高等级公路沥青路面的质量监督与控制技术

本文依托沪渝国道主干线支线分水岭(鄂渝界)至忠县高速公路(以下简称石忠路)工程的施工质量监控项目,介绍了沥青路面质量监控的主要内容,以及一些好的技术措施,并针对出现的问题,提出相应的处理办法。     

谈公路施工企业项目管理中存在的问题及对策

针对公路施工企业项目管理的复杂性和风险性,总结了目前公路施工企业项目管理中存在的问题,提出了应对策略并进行了系统分析,从而使企业项目管理水平不断提高,实现项目利润最大化。     

公路挡土墙受力分析

针对公路挡土墙进行了受力分析,以夯锤冲击力作为研究对象,结合碰撞理论,探讨了挡土墙受冲击应力、侧压力的计算方法,并利用计算机进行了程序计算,从而降低了成本,提高了工作绩效,为公路挡土墙受力分析提供了新思路。     

公路工程混凝土质量通病防治研讨

为了解决公路工程混凝土质量通病问题,从管理和施工工艺等方面对各种质量通病产生的原因进行了详述,并提出了解决办法,达到了提高混凝土结构工程的耐久性和安全性的效果。     

沥青拌和站油改煤应用技术分析

针对沥青拌和站在连霍公路甘肃段嘉安路面二标施工中燃油改煤成套技术的应用及可行性等进行了分析,具体阐述了煤粉燃烧装置的组成及工作原理,结合实际应用产生的经济效益,指出该技术技巧性很强但效果显著,值得推广。     

沥青路面典型预养护技术措施研究

在借鉴国外预养护技术的基础上，根据我国沥青路面的特点和养护技术现状，推荐稀浆封层等7种技术措施作为我国沥青路面典型预养护对策，并就这些措施的技术特点、功能与适用条件进行了深入的分析与系统的总结，从而推广这些预养护技术的应用。     

Road crash fatality rates in France: A comparison of road user types,taking account of travel practices

Background

Travel practices are changing: bicycle and motorized two-wheeler (MTW) use are rising in some of France’s large cities. These are cheaper modes of transport and therefore attractive at a time of economic crisis, but they also allow their users to avoid traffic congestion. At the same time, active transport modes such as walking and cycling are encouraged because they are beneficial to health and reduce pollution. It is therefore important to find out more about the road crash risks of the different modes of transport. To do this, we need to take account of the number of individuals who use each, and, even better, their travel levels.

Method

We estimated the exposure-based fatality rates for road traffic crashes in France, on the basis of the ratio between the number of fatalities and exposure to road accident risk. Fatality data were obtained from the French national police database of road traffic casualties in the period 2007–2008. Exposure data was estimated from the latest national household travel survey (ENTD) which was conducted from April 2007 to April 2008. Three quantities of travel were computed for each mode of transport: (1) the number of trips, (2) the distance traveled and (3) the time spent traveling. Annual fatality rates were assessed by road user type, age and sex.

Results

The overall annual fatality rates were 6.3 per 100 million trips, 5.8 per billion kilometers traveled and 0.20 per million hours spent traveling. The fatality rates differed according to road user type, age and sex. The risk of being killed was 20 to 32 times higher for motorized two-wheeler users than for car occupants. For cyclists, the risk of being killed, both on the basis of time spent traveling and the number of trips was about 1.5 times higher than for car occupants. Risk for pedestrians compared to car occupants was similar according to time spent traveling, lower according to the number of trips and higher according to the distance traveled. People from the 17–20 and 21–29 age groups and those aged 70 and over had the highest rates. Males had higher rates than females, by a factor of between 2 and 3.

Conclusion

When exposure is taken into account, the risks for motorized two-wheeler users are extremely high compared to other types of road user. This disparity can be explained by the combination of speed and a lack of protection (except for helmets). The differential is so great that prevention measures could probably not eliminate it. The question that arises is as follows: with regard to public health, should not the use of MTW, or at least of motorcycles, be deterred? The difference between the fatality risk of cyclists and of car occupants is much smaller (1.5 times higher); besides, there is much room for improvements in cyclist safety, for instance by increasing the use of helmets and conspicuity equipment. Traffic calming could also benefit cyclists, pedestrians and perhaps moped users.     

一种基于道路约束的变结构多模型跟踪算法

有效使用道路信息能显著提高地面运动目标跟踪性能。针对复杂道路网运动目标跟踪,给出了一种道路约束下的滤波和建模方法。首先描述了道路网的数学模型和道路约束条件下的过程噪声修正方法,根据道路约束最大后验概率估计准则给出了一种路段切换时状态和协方差修正公式;接着提出一种根据目标当前所处路段自适应滤波模型生成的变结构多模型(VSMM)方法,有效减小道路运动目标的模型动态误差,提高跟踪性能。仿真结果证明了该算法的优越性能。     

浅析沥青路面设计方法中应注意的问题

沥青路面的设计是一个较为复杂的系统工程,而且很难设计出经济合理的路面结构。本文主要讨论解决这一问题的措施,以及在现行的沥青路面设计、应用过程中的诸多问题。它有助于沥青路面设计和混凝土路面设计质量的提升,可供同行参考。     

道路有机硅密封胶的性能评价与技术要求

为了评价道路有机硅密封胶的性能,分析了国内外的各种技术标准,根据路用性能要求,提出了表干时间、固化时间、流平性、流值、弹性(复原)率以及低温拉伸这6个评价指标.分别对4种有机硅密封胶(2种进口材料和2种国产材料)进行试验,试验证实这些材料均为自流平材料,表干时间不超过90 min,固化时间为2～3周,弹性(复原)率均超过90％,90℃流值均为0 mm,-30℃下至少可通过100％拉伸量的3次循环.结果表明:有机硅密封胶是高弹性材料,具有开放交通快、施工方便等优点,且具有优越的高低温性能.另外还根据试验结果提出了相应的技术要求.