超薄罩面纤维提升性能技术研究

以广东省江罗高速公路预防养护工程为依托,对超薄罩面沥青混合料进行研究。为提升超薄罩面沥青混合料的路用性能,选定玻璃纤维粉材料作为核心添加剂使用,玻璃纤维粉具有重量轻、耐久性强、成本低等特性,且更为环保。将玻璃纤维粉分为0.02%、0.04%、0.06%、0.08%4档不同掺量作为外掺物加入沥青混合料中。根据高速公路路用性能要求,选取高温车辙试验、水稳定性试验、渗水试验、抗滑试验进行材料性能影响因素检测试验,研究结果显示：玻璃纤维粉最佳掺量为0.04%,当掺量为0.04%时动稳定度到达峰值,提升了约12.42%;冻融劈裂抗拉强度比和残留稳定度分别提高了约7.72%和7.08%;渗水性能与抗滑性能试验结果也均满足相关规范技术要求。试验结果表明,适量玻璃纤维粉的掺入可以有效改善超薄罩面沥青混合料的路用性能,并为预防养护工程提供相关的研究数据及参考建议。     

地铁车站出入口设施优化设置研究

闸机检票效率影响地铁车站的整体通行能力,且作用于乘客等待时间来影响社会效益。为此,从系统优化的角度出发,以稳态条件下单位时间总费用为目标函数,通过研究北京西直门地铁枢纽A口客流出入站的过程,分析影响闸机设置的因素,以客流需求、空间限制、成本投入、疏散要求等为约束条件,采用线性规划的方法,对闸机设置进行优化研究,分别确定普通闸机与加宽闸机的个数。根据优化结果,为科学组织高峰小时客流出入车站提供基础数据和重要参考,检验实设闸机的合理程度。     

Factors contributing to bicycle–motorised vehicle collisions: a systematic literature review

Bicycle–motorised vehicle (BMV) collisions account for the majority of the recorded bicyclists’ fatalities and serious injuries. This systematic review intends to examine the main factors contributing to BMV collisions. We performed a comprehensive literature review on Scopus, TRID, ProQuest, and Web of Science databases. Fifty-nine English-language peer-reviewed articles met the eligibility criteria and were included in the final analysis. The main factors contributing to BMV collisions identified were classified in accordance with a recently published conceptual framework for road safety. The majority of studies have identified factors related to road users’ behaviour (59.3%) and infrastructure characteristics (57.6%). A minority of studies identified variables related to exposure (40.7%) and vehicles (15.3%) as contributor factors to BMV collisions. A small but significant proportion of studies (20.3%) provided evidence that environmental factors may also play a role, although to a lesser extent, in determining BMV collisions. In addition to the three factors comprised in the applied conceptual framework for road safety, we identified environmental conditions as a category of factors contributing to BMV collisions.     

An Alert System for Beach Hazard Management in the Balearic Islands

A real-time beach hazard level associated with nearshore hydrodynamics is presented in this article. The suitability of the discussed alert system is illustrated via its application to fifteen beaches in the Balearic Islands (Western Mediterranean Sea) providing nearshore safety conditions for beach safety manager. The system provides daily forecasts of nearshore wave conditions using the deep water wave forecasts. The shallow water wave data (wave height, period, and direction) together with the morphology of the site (presence of bars, capes, beach type, etc.) are used to define a hazard level (low, medium, and high) associated with local conditions. The resulting hazard level is transmitted via SMS to lifeguards and local authorities for real-time beach management. The low computational cost of this system after the initial implementation and subsequent calibration results in a very suitable approach for beach management in order to mitigate risks related to local hydrodynamics.     

State-owned Spanish Port System oversizing: an analysis of maximum operational capacity

The State-owned Spanish Port System (SPS) includes 46 ports for general use that are managed by the 28 port authorities distributed along the 8000 km of Spanish coast. SPS has not grown at a rate comparable to that of international maritime transportation. In our paper, we start from the hypothesis of a port system that appears to be oversized, subsidized, with regard to container traffic. Quantifying the maximum operational capacity of the different container terminals along the Spanish coast and their mooring capacities will provide the available dimensions for this type of traffic. In a second step, we will analyse whether SPS are sufficient (according to the perspective of international standards) to meet Spain’s needs, which is related to Spain’s strategic geographic location and its need to move containerized cargo for the domestic market. The paper concludes SPS has an oversized that limits competitiveness, which is indicated by the average transshipment ratio of approximately 50% and an average unweighted idle ratio of port facilities designed for container traffic of over 60% in the eight main ports.