土工合成材料加筋法处治软弱地基的工程应用探析

文章介绍了土工合成材料加筋法处治软弱地基的基本原理、适用范围、施工要点及其垫层设计等内容,得出在软弱地基浅层处理中应用好土工合成材料加筋法,能够保障软基处治施工质量,提高路堤使用耐久性及安全度,节省投资等结论。     

土工合成材料在常发性浸水公路路堤养护中的应用

常发性浸水公路路堤养护是一项重要的工作,土工合成材料作为一种新型的材料,具有优良的物理和化学性质,能够有效提高路堤的稳定性和抗浸水性能。基于此,以土工合成材料中的水性环氧树脂乳化沥青材料为例,对其在某高速公路常发性浸水段路堤养护中的实际应用进行分析,包括施工准备、施工要点等,并对应用效果进行评价,以期为同类工程提供参考。     

土工合成材料在公路地下排水中的应用研究

文章对土工合成材料在公路地下排水中的应用进行总结分析,重点研究了土工合成材料应用技术中的选材依据及各种公路地下排水设施的设计方法、施工工艺和质量评价标准。     

土工合成材料综述

土工合成材料作为一种新型的岩土工程材料,近年来被广泛应用于交通、水利、建筑等工程领域。文章从土工合成材料的发展历史、分类、功能及应用等几方面出发,对这种新型材料给予较系统的阐述,并对土工合成材料在我国的进一步应用作了展望。     

土工合成材料在沥青路面施工中的应用

土工合成材料种类非常多,可以根据工程的不同要求选择不同的类型进行应用,能有效提升路面基础整体性能。文章主要探讨了沥青路面施工中土工合成材料的应用,分别从土工合成材料的功能特点、沥青混凝土的主要问题及形成原因,结合土工合成料的实际应用等方面进行分析。     

水泥搅拌桩复合地基体系在软土地基处理中的应用

文章基于土工格栅、土工格室、深层水泥搅拌桩的作用机理,以广西玉林至铁山港高速公路软土地基施工为例,介绍了土工合成材料与水泥搅拌桩组成的复合体系的设计方案,提出了该复合体系处理软土地基的施工工艺与质量检验方法。     

土工格室在阿李公路中的应用

土工合成材料在公路中的应用日趋广泛。结合我省阿李公路工程首次采用土工格室材料进行欠稳定边坡防护处理,对施工中的有关技术性问题进行讨论,总结土工格室的施工经验,避免和减少工程质量问题。     

土工合成材料在国外路基加筋中的应用研究

文章总结回顾国外土工合成材料加筋路基力学机理、试验研究及设计方法研究现状,通过对现有路基加筋设计方法进行比较,指出现有土工合成材料加筋设计方法的不足,并就今后需进一步研究的领域提出建议。     

贵港至合浦高速公路花岗岩残积土软基换填适用性研究

文章结合广西贵港至合浦高速公路工程软基换填量大,砂砾、碎石、片石等料源紧张,沿途弃土场征地困难等特点,从物理分析、化学分析两个角度对公路沿线花岗岩残积土展开研究,探究其作为软基换填材料的可能性。实践证明,采用片石+碎石垫层+强度较高、压实性能较好的砂性土、角砾土对项目区软基进行处治,可以达到规范要求,从而也证实了花岗岩残积土可以作为贵港至合浦高速公路软基换填材料。     

路基沉降的原因及处理措施

为提高道路工程的施工质量,对路基沉降的发生机理及原因进行分析,主要包括地理因素、水文因素、材料因素、技术因素等;针对路基沉降的原因提出具体的处理措施。对路基本体进行压实处理,并采用换填法、强夯法、使用土工合成材料、采用水泥搅拌桩技术等提高路基的压缩模量,可达到减少路基沉降现象,提高道路工程质量的目的。     

Crowdsourced data for bicycling research and practice

ABSTRACT

Cities are promoting bicycling for transportation as an antidote to increased traffic congestion, obesity and related health issues, and air pollution. However, both research and practice have been stalled by lack of data on bicycling volumes, safety, infrastructure, and public attitudes. New technologies such as GPS-enabled smartphones, crowdsourcing tools, and social media are changing the potential sources for bicycling data. However, many of the developments are coming from data science and it can be difficult evaluate the strengths and limitations of crowdsourced data. In this narrative review we provide an overview and critique of crowdsourced data that are being used to fill gaps and advance bicycling behaviour and safety knowledge. We assess crowdsourced data used to map ridership (fitness, bike share, and GPS/accelerometer data), assess safety (web-map tools), map infrastructure (OpenStreetMap), and track attitudes (social media). For each category of data, we discuss the challenges and opportunities they offer for researchers and practitioners. Fitness app data can be used to model spatial variation in bicycling ridership volumes, and GPS/accelerometer data offer new potential to characterise route choice and origin-destination of bicycling trips; however, working with these data requires a high level of training in data science. New sources of safety and near miss data can be used to address underreporting and increase predictive capacity but require grassroots promotion and are often best used when combined with official reports. Crowdsourced bicycling infrastructure data can be timely and facilitate comparisons across multiple cities; however, such data must be assessed for consistency in route type labels. Using social media, it is possible to track reactions to bicycle policy and infrastructure changes, yet linking attitudes expressed on social media platforms with broader populations is a challenge. New data present opportunities for improving our understanding of bicycling and supporting decision making towards transportation options that are healthy and safe for all. However, there are challenges, such as who has data access and how data crowdsourced tools are funded, protection of individual privacy, representativeness of data and impact of biased data on equity in decision making, and stakeholder capacity to use data given the requirement for advanced data science skills. If cities are to benefit from these new data, methodological developments and tools and training for end-users will need to track with the momentum of crowdsourced data.     

广西高速公路计重收费应用及改造设计要点

文章分析了高速公路实施计重收费的必要性,介绍了计重收费在广西高速公路的应用及改造设计的要点、难点,探讨了计重收费改造工程中的土建工程、安全设施及机电设施设计的相关措施。     

高速公路互通改扩建线形布设难点及处理方法研究

互通式立交改扩建是高速公路改扩建工程的重点和难点,做好其改扩建线形布设非常关键。文章采用比较性分析与规律性总结相结合的方法,分析了高速公路互通式立交改扩建工程线形布设的主要影响因素和普遍遇到的难点与处理方法,并以呼包高速公路呼和浩特市互通改扩建工程为实例,介绍了其改扩建线形布设的难点与解决措施。     

中国城市道路规划方位性问题研究

文章结合中国的传统建筑文化理念和现代科学原理,从历史文化、能源节约、环境保护、房地产定价、交通安全等多方面分析研究了城市道路在规划和设计时所应遵从的定向规则。     

北欧公路印象与启示

以人为本、尊重自然、适用完善是北欧公路的鲜明特点。本文介绍了北欧公路在总体设计、路线、路基路面、排水、桥遂、交通工程及服务设施、运营管理等方面的具体做法,并结合我国公路的现状提出了一些思路。     

Activity fragmentation,ICT and travel: An exploratory Path Analysis of spatiotemporal interrelationships

This paper focuses on the interrelationships between ICT, activity fragmentation and travel behaviour. The concept of fragmentation relates to how activities are spatiotemporally reorganized, by subdividing activities into smaller components that are then performed at different times and/or locations, in connection with ICT use. The association between ICT, activity fragmentation and travel relationships remains uncharted. Based on a two-day Dutch communication-activity-travel diary different associations between ICT use, paid work spatiotemporal fragmentation indicators and frequency of travel are specified and tested with Path Analysis Modelling accounting for sociodemographic and land use factors. The results demonstrate that the interrelationships between fragmentation, ICT and travel are quite complex. ICT and fragmentation apparently have a reciprocal relationship with mobile ICT use influencing the degree of spatial fragmentation whereas the usages of sedentary ICT are influenced by the degree of temporal fragmentation. Person-ICT attributes and ICT use mediate the participation in non-work activities, and can replace work and non-work travel. Fragmentation reduces work trips but at the same time restricts non-work personal travel possibilities and can reallocate time for leisure activity and travel.     

The role of public authorities

Advances in information technology and telecommunications are opening up the possibility of transforming the capture, application and dissemination of information on transport operations and road traffic, at the same time as growing congestion makes accurate and timely information more valuable than ever to users and managers. Because of open access to road networks, public authorities are bound to intervene in the field of travel information: in the provision of infrastructure, the handling of the information, the licensing of services, and the regulation of users affecting safety or social well-being. The paper discusses these rôles and the levels at which they may be exercised, with particular reference to standardisation issues in Europe and internationally.     

Resilience in railway transport systems: a literature review and research agenda

ABSTRACT

Critical infrastructure networks, such as transport and power networks, are essential for the functioning of a society and economy. The rising transport demand increases the congestion in railway networks and thus they become more interdependent and more complex to operate. Also, an increasing number of disruptions due to system failures as well as climate changes can be expected in the future. As a consequence, many trains are cancelled and excessively delayed, and thus, many passengers are not reaching their destinations which compromises customers need for mobility. Currently, there is a rising need to quantify impacts of disruptions and the evolution of system performance. This review paper aims to set-up a field-specific definition of resilience in railway transport and gives a comprehensive, up-to-date review of railway resilience papers. The focus is on quantitative approaches. The review analyses peer-reviewed papers in Web of Science and Scopus from January 2008 to August 2019. The results show a steady increase of the number of published papers in recent years. The review classifies resilience metrics and approaches. It has been recognised that system-based metrics tend to better capture effects on transport services and transport demand. Also, mathematical optimization shows a great potential to assess and improve resilience of railway systems. Alternatively, data-driven approaches could be potentially used for detailed ex-post analysis of past disruptions. Finally, several rising future scientific topics are identified, spanning from learning from historical data, to considering interdependent critical systems and community resilience. Practitioners can also benefit from the review to understand a common terminology, recognise possible applications for assessing and designing resilient railway transport systems.     

Modeling and forecasting household energy consumption and related CO2 emissions integrating UrbanSim and transportation models: an Atlanta BeltLine case study

Reducing energy consumption and controlling greenhouse gas emissions are key challenges for urban residents. Because urban areas are complex and dynamic, affected by many driving factors in terms of growth, development, and demographics, urban planners and policy makers need a sophisticated understanding of how residential lifestyle, transportation behavior, land-use changes, and land-use policies affect residential energy consumption and associated CO₂ emissions. This study presents an approach to modeling and simulating future household energy consumption and CO₂ emissions over a 30-year planning period, using an energy-consumption regression approach based on the UrbanSim model. Outputs from UrbanSim for a baseline scenario are compared with those from a no-transportation-demand model and an Atlanta BeltLine scenario. The results indicate that incorporation of a travel demand model can make the simulation more reasonable and that the BeltLine project holds potential for curbing energy consumption and CO₂ emissions.     

Emergence of resilience as a framework for state Departments of Transportation (DOTs) in the United States

State Departments of Transportation (DOTs) in the United States are responsible for a large portfolio of transportation modes and services, including passenger and freight systems. These responsibilities include operations under routine conditions and during incidents and events that result from various natural and human-caused hazards. During unexpected events, disruptions and reductions in service result in requiring the reallocation and reassignment of personnel, modal, and economic resources. To better prevent and respond to the effects of service disruptions, the concept of resilience has emerged as an important framework, within which, DOTs across the United States are using to plan for the occurrence of threats. In this paper, the key findings of recent reviews of literature and practice related to resilience among state DOTs in the United States are summarized. The review effort focused on a range of risks faced by transportation agencies including climate change, terrorism, cyber-attacks, and aging infrastructure and the ways in which DOTs are confronting them in practice. The topics of this paper range from the fundamental, including definitions of transportation resilience; to the more complex such as examinations of risk, vulnerability and threats; to the most sophisticated topics including administrative-level efforts to conceptualize evolving transportation planning and policies within a resilience framework.