Optimal Strategies for Highway Pavement Management in Developing Countries

Highway pavement design in developing countries is usually based on standards borrowed from industrialized countries. However, it may not be economically feasible to use these high design standards in developing countries, because of significant differences in socioeconomic conditions. Using the World Bank's highway design and maintenance standards model (HDM-III), this paper investigates optimal pavement design and its relationship with the developmental stage of a country. Optimal pavement design can be defined as that which minimizes total transport costs to society, which comprise the sum of agency costs and road user costs. Basic data for the analysis were derived from Chinese conditions, and appropriate adjustments were made to model five classes of hypothetical countries in different developmental stages. It is shown that the optimal trade-off between initial expenditure on construction and subsequent maintenance depends on the developmental stage of an economy. The same high design standards that are suitable for industrialized countries may not be economically justified in developing countries. Developing countries should start with modest pavements and then spend more on maintenance afterwards, which is an overdue, neglected priority today.     

LQLY-1型沥青路面养护车

万达牌LQLY-1型沥青路面养护车,是我公司根据交通部“十五”攻关项目,以及结合公路养护新政策要求,在吸收国内外养护机械先进开发经验的基础上,自主研发制造的适合国情的新型快速机动的沥青路面养护设备。该设备集加热、保温、路面病害开挖处理、乳化沥青喷洒、修补碾压等多功能于一体,机动性好、维修快,作业时基本不影响交通;同时,还可提供作业所需的电力和压气动力,是适用于各等级路面维修养护和野外作业的综合一体设备。1主要技术参数基础车欧曼BJ1099VEPED(可选配)发电机组功率(kW)≥30加热板功率(kW)≥30破碎装置空压机排气量(m3…     

沥青路面未确知测度结构优选模型

高速公路投资额巨大,需要科学的路面结构选择方法。针对高速公路沥青路面结构方案评价过程中存在着许多不确定的知识和信息,应用未确知测度数学方法建立了高速公路沥青路面结构优选评价模型,该方法对评价空间实现了有序分割,通过建立多指标综合测度评价矩阵对不同方案进行识别排序。应用该模型对3种典型路面结构进行了综合评价。结果表明,采用该方法得到的评价结果能够较为客观地反映沥青路面结构的综合性能。     

城市道路沥青路面养护工艺、设备发展现状与趋势

沥青路面是城市道路的主要铺装形式之一,对其进行系统、快速的养护,能够有效地降低城市道路的运营成本,缓解城市交通的拥堵压力。文章总结了目前沥青路面养护工艺、设备现状,并针对城市道路养护的特点,介绍了沥青路面养护新技术、新设备的发展情况。     

Effect of Performance Model Accuracy on Optimal Pavement Design

In the first part of this paper, an analysis of the data collected during the American Association of State Highway Officials (AASHO) road test, based on probabilistic duration modeling techniques, is presented. Duration techniques enable the stochastic nature of pavement failure time to be evaluated as well as censored data to be incorporated in the statistical estimation of the model parameters. The second part of this paper presents the use of economic optimization principles for determining the optimal design of flexible pavements. We study the effect of deterioration model accuracy on optimal design and lifecycle costs by comparing three models. The first is a simple regression model developed by the AASHO, which forms the basis of design standards in use today. The second is a regression model that was developed with the same AASHO data set, but that includes a correction for data censoring. The third model is the probabilistic model developed in the first part of this paper. The results show that the AASHO model, when used as an input to lifecycle cost minimization, produces a pavement structural number that is lower than that produced by using the other two deterioration models. This results in shorter pavement lives and higher costs due to more frequent resurfacing. The savings in lifecycle cost accrued by using optimal structural number are shown to be quite significant, offering a sound basis for revising current design practices.     

公路路面养护对策的确定方法──以国道301线西段(哈尔滨—大庆)公路为例

本文根据公路所需要的道路服务水平、结构强度、路面损坏状况指数来综合确定公路路面的养护对策方法，可以提高养护质量，合理使用养护资金。这是由传统的、经验型养护管理方法向科学的养护管理方法的一个转变。     

微表处技术在预防性道路养护中的应用

在总结国内外微表处技术研究成果的基础上,介绍了微表处技术在我国的研究情况和应用情况:从混合料配合比设计、混合料性能影响因素、表面功能等方面对微表处技术目前的主要研究成果进行了概述,并对微表处技术在我国的推广应用前景进行了展望,提出了当前我国微表处技术推广应用的设想.     

Network‐Level Road Pavement Maintenance and Rehabilitation Scheduling for Optimal Performance Improvement and Budget Utilization

Abstract: This article discusses how to efficiently and completely solve a bi‐objective pavement maintenance and rehabilitation‐scheduling problem, which aims at optimizing two objectives of pavement condition improvement and budget utilization in a simultaneous manner. This problem may be addressed by the weighting method, constraint method, ranking method, and various metaheuristic methods. However, none of these methods can guarantee the complete Pareto‐optimal solution set, which would potentially lead to suboptimal decisions. In this article, a parametric method is suggested to solve the bi‐objective pavement maintenance and rehabilitation‐scheduling problem. The effectiveness and efficiency of the parametric method is investigated and demonstrated through a case study using the real‐world data set from the Dallas District's Pavement Management Information System. A performance comparison between the widely used weighting method and the parametric method clearly justifies the computational advantages of the parametric method.     

变水量空调系统的优化控制策略及其能耗分析

由于受气象条件等因素变化的影响,在实际运行过程中,空调系统的负荷大多小于其设计负荷.为达到节能和优化系统控制的目的,对三个实时优化控制策略进行系统能耗评估与分析:实时控制优化冷媒水供水温度、实时控制优化二级泵供水压力以及供水压力和供水温度串级优化控制.同常规的控制策略相比,这三个优化控制策略都能具有一定的节能效果,而且能够改善系统局部的控制特性.     

沥青路面微表处预防性养护技术的应用

介绍了微表处原材料设计、施工工艺,论述了质量控制方法。微表处技术是公路沥青路面有效的预防性养护措施,具有施工速度快,抗滑、抗磨耗性能好,可修复车辙,有很好的封水效果,能延长道路使用寿命等技术特性,具有十分广阔的市场应用前景。     

沥青砼路面最佳油石比的确定

分析了沥青混合料的构成以及矿料间隙率等对油石比的影响,确定了混合料最佳油石比的应用公式,通过实际工程数据检验了所用计算公式的正确性,并据此对混合料最佳油石比进行了估算.     

公路沥青混凝土路面预防性养护对策选择的研究

预养护对策选择是路面预防性养护的关键技术之一,决定着预养护措施选择的科学性和合理性。作为公路沥青混凝土路面预养护对策选择理论的进一步阐述,以上海市浦星公路为例,详细地分析和叙述预养护对策选择的方法和过程。分析结果可供具体工程应用参考。     

基于沥青路面功能性能的预防性养护时机指标

路面预防性养护是国内外近年来研究的热点,路面预防性养护对维持良好的路面性能具有重要的意义。预防性养护的成功与否及其效益与进行预防性养护的时机密切相关,然而对于预防性养护的时机目前国内外还没有很好的解决办法。文章从预防性养护的作用出发,结合我国公路事业发展的现状,提出了基于沥青路面功能性能的预防性养护指标体系:路面沥青老化指标、路面渗水系数、路面行车安全性指标、平整度和路面状况指数(PCI) ,以及获取这些指标需要进一步解决的关键问题。     

路面雾封层预养护技术使用效果的评价

沥青混凝土路面经过一段时间使用后,会出现路面抗滑性能、防水性能下降等问题,但其他路用性能尚处于良好状态。在这种情况下采用雾封层预养护措施是一种较好的养护方法。文章对某高速公路路面雾封层预养护段的抗滑性能和构造深度变化情况以及使用情况进行了跟踪调查,并对雾封层预养护技术使用效果进行了评价。     

高速公路沥青路面就地热再生养护设计的探讨

结合高速公路沥青路面就地热再生养护维修实际工程,从路面破损状况、结构承栽能力、旧路面材料性能等方面全面总结归纳就地热再生技术在养护维修中的设计要点,以供养护工作者参考。     

谈路面维护和修复管理系统的离散优化模型

随着公路建设和高速公路网在的迅速发展,路面维护和修复活动的管理已变得尤为重要。论文提出了涉及管理体制4个不同群体的离散优化模型,不同群体分别为:政府、高速公路代理人、承包商和普通用户。这4个最优决策模型的制定及二元决策变量的线性整数规划问题。目标函数和约束条件都是基于路面状况指数。数值实验对四川省的公路系统的数据进行分析,其表明了该模型的可行性和有效性。     

Optimizing Location and Capacity for Multiple Types of Locomotive Maintenance Shops

Thousands of locomotives run in the North America railroad network and each of them must receive periodic maintenance service; meanwhile, the locomotives may break down during shipment operations and demand repair. Maintenance shops are characterized by the types of locomotives they can handle and the level of service they can provide. This article formulates a mixed‐integer program model to optimize location and capacity of locomotive maintenance shops. The objective is to minimize the sum of the costs for building new (or shutting down existing) maintenance shops, the costs for capacity expansion (or reduction), and the costs for shipping broken locomotives to a suitable shop. A Lagrangian‐relaxation‐based heuristic algorithm is proposed to solve the shop location and capacity planning problem. The model and solution techniques are applied to a full‐scale real‐world case study, while the computational results show that the current maintenance shops are overly built and recommend that two maintenance shops should be closed and an amount of capacities should be reduced from the existing shops. A series of numerical sensitivity analyses are also conducted to draw managerial insights.     

轮胎压路机弯道行驶时轮胎对道路铺层滑移的分析

建立在圆周行驶状态下轮胎压路机行驶轨迹各参数的几何关系和计算公式,得出在轴距和转弯半径一定,且采用典型的轮胎布置形式时,轮胎对道路铺层的最大滑移率,分析驱动轮组的滑移率在轮胎宽度上的分布状态.行驶轨迹的几何关系公式和由此得出的最大滑移率数据表明,采用较小宽度的后驱动轮组可减小弯道行驶作业时轮胎对道路铺层的滑移,有利于提高道路施工质量.     

高等级沥青混凝土路面平整度的控制

1 平整度的重要性 路面平整度是评定沥青路面使用品质的重要指标,路面平整度的好坏,不但直接关系到行车的安全．舒适和车辆的行驶性能以及营运经济．而且路面的不平整,使行驶车辆的附加振动作用又反过来对路面施加冲击力,从而加剧路面的损坏。在道路工程中,平整度虽是众多道路技术指标的一项．但对于道路的使用情况来讲,平整度是影响道路使用功能较大的一项。在此．作者结合连徐高速公路CDE-21标的施工经验．就高等级沥青路面施工平整度控制作一些简要分析．以便在沥青路面的施工中能够引起重视。     

一般函数的计算机病毒模型最优控制

研究一类改进的一般函数的计算机病毒模型,并引入杀毒软件作为系统的控制变量,应用极小值原理,得到一个时变的最优控制策略。时变的控制策略不但能够使得购买杀毒软件及其更新的费用最小,而且能将被感染的计算机的数目降到最低。数值模拟显示:在控制的这段时间内,并不需要一直保持最大的效力。