Raman detection of hydrohalite formation: Avoiding accidents on icy roads by deicing where salt will not work

The common substance Hydrohalite has a role to play in as diverse areas as Geology, Earth Climatology, Universe Cosmology, and Cryobiology. In this review, the occurrences under very different occasions are described. These relations are not commonly appreciated. During the work, we realized that there is yet an aspect that has been overlooked. Hydrohalite formed sometimes on icy roads resists common salt deicing procedures. Also, hydrohalite can be detected by rather simple Raman spectroscopy instrumentation. It means that it is possible to avoid accidents on icy roads in the following way: Common salt deicing trucks may be equipped with “artificial intelligence” based on a duel deicing system that switches between normal NaCl deicing and non-NaCl deicing based on Raman spectroscopy. The advantages are first of all less traffic accidents and lower environmental impact and corrosion from NaCl, but disadvantages are increased costs of investments and consumption of non-NaCl deicing agents.     

旧路拓宽全过程三维有限元分析

旧路拓宽是西部山区高等级公路建设中的重要课题。运用岩土工程专业软件包P laxis 3D Tunnel,对旧路拓宽进行了全过程的三维弹塑性有限元数值模拟,包括新路基的填筑,路面各结构层的铺筑及轮载最不利位置的施加等,重点分析了新旧路基不均匀沉降变形及应力分布的规律,比较了拓宽方式、新老路基土模量差异对路面变形和使用寿命的影响,并就实际施工提出了一些建议。     

Suspension settings for optimal ride comfort of off-road vehicles travelling on roads with different roughness and speeds

This paper reports on an investigation to determine the spring and damper settings that will ensure optimal ride comfort of an off-road vehicle, on different road profiles and at different speeds. These settings are required for the design of a four stage semi-active hydro-pneumatic spring damper suspension system (4S₄). Spring and damper settings in the 4S₄ can be set either to the ride mode or the handling mode and therefore a compromise ride-handling suspension is avoided. The extent to which the ride comfort optimal suspension settings vary for roads of different roughness and varying speeds and the levels of ride comfort that can be achieved, are addressed. The issues of the best objective function to be used when optimising and if a single road profile and speed can be used as representative conditions for ride comfort optimisation of semi-active suspensions, are dealt with. Optimisation is performed with the Dynamic-Q algorithm on a Land Rover Defender 110 modelled in MSC.ADAMS software for speeds ranging from 10 to 50 km/h. It is found that optimising for a combined driver plus rear passenger seat weighted root mean square vertical acceleration rather than using driver or passenger values only, returns the best results. Results indicate that optimisation of suspension settings using one road and speed will improve ride comfort on the same road at different speeds. These settings will also improve ride comfort for other roads at the optimisation speed and other speeds, although not as much as when optimisation has been done for the particular road. For improved ride comfort damping generally has to be lower than the standard (compromised) setting, the rear spring as soft as possible and the front spring ranging from as soft as possible to stiffer depending on road and speed conditions. Ride comfort is most sensitive to a change in rear spring stiffness.     

弹性聚氨酯型混凝土道路嵌缝胶研制与应用

采用聚氧化丙烯三醇,甲苯二异氰酸酯等为原料成功研制出弹性聚氨酯型混凝土道路嵌封胶。该嵌缝材料具有伸长率大、弹性高、与混凝土粘接力强、色彩可调、表干时间适宜,并可在缝内潮湿情况下施工等技术特点。该材料主要性能指标优于国内同类产品,目前已在广东省内数条混凝土道路上获得了推广应用并取得良好的技术效果。     

Converting the UK calculation of road traffic noise (CORTN) to a model capable of calculating LAeq,1h for the Tehran’s roads

This paper describes the methodology through which the UK calculation of road traffic noise (CORTN) has been converted to the algorithms that are able to calculate hourly A-weighted equivalent sound pressure level (L_Aeq,1h) for the Tehran’s roads. The methodology adopts two different approaches to model calibration and performance test through the holdout validation method on the basis of the database including 52 samples taken from 52 sampling stations located alongside 5 roads of Tehran at distances less than 4 m from the nearside carriageway edge. As to the CORTN manual the distances less than 4 m are considered to be equal to 4 m. In the first approach the model is calibrated through carrying out nonlinear regression parameter estimation using 50% of samples to replace the basic noise level parameters with the new ones that are presumably able to satisfy the objective of the study with an acceptable fitness of the model. In the second approach the model calibration is carried out on the basis of 30 measurements taken from 2 roads. In the next step the other subsets of samples are introduced into the calibrated equations to conduct the performance test. Non parametric goodness of fit tests, i.e. two related samples Wilcoxon and two independent samples Kolmogorov-Smirnov, respectively conducted for the calibration and the performance test steps; indicate satisfactory results for both approaches.     

基于权的最小平方法的山区道路交通安全度模糊综合评价

针对山区道路交通特点,综合考虑影响山区道路交通安全度的人、车、路、环境等主要因素,运用层析分析法构建道路交通安全度评价指标体系,基于权的最小平方法建立模糊综合评价模型,并利用加权平均原则对其进行综合评价.以云南省罗富路"者桑"段为例,结果表明该模型可以有效的反映道路的安全状况,且权的最小平方法可以实现道路交通安全度主要影响因素权重系数的精确分配,合理反映各评价指标的重要性,为提高道路的交通安全性奠定基础.     

Identification of superfluous roads in terms of sustainable military land carrying capacity and environment

A great challenge the US military land managers are often faced with is how to optimize road networks in order to maintain roads (including all roads, trails, and paths) for the purpose of military training and reducing negative impacts on environment. In this study, a methodology was developed to identify superfluous roads for being closed in terms of both sustainable military land carrying capacity and environment for Fort Riley. In this method, Geographic Information Systems (GIS), remote sensing, and landscape analysis technologies were combined to derive various spatial data layers of factors that had significant impacts on both military training and environment. The factors included maintenance cost of roads, road access area, military training intensity, soil erosion, water quality, landscape fragmentation, and noise production. The factors were quantified and normalized. A spatial multicriteria decision was then developed to obtain the weights of the factors, combine the data layers, and derive a priority map of all the roads for being closed. This map summarized the negative and positive impacts of the factors on environment and military land carrying capacity and can provide the US military land managers with useful guidelines and tools for determining superfluous roads in terms of both sustainable military training and environment. It is expected this effort can provide a method to quickly ascertain which roads are most cost-effective for being closed without hindering the mission and at the same time with benefits for environmental protection and thus provide the land managers with a comprehensive analysis and assessment of alternatives at their disposal.     

光谱特征分析的城市道路提取

道路是城市中典型的人造地物。利用高分辨率影像进行城市道路提取,对城市规划、交通发展具有重要意义。由于地物光谱的混淆性和异质性,利用传统基于光谱的分类方法很难将道路与其他城市地物区分开。针对这一问题,提出了一种利用道路边缘结构信息进行分类的方法,边缘作为光谱衍生信息对线性地物(如,道路等)识别具有明显的意义。首先,根据全色光谱波段纹理信息,利用改进的自适应Mean Shift算法进行边缘检测,最大限度减少噪声与伪边缘;然后,对边缘图像中的线段进行编组,利用统计模型依次对边缘线段求取统计特征,并将该统计特征与多光谱特征结合作为总分类特征;最后,利用监督学习方法对城市道路样本进行学习并对整个实验区域进行分类。结果表明将光谱信息与边缘统计特征融合对道路的识别精度为93%,相比传统方法78%的精度有显著的提高,因此,该方法是一种有效、可行的高分辨率遥感图像城市道路提取方法。     

青藏铁路路基加宽的变形特征研究

通过青藏铁路清水河冻土站场路基试验段冻土路堤、地基的沉降变形、水平位移、地温及路堤温度等进行较全面的试验和监测,分析了路基加宽对冻土路基温度场及变形产生的影响。     

Influence of expanding ring roads on traffic noise in Beijing City

The road network in Beijing is expanding in the form of loop-lines. Following the 2nd and 3rd ring roads, the 4th has been completed and come into operation in 2002. Traffic noise surveying and analysis was performed along four main roads in the Beijing urban area—the 2nd, 3rd and 4th ring roads circling the central downtown area and Chang-An Avenue, a major east-west corridor through the heart of the city. Measured noise data along the 2nd, 3rd and Chang-An Avenue were compared with the data surveyed before the completion of the 4th ring road for determining influence of expanding ring roads on traffic noise pattern in Beijing City. The results indicate that these main roads remain overloaded by traffic flow during daytime, and noise levels due to road traffic along these roads exceeds relavent environmental standards by 5 dBA. Reduced traffic noise level was observed along the northern half of the 2nd and 3rd ring roads, and along the central section of Chang-An Avenue. Increased traffic noise level was observed along the southern half of the 2nd and 3rd ring roads, and along the non-central section of Chang-An Avenue. Expanding ring roads mitigate heavy traffic flow in the central part of Beijing City, but spread high traffic noise outwards at the same time.