山岭重丘区高等级公路改建工程路基施工

以安楚高速公路改建工程十三合同段为例,从技术准备、软土地基、防护及排水工程施工、路基挖方、路基填筑等5个方面重点介绍了山岭重丘区高等级公路改建工程的路基施工.     

基于FWD检测结果旧路地基脱空状况的模糊评定

总结了利用FWD检测旧路基层脱空的方法,分析其各自的优缺点。在此基础上优化评价方法,引入模糊思想,提出一种新的地基脱空评价方法—模糊评定法,详细介绍模糊评定模型的建立方法和过程,并结合G325国道粤境开平段路面大修改善工程,探讨利用FWD检测结果现场模糊评定旧混凝土路面地基的脱空状态。工程实践表明,该方法取得了很好的实用效果,有效地指导了路面大修施工。     

山区公路层间滑移破坏机理分析及对策研究

通过现场调查,初步分析了山区公路沥青路面基面层滑移的主要原因。应用有限元法,对基层和面层之间的剪应力进行计算分析,得出了基面层间剪应力变化的一般规律,认为层间最大剪应力主要取决于面层厚度和荷载条件。在前述计算分析的基础上,利用自行研制的DLG A路面材料剪切仪进行了大量的层间滑移室内模拟试验,考察了不同的层间处理措施、温度、基层类型等因素对层间抗剪能力的影响,提出了防止基面层滑移的技术措施。     

Consumer preferences and willingness to pay for advanced vehicle technology options and fuel types

The automotive industry is witnessing a revolution with the advent of advanced vehicular technologies, smart vehicle options, and fuel alternatives. However, there is very limited research on consumer preferences for such advanced vehicular technologies. The deployment and penetration of advanced vehicular technologies in the marketplace, and planning for possible market adoption scenarios, calls for the collection and analysis of consumer preference data related to these emerging technologies. This study aims to address this need, offering a detailed analysis of consumer preference for alternative fuel types and technology options using data collected in stated choice experiments conducted on a sample of consumers from six metropolitan cities in South Korea. The results indicate that there is considerable heterogeneity in consumer preferences for various smart technology options such as wireless internet, vehicle connectivity, and voice command features, but relatively less heterogeneity in the preference for smart vehicle applications such as real-time traveler information on parking and traffic conditions.     

Modeling duration choice in space–time multi-state supernetworks for individual activity-travel scheduling

Multi-state supernetworks have been advanced recently for modeling individual activity-travel scheduling decisions. The main advantage is that multi-dimensional choice facets are modeled simultaneously within an integral framework, supporting systematic assessments of a large spectrum of policies and emerging modalities. However, duration choice of activities and home-stay has not been incorporated in this formalism yet. This study models duration choice in the state-of-the-art multi-state supernetworks. An activity link with flexible duration is transformed into a time-expanded bipartite network; a home location is transformed into multiple time-expanded locations. Along with these extensions, multi-state supernetworks can also be coherently expanded in space–time. The derived properties are that any path through a space–time supernetwork still represents a consistent activity-travel pattern, duration choice are explicitly associated with activity timing, duration and chain, and home-based tours are generated endogenously. A forward recursive formulation is proposed to find the optimal patterns with the optimal worst-case run-time complexity. Consequently, the trade-off between travel and time allocation to activities and home-stay can be systematically captured.     

信号培训系统的虚实互动机制研究

从信号培训系统目前存在的问题出发,提出一种虚实互动的机制来构建信号培训系统的方法。研究结果表明,本方法可以针对目前信号培训的特点,建立能够适应不同线路环境,满足不同实物设备组成方式和实训实操要求的信号培训系统。     

景观道路的设计实践——广阳岛环岛路设计

广阳岛环岛路的主要功能是服务性景观路,跟环岛滨江公园一起,共同构筑广阳岛的滨江景观带。尝试引进了国外的宁静化设计,尽可能推行最生态的工程做法,努力创造人与自然相和谐的环境,并竭尽全力地将这些构想付诸实施。为了实现以上目标,道路、交通、排水、结构、桥梁和电照专业,在景观专业的组织下,共同展开了这条景观路的设计尝试。     

辽阳出口路现场热再生简析

重点介绍了辽阳出口路现场热再生沥青混合料的级配设计和施工工艺及施工过程中的质量控制要点。     

An optimal data-splitting algorithm for aircraft scheduling on a single runway to maximize throughput

In this research, we present a data-splitting algorithm to optimally solve the aircraft sequencing problem (ASP) on a single runway under both segregated and mixed-mode of operation. This problem is formulated as a 0–1 mixed-integer program (MIP), taking into account several realistic constraints, including safety separation standards, wide time-windows, and constrained position shifting, with the objective of maximizing the total throughput. Varied scenarios of large scale realistic instances of this problem, which is NP-hard in general, are computationally difficult to solve with the direct use of commercial solver as well as existing state-of-the-art dynamic programming method. The design of the algorithm is based on a recently introduced data-splitting algorithm which uses the divide-and-conquer paradigm, wherein the given set of flights is divided into several disjoint subsets, each of which is optimized using 0–1 MIP while ensuring the optimality of the entire set. Computational results show that the difficult instances can be solved in real-time and the solution is efficient in comparison to the commercial solver and dynamic programming, using both sequential, as well as parallel, implementation of this pleasingly parallel algorithm.     

Optimal bus fleet management strategy for emissions reduction

Transportation is a major cause for environmental degradation via exhaust emissions. For many transit-oriented metropolitan areas, bus trips often constitute a sizeable mode share. Managing the bus fleet, in particular updating buses to comply with the newer emissions standards, therefore, can have a substantial impact on transportation-induced air quality. This paper presents the approach of remaining life additional benefit–cost (RLABC) analysis for maximising the total net benefit by either early-retiring or retrofitting the current bus fleet within their lifespans. By referring to the net benefits for different bus types estimated by RLABC analysis, the most beneficial management scheme for the current bus fleet can be identified. Optimal bus fleet management (BFM) models based on the RLABC analysis for the operator and the government are developed. Then a government subsidy plan is produced to achieve win–win solutions, which will offer efficient and flexible management schemes. To illustrate the approach, the largest bus company in Hong Kong, which carries more than 23% of the total trips in Hong Kong, is taken as a case study example. Instead of adopting a fixed retirement plan, such as replacing buses at the age of 17 as is currently practised, the proposed method develops an optimal BFM scheme that progressively phases out buses or retrofits them. This study produces promising results to demonstrate the large benefit of this approach for optimal bus fleet management.