicants to complete an advanced driver training program in return for shortening the provisional period of the GDL. The results of Canadian studies indicate that any effects of the driver training component are not sufficient to offset the increase in accidents due to increased exposure.There is no evidence or reason to believe that merely lengthening the number of hours on the road will increase effectiveness. Programs directed toward attitude change and risk taking better address the underlying cause of the elevated crash risk of young drivers but these behaviors are notoriously resistant to modification in young people.