论旧路改建的设计与施工

结合多年来对青海公路地区旧路改建的设计、施工经验介绍旧路改建时平、纵面设计中注意的问题,同时对旧路面补强的设计和施工的防治要点进行了分析。     

旧水泥混凝土路面沥青加铺层温度应力有限元分析

文章基于路面温度场理论,采用ANSYS程序建立旧水泥混凝土路面沥青加铺层结构温度应力有限元模型,分析了降温幅度、加铺层厚度和土工布夹层材料模量及典型防止反射裂缝措施对旧路接缝处沥青加铺层底温度应力的影响,为选择合理材料和设计参数进行沥青加铺层设计提供参考。     

无纺土工布在路面裂缝防治中的应用

介绍无纺土工布在旧沥青路面和旧水泥混凝土路面上加铺沥青面层中.防治反射裂缝的作用机理和施工技术.     

济枣西线(小坞-休城段)新材料应用试验研究

阐述了在旧水泥混凝土路面上加铺纤维沥青混凝土路面,铺设土工布,防治沥青路面反射裂缝的关键技术.     

旧水泥砼路面加铺级配碎石补强层施工工艺探讨

如何有效防治旧水泥混凝土路面上加铺沥青面层产生反射裂缝,是路面修复工程中所面临的一个较普遍问题。文章以国道324线田阳段利用级配碎石作为补强层成功处理该问题为实例,探索了旧水泥砼路面加铺级配碎石补强层的设计与施工方法。     

浅谈沥青混凝土面层施工技术

阐述旧水泥混凝土路上加铺沥青混凝土罩面层进行改造的施工经验;简要介绍旧混凝土路面的补强措施.     

旧水泥混凝土路面沥青加铺层结构研究

通过对旧路的使用及评定情况进行总结,对旧水泥混凝土路面沥青加铺层结构进行了研究和探讨,同时结合某省道公路的现状,提出沥青加铺层不同的设计方案,并分别进行分析和探讨,以期对旧水泥混凝土路面性能的改善起到促进作用。     

浅谈旧路拓宽路基设计

通过工程实例,探讨了旧路拓宽改造时路基的设计方法,分析了旧路拓宽后出现差异沉降的原因及防治对策。     

旧路改建项目中路基路面勘察设计对策研究

为更好地满足我国经济持续发展的现实需求,需要在交通运输领域进行完善,不断优化旧路改建项目实施效果。文章介绍了旧路改建项目的勘察内容,从新旧路基的衔接处理、填方边坡、防护工程、路面结构、排水功能等方面,提出了旧路路基路面的改造设计方法和对策。     

永福至鹿寨公路潮水至波寨段路线方案比选分析

文章结合广西公路旧路改建工作实际,介绍了存在复杂交叉关系的旧路改建项目的基本特点及解决方法,并以永福至鹿寨公路潮水至波寨段工程为例,提出了不同的路线设计方案,对比分析各方案对路线选线的影响,为今后广西区域旧路改建项目的选线工作提供参考。     

现行沥青路面设计规范存在问题探讨

文章从设计标准、交通荷载、材料参数及设计方法四方面阐述我国现行规范中沥青路面结构设计的原理及存在的问题,并提出了需进一步完善的建议。     

Transportation infrastructure improvement and real estate value: impact of level crossing removal project on housing prices

This paper studies the impact of removing the level crossing, which constitutes traffic hazard to the society, on house prices by conducting a quasi-natural experiment using the Level Crossing Removal Project (LXRP) implemented by the Victoria state government in Australia since 2015. Using a difference-in-differences method, we analyzed the changes in housing prices due to the improvement of transportation infrastructure, gauging the LXRP’s impact on house and unit submarkets separately. We found that the prices for house and unit markets increased significantly after the removal of level crossings, with the value uplift decreasing with distance from the removal site. This paper contributes to the existing literature by adding an empirical study related to the enhancement of infrastructure aiming to improve the traffic safety in the urban context. Unlike previous studies, this study examines the effect of improvement projects for existing infrastructure and provides relevant implications to improve the efficiency of investing public resources in infrastructure improvement.

     

基于VISSIM的城市非互通式立体交叉口交通拥堵改善研究

文章分析了城市非互通式立体交叉口存在的问题及其成因,并以甘肃省兰州市北滨河路和城关黄河大桥立交为实例,提出了四种改善方案,同时运用VIS-SIM仿真软件对所提出的改善方案进行模拟和对比,得出最优的改善方案,为非互通式立交交通改善提供理论依据。     

An artificial neural network approach for evaluating transportation network improvements

As demand increases over time, new links or improvements in existing links may be considered for increasing a network's capacity. The selection and timing of improvement projects is an especially challenging problem when the benefits or costs of those projects are interdependent. Most existing models neglect the interdependence of projects and their impacts during intermediate periods of a planning horizon, thus failing to identify the optimal improvement program. A multiperiod network design model is proposed to select the best combination of improvement projects and schedules. This model requires the evaluation of numerous network improvement alternatives in several time periods. To facilitate efficient solution methods for the network design model, an artificial neural network approach is proposed for estimating total travel times corresponding to various project selection and scheduling decisions. Efficient procedures for preparing an appropriate training data set and an artificial neural network for this application are discussed. The Calvert County highway system in southern Maryland is used to illustrate these procedures and the resulting performance.     

Methodology to determine service delivery levels for public transportation

When designing transit services, the Level-of-Service concept has been widely used by transport planners and service providers to assess the service quality of an existing transit system. In addition to the service quality assessment, service providers also need to estimate the service levels that will satisfy a maximum number of users and potential users, across all socio-economic groups, so as to maximize patronage. This paper demonstrates a method using the concept of ‘user satisfaction levels’ and their ‘zone of tolerance’, along with total utility and marginal utility for service providers, to provide a range of service delivery levels for individual transit service attributes in the city of Kolkata. This range of service levels provides a guideline for service providers within which they can consider making an improvement in service level. However, the final decision on service improvement is an outcome of both financial and infrastructural feasibility.     

A State-of-the-Art Review of Car-Following Models with Particular Considerations of Heavy Vehicles

Abstract

Car-following (CF) models are fundamental in the replication of traffic flow and thus they have received considerable attention. This attention needs to be reflected upon at particular points in time. CF models are in a continuous state of improvement due to their significant role in traffic micro-simulations, intelligent transportation systems and safety engineering models. This paper presents a review of existing CF models. It classifies them into classic and artificial intelligence models. It discusses the capability of the models and potential limitations that need to be considered in their improvement. This paper also reviews the studies investigating the impacts of heavy vehicles in traffic stream and on CF behaviour. The findings of the study provide promising directions for future research and suggest revisiting the existing models to accommodate different behaviours of drivers in heterogeneous traffic, in particular, heavy vehicles in traffic.     

南宁外环公路膨胀土堑坡土质特性及防护措施

文章以南宁外环高速公路的膨胀土(岩)路堑边坡为对象,基于边坡破坏的原因及特点,开展了膨胀土(岩)边坡的土性试验,并针对边坡的不同特点,提出了坡脚矮挡土墙+浆砌片石骨架+铺两布一膜、土工格栅柔性支护、土工格室柔性支护等多种不同土工材料的边坡支护处治方案。工程实施表明所采取的方案措施能经济有效地解决南宁外环高速公路的膨胀土路堑边坡问题。     

柳南路旧路面沥青砼加铺层结构设计方法

结合柳南高速公路旧水泥砼路面改造工程,在综合基础资料调查结果及现有实际经验的基础上,依据加铺层结构设计原则,提出了旧水泥砼路面上沥青加铺层的结构方案,以及保证沥青加铺层使用性能的技术要求与措施。     

路企直通运输利弊分析及改进对策

文章针对铁路货物运输现状,阐述了路企直通运输带来的好处,同时分析了路企直通运输存在的问题,并提出了相应的改进建议。     

白改黑工程中反射裂缝防治措施研究

旧水泥混凝土路面白改黑工程中反射裂缝防治措施对延长路面使用寿命意义重大。文章通过间接弯拉试验、间接剪切试验、轮碾试验,分别测试采用无夹层、封层、封层＋防水卷材、封层＋土工布、封层＋玻纤格栅、封层＋聚酯纤维布等不同防裂夹层材料的防裂措施的层间间接弯拉强度、间接抗剪强度及其轮碾疲劳寿命,并结合实体工程对防水卷材的防裂效果进行跟踪调查,进一步说明其反射裂缝防治措施的可行性。