考虑层间接触状态的水泥砼路面有限元分析

文章以广西柳南高速公路和桂柳高速公路的典型路面结构为研究对象,建立三维有限元模型,进行水泥混凝土路面结构模拟计算,分析水泥混凝土路面板与基层的层间接触状态对路面结构的挠度及荷载应力的影响。     

GIS-based highway design review system to improve constructability of design

This paper presents a Geographic Information Systems (GIS) as a tool which can help highway engineers review a completed highway design to improve its constructability. The GIS can link different data sets together using geographical location as the common key between the data sets to perform various spatial operations. In this paper, the GIS is used to integrate various highway design data using a common milepost referencing system. The GIS allows the integration of the highway design information by establishing common spatial relationships between various highway design features and their geographical locations. The GIS can provide a comprehensive platform upon which all aspects of the highway project review process can be built. This paper also addresses the interface of GIS with the existing highway project data bases and computer-aided design files. The proposed GIS-based highway design review system can improve the constructability of the highway design at an early design review stage.     

公路隧道工程的环境问题及其对策研究

环保是21世纪最大的课题,而在公路隧道建设中,仍存在很大的问题,本文以公路隧道洞口设计为重点,提出采用绿色洞口、棚洞这两种新型环保的洞门设计,介绍了其施工的工序,最后就隧道洞门设计现阶段存在的问题展开讨论,并提出应对措施。     

Applicability of highway alignment optimization models

This paper presents an intelligent optimization tool that assists planners and designers in finding preferable highway alignments, connecting specified endpoints or zones. It integrates genetic algorithms with a geographic information system (GIS) for optimizing highway alignments and processes massive amounts of relevant data associated with highway design and alternative evaluation. To show the applicability of the proposed model to a real-world problem, two actual highway projects in the state of Maryland have been analyzed using the model. An extensive analysis of sensitivity to key model parameters is also conducted to describe the model capabilities. The analysis results show that the model can effectively optimize highway alignments in an area combining complex terrain and various types of natural and cultural land-use patterns, and provide detailed information of optimized alignments as a model output. It is also found that the alignments optimized by the model are quite similar to those obtained through conventional manual methods by a state agency, but the model can greatly reduce the time required for highway planning and design as well as produce lower cost solutions. Finally, the results confirm that all dominating and alignment-sensitive costs should be simultaneously evaluated in the alignment optimization process because many trade-off opportunities exist among those costs. The proposed model can greatly contribute to the productivity of highway planners as well as to the quality of the resulting infrastructure.     

Introducing change to transportation and energy systems: the case of alcohol fuels

This paper describes the application of optimization techniques to the problems of garage location and bus routing. The technique employed involves the decomposition of a garage location and bus routing model into two submodels. Solutions for the garage location and bus routing submodels are combined iteratively to find an optimal solution for the overall optimization model. Significant cost savings realizable for the Transit Authority of River City (Louisville, Kentucky) were calculated by implementing the results.     

Evaluating speed consistency between successive elements of a two-lane rural highway

The V₈₅ speed reflects the 85th percentile speed of vehicles in a traffic stream passing a given element on the highway section. The large amount of speed differential in V₈₅ between the two successive elements along a highway reflects lack of speed consistency in the highway section. This lack of speed consistency can result in increased crash risk. Recent research points to several problems associated with the conventional method of measuring ΔV₈₅ between successive highway elements: (1) failure to reflect individual vehicle speed profiles; and (2) failure to account for inter-dependence in individual vehicle speeds between successive elements. These problems have serious implications for justifying safety treatment when conventional ΔV₈₅ measure is applied. A number of researchers have suggested that the estimated speed differential based on individual vehicle speed profiles in successive elements is significantly higher than that obtained using the conventional approach. In this paper, we assess the safety implications of using the conventional ΔV₈₅ and introduce a hierarchical model for considering individual vehicles speed consistency. These findings lead to important implications for introducing engineering treatments to improve safety along in two-lane rural highways based on the criteria of speed consistency.     

旧水泥混凝土路面评价模型

文章对国道322线全州-桂林段的路面破损状况、结构承载力、行驶质量等方面进行调查,建立了旧水泥混凝土路面评价模型,为科学合理地制定该线路路面改造技术方案提供依据。     

A note on highway capacity

This note shows that on a homogeneous, uninterrupted flow highway there can be three kinds of capacity for any location: one for acceleration flow, one for deceleration flow and another for stationary flow. It is the stationary (equilibrium) flow capacity that one should adopt as the ideal capacity of a roadway, as defined by the highway capacity manual.     

PPP模式下高速公路项目施工期环境保护与水土保持管理探讨

PPP工程总承包是国家现阶段正在推行的建设项目组织模式,以专业投资公司联合专业施工单位及设计院为主进行PPP工程总承包是新兴的一种探索模式。在国内环水保形势日益严峻的情况下,如何做好PPP模式下高速公路项目环水保管理工作成为新的挑战。通过张扁高速公路PPP模式的应用,从公路工程建设过程中产生环、水保问题的原因与危害着手,分别从建设单位、监理单位、施工方简单阐述了各自的环、水保管理责任以及具体的控制措施;建设单位作为环、水保工作的总组织者、总协调者的作用不容忽视,在建设单位统一布局与领导下,通过有效管理可将环、水保问题控制在可控范围,使我国的高速公路建设向着生态公路的方向发展。     

新农村建设背景下加快广西农村公路发展对策探讨

文章基于农村公路建设在社会主义新农村建设中的重要性,分析了广西农村公路建设发展中存在的问题,提出了加快广西农村公路发展的相关对策,以期不断提高广西农村公路建设和管理的水平.     

A Fuzzy Multi-Criteria Model applied to the management of the environmental restoration of paved highways

This paper presents a procedure for ranking environmentally valid highway restoration by priority, using a Fuzzy Multi-Criteria Model that supports decisions on which road segments require these works and services. This is a matter of much concern for the Brazilian Government, due to rising awareness of soil degradation and the depletion of plant cover, as accident rates and transport costs rise steadily. The criteria used are: risk of accidents, economic and strategic importance, environmental degradation and the risk of erosion and landslides along the highway. In order to apply the proposed model, an example compares two highway segments, conducting sensitivity analyses through weighting the sub-criteria and criteria.     

Integrated approach to determine highway flooding and critical points of drainage

Among the natural hazards that threaten transportation infrastructure, flooding represents a major hazard to highways as it challenges their design, operation, efficiency and safety. In extreme cases, it may lead to massive obstruction of traffic and direct damages to the road structures themselves and indirect damages to the economic activity and development of the region. To enable the prevention of such consequences, and the proposition of adaptive measures for existing infrastructure, this paper presents an integrated framework to identify the most vulnerable points to flooding along a highway. This is done through the combination of remote sensing information (e.g. LiDAR based Digital Elevation Model, satellite imagery), a high-quality dataset, and a quasi-2D hydrodynamic model. The forcing condition is defined using a hyetograph associated to a storm with duration of 1 day and return period of 100 years. The selected highway is located in the Mexican state of Tabasco, where extreme precipitation events and floods are frequent. Results demonstrate the ability of the methodology to identify critical water levels along the road (h > 1.50 m) at those locations where flooding has been experienced, as well as points of inspection for the highway drainage. These locations were visited in the field and maintenance problems were detected that do increase its level of exposure. We show that this framework is useful for the generation of a flood management strategy to the analyzed highway, which includes an optimum location of adaptive measures to an anticipated more intense future climate.     

The relationship among highway geometrics,traffic-related elements and motor-vehicle accident frequencies

This research provides a demonstration of a statistical model of accident frequency that can eventually be used as part of a proactive program to allocate safety-related highway improvement funds. Negative binomial regressions of annual accident frequency on sections of principal arterials in Washington State were estimated using data from two years (1992 and 1993). In all, 31306 observations were used in model estimation (annual accident frequencies on specific sections of highway). Our estimation results isolated the effects of various highway geometric and traffic characteristics on annual accident frequency. Subsequent elasticity computations identified the relative importance of the variables included in our specifications. The findings show that the negative binomial regression used in this paper is a powerful predictive tool and one that should be increasingly applied in future accident frequency studies.     

理正勘察软件在山区公路中的应用分析

文章基于理正勘察软件在公路勘察中的应用特点,分析了理正勘察软件在山区公路绘制地质纵断面图中存在的问题,探讨了解决问题的途径,并提出运用屏占比确定公路工程地质纵断面图的最佳比例,同时介绍了理正勘察软件应用过程中的相关经验。     

山区水电工程场内公路路线设计探讨

文章针对山区水电站场内公路路线节点多、平面交叉多、立体分布广泛、上下线施工干扰大、布线方案困难等特点,对山区水电站场内公路路线布置与选线的原则、路线平纵设计方法、路线设计对构造物的影响等进行了分析探讨,为山区水电工程场内公路路线设计提供参考。     

Modeling intermodal equilibrium for bimodal transportation system design problems in a linear monocentric city

This paper investigates the intermodal equilibrium, road toll pricing, and bus system design issues in a congested highway corridor with two alternative modes - auto and bus - which share the same roadway along this corridor. On the basis of an in-depth analysis of the demand and supply sides of the bimodal transportation system, the mode choice equilibrium of travelers along the continuum corridor is first presented and formulated as an equivalent variational inequality problem. The solution properties of the bimodal continuum equilibrium formulation are analytically explored. Two models, which account for different infrastructure/system regulatory regimes (public and private), are then proposed. In the public regulatory model, the road toll location and charge level are simultaneously optimized together with the bus service fare and frequency. In the private regulatory model, the fare and frequency of bus services, which are operated by a profit-driven private operator, are optimized for exogenously given toll pricing schemes. Finally, an illustrative example is given to demonstrate the application of the proposed models. Sensitivity analysis of residential/household distribution along the corridor is carried out together with a comparison of four different toll pricing schemes (no toll, first best, distance based, and location based). Insightful findings are reported on the interrelationships among modal competition, market regulatory regimes, toll pricing schemes, and urban configurations as well as their implications in practice.     

公路灾害应急管理方案研究

文章阐述了公路灾害对道路网的影响,并针对宁波市江北区公路桥面结冰、下穿道积水及水毁灾害的特点,分析了公路灾害应急管理所存在的关键问题,提出了相应的应急管理方案。     

营松路互通立交与服务区合并设置设计

在吉林省营松高速公路项目中,燕平互通立交与靖宇服务区合并设置,设计中通过方案对比,选定了适合本项目特点的互通立交型式、服务区位置及结合方式,充分发挥互通立交的功能,提高服务区水平,达到合并后的和谐统一。     

玉林市公路交通运输对区域经济发展的影响分析

公路交通运输与区域经济发展密不可分,公路交通的发展程度必然会对区域经济发展产生极大的影响。文章以玉林市为例,运用弹性系数法,通过详细的数据对比和计算,系统地分析了公路交通运输对玉林市经济活动区位、区域产业结构及经济发展水平的影响,表明公路交通运输在玉林市区域经济发展的过程中占据了重要的地位。     

Multi-objective highway alignment optimization incorporating preference information

This paper presents a GIS-based multi-objective optimization model, particularly designed to aid highway engineers and planners in proposing competitive highway alignment alternatives when building a new highway or expanding an existing highway. The proposed model can effectively examine tradeoffs among various objectives that represent possibly conflicting interests of different stakeholders. A Hybrid Multi-Objective Genetic Algorithm, which utilizes designers’ knowledge about the preference of decision makers, is developed to search for a set of Pareto-optimal solutions with an acceptable level of diversity. Two case studies demonstrate the capability of the proposed approach in providing multiple trade-off solutions. The results indicate that the incorporation of preference information, even if preliminary in nature, has great potential to save computation time and improve the quality of the obtained Pareto-optimal set.