广西公路典型地质灾害特征与易发性评价

文章通过调查分析广西干线公路地质灾害的类型、发育特征与形成机制,采用定性、半定量的方法,对崩塌、滑坡、不稳定斜坡等典型灾种的易发性开展分段评价,为做好典型地质灾害防治决策、保障公路安全提供参考。     

南平市安丰水厂后山水毁滑坡特征及病害整治

本文以2010年南平市抗洪抢险中最典型最复杂的地质灾害点——安丰水厂后山水毁滑坡为例,介绍了特殊工况下的滑坡应急处理措施和综合治理方法,并对滑坡处理过程中的问题进行探讨,可为紧急情况滑坡治理提供参考。     

广西干线公路地质灾害危险性评估及防治对策

广西干线公路地质灾害频发,尤以斜坡类灾害为主,文章通过对广西国省干线105处重大地质灾害隐患点及42段地质灾害多发路段进行危险性评估,分析了广西干线公路地质灾害的类型、分布特征及危险程度,并结合广西干线公路地质灾害防治现状,提出针对性的防治对策,为减少公路地质灾害的发生和提高安全通达能力提供方法依据.     

广西公路地质灾害智能监测系统研究

为实现智能化管理与监控预警,文章对广西干线公路典型地质灾害数据进行空间数据库建设整理,并应用ArcGIS的空间数据统一管理和组织功能,拓展系统预警和敏感性分析模型的应用范围,建立了一个比较完善的、面向公路沿线的地质灾害监测预警管理系统,为及时了解公路地质灾害的发生与发展情况、针对性地采取防治及预警对策、降低损失和保障公路安全营运提供技术支持手段.     

川渝地区山地管道主要地质灾害成因及工程治理

为了研究川渝地区山地油气管道的主要地质灾害,现场勘察该地区某2条天然气管道的44个地质灾害点,统计分析得出该地区管道的主要地质灾害是崩塌和台田地水毁。分析2种主要地质灾害的产生机理,提出了治理措施。结果表明:对于川渝地区山地管道,必须重视崩塌和台田地水毁,提前采取相应的防控对策,防止对管道造成损害。     

国道227线扁都口至大通地质灾害特征及防治措施

根据G227沿线野外调查资料,对沿线地质灾害类型、特征、成因及其防治措施进行了较详细分析,提出线路改建过程中应注意的几个问题.     

贵州省普通国省干线及农村公路承灾体普查工作与风险点发育分布特征分析

结合贵州省普通国省干线及农村公路承灾体风险普查工作,对其风险点发育分布特征进行深入分析,以完善公路承灾体风险点和基础设施属性数据库,查明全省国省干线及农村公路风险点数量、类型、风险等级及发育分布特征,为公路地质灾害风险管控及后续自然灾害综合风险评估与区划提供详实的基础资料。     

库区岸坡稳定性分析及整治措施研究

库区地质灾害的形成主要是由于大气降雨、工程建设以及水利工程分级蓄水后可能诱发滑坡、崩塌、泥石流及地面塌陷、沉降等造成的。为了探究库区的地质灾害及其成因、破坏机理,保证库岸地区的安全及经济需要,本文以重庆市区域内某库区为研究背景,(1)按照岸坡岩土类型、破坏模式及塌岸强烈程度等特征,结合现场调查及勘探揭示的情况将该勘察区库分为Ⅰ段～Ⅵ段,并对该库区地质灾害体基本特征及变形机制进行了分析;(2)以库岸区段Ⅱ段为例,通过选取区段具有代表性的3个剖面,按照三种不同的工况对选取的剖面进行稳定安全系数及剩余下滑力进行计算,结合计算结果,评价该库岸边坡稳定性;(3)根据塌岸稳定性的计算结果,结合调查的实际情况等,提出库岸塌岸的整治措施与方案,并对方案进行经济社会效益分析,以期为以后库区的地质灾害体预防与治理工作提供一定的参考和借鉴。     

长距离天然气管道地质灾害风险区划

地质灾害引起的天然气管道失效和破坏非常严重,对地质灾害情况下天然气管道进行安全可靠性和风险性评价是一项非常重要的工作.由于地质灾害具有区域性,因此地质灾害评价的任务之一是划分地质灾害危险区.文中综述了天然气管道地质灾害风险区划的研究现状,分析了区划的目的及流程、区划的主要内容,提出了按地质灾害种类、按风险程度值和按地质...     

巴万高速典型边坡危岩分析与处治方法研究

随着国民经济的快速发展,跨山区的高速交通愈发受到重视,而山区地质灾害频发,边坡危岩属于山区的典型地质灾害,因此,山区高速公路尤其需要做好边坡危岩的处治工作。基于此,本文对边坡危岩的失稳方式进行了讨论,并根据巴万高速某边坡危岩工程实例,提出采用柔性主动防护网技术与静态膨胀破碎法相结合的施工方案进行边坡危岩处治,并对该方案的工艺流程进行了介绍,为同种类型的边坡危岩处治提供了思路。     

A new approach for modeling of Fundamental Diagrams

According to the intra-vehicle interaction, a traffic flow can generally be divided into three homogeneous states (1) that of free driving, (2) that of bunched driving, and (3) that of standing. The parameter describing the state of free driving is the desired speed, for the state of bunching it is the intra-vehicle gaps (time headway) within the convoy and the mean speed of the convoy, and for the state of standing it is the maximum jam density. These are the most essential parameters which do not depend on the actual traffic situation.This paper introduces a new model which considers the Fundamental Diagram (equilibrium speed–flow–density relationship) as a function of the homogeneous states. All traffic situations in reality can be considered as combinations of the homogeneous states and therefore can be described by the essential parameters mentioned above. The non-congested (fluid) traffic is a combination (superposition) of the states of free driving and bunched driving, the congested (jam, stop, and go) traffic is a combination of the states of bunched driving (go) and standing (stop). The contribution of the traffic states within the differently congested traffic situations can then be easily obtained from the queuing and probability theory. As a result, Fundamental Diagram in all equilibrium traffic situations is derived as simple functions of the essential parameters.According to the new model the capacity of freeways and rural highways can be determined by measuring the essential parameters. This is much easier than measuring the capacity directly.Furthermore, the probabilities of the various traffic states can be obtained from the new model. This leads to new possibilities in real-time controlling and telematics.The new model is verified by comprehensive measurements carried out on freeways and rural highways in Germany.     

Vulnerability and resilience of transport systems – A discussion of recent research

The transport system is critical to the welfare of modern societies. This article provides an overview of recent research on vulnerability and resilience of transport systems. Definitions of vulnerability and resilience are formulated and discussed together with related concepts. In the increasing and extensive literature of transport vulnerability studies, two distinct traditions are identified. One tradition with roots in graph theory studies the vulnerability of transport networks based on their topological properties. The other tradition also represents the demand and supply side of the transport systems to allow for a more complete assessment of the consequences of disruptions or disasters for the users and society. The merits and drawbacks of the approaches are discussed. The concept of resilience offers a broader socio-technical perspective on the transport system’s capacity to maintain or quickly recover its function after a disruption or a disaster. The transport resilience literature is less abundant, especially concerning the post-disaster phases of response and recovery. The research on transport system vulnerability and resilience is now a mature field with a developed methodology and a large amount of research findings with large potential practical usefulness. The authors argue that more cross-disciplinary collaborations between authorities, operators and researchers would be desirable to transform this knowledge into practical strategies to strengthen the resilience of the transport system.     

Factors affecting the use of bus and rail services in a deregulated environment

In 1987, the NSW Government commenced deregulation of the long-distance bus industry in NSW. This immediately led to greater inter-modal competition and contestability within the context of changing passenger markets.This study utilises categorical data analysis methods to examine the emerging passenger markets of inter-modal competitors (bus and rail) and to assess the relative importance of socioeconomic and travel related variables which affect the use of bus and rail services along the high volume Sydney-Canberra and Sydney-North Coast corridors.Conclusions from the study indicate varied passenger markets within a relatively new contestable environment which are mode and corridor specific. Results are indicative of the need for competitors to develop marketing strategies conducive to the demands of the travelling public in order to enhance viability and commercial opportunities.     

国外铁路运营安全效益评价现状及启示

铁路运输在国民经济运行中发挥着重要作用,各国铁路公司都非常重视对铁路运营、安全、效益的管理及评价。国外铁路经过两个世纪的发展,积累了丰富经验,通过分析美国、日本、欧洲等国家和地区的普速、高速铁路,在运营效率评价、运营安全评价、服务质量评价、经营效益评价、安全保障法律法规建设和第三方评价机构发展等方面的现状,从客户服务质量评价、安全评价标准体系建立、效率效益导向的经营效益评价机制建设、第三方专业评价机构发展等维度,总结对我国高速铁路运营安全效益评价的经验借鉴及启示。     

Walking,cycling and the urban form: A Heckman selection model of active travel mode and distance by young adolescents

Physical inactivity of children and adolescents is a major public health challenge of the modern era but, when adequately promoted and nurtured, active travel offers immediate health benefits and forms future sustainable and healthy travel habits. This study explores jointly the choice and the extent of active travel of young adolescents while considering walking and cycling as distinct travel forms, controlling for objective urban form measures, and taking both a “street-buffer” looking at the immediate home surroundings and a “transport-zone” looking at wider neighborhoods. A Heckman selection model represents the distance covered while cycling (walking) given the mode choice being bicycle (walk) for a representative sample of 10–15 year-olds from the Capital Region of Denmark extracted from the Danish national travel survey. Results illustrate the necessity of different urban environments for walking and cycling, as the former relates to “street-buffer” urban form measures and the latter also to “transport-zone ” ones. Results also show that lessening the amount and the density of car traffic, diminishing the movement of heavy vehicles in local streets, reducing the conflict points with the density of intersections, and intervening on crash frequency and severity, would increase the probability and the amount of active travel by young adolescents. Last, results indicate that zones in rural areas and at a higher percentage of immigrants are likely to have lower probability and amount of active travel by young adolescents.     

The quality of survey data: Telephone versus face-to-face interviews

Those designing surveys and producing data have always been concerned about its quality. The increasing stringency of the financial constraints which affect public authorities and the increased scope of involvement in the regulation of urban travel has led us to pay even greater attention to the quality of data. This issue is frequently covered in the literature on survey methods. However, comparisons between different survey methods are more rarely conducted. The decision to conduct such an analysis is partly the result of the development of telephone use to the detriment of other survey modes in many countries and also the development of Computer-Aided Telephone Interviewing (CATI) which facilitates the running and monitoring of the survey.This paper examines several aspects of this question in order to compare the performance of telephone and face-to-face interviews. The first aspect is the representativeness of the sample, and therefore relates mainly to the issue of nonresponses and the choice of a sample base. The second concerns the accuracy of the information and involves the choice of a survey area and the recording of all trips, including short-distance travel. Finally, the quality of data is obviously determined by the quality of the responses given by those interviewed.The answers we give frequently depend on the objective of the surveys, which leads us to put forward a table which summarizes the performance of telephone and face-to-face interviews on the basis of the main objective of the survey. Broadly, the telephone seems to be the favoured tool for surveys in the area of transport planning and surveys which aim to provide data for forecasting models, mostly on the grounds of cost. However, face-to-face techniques are often preferred for surveys which aim to discover and analyze the factors which explain individual travel behaviour.     

Bicycle parking: a systematic review of scientific literature on parking behaviour,parking preferences,and their influence on cycling and travel behaviour

ABSTRACT

Cycling is experiencing a revival in many cities. Research has focused on the determinants of cycling – in particular the role of the built environment and road infrastructure. Bicycle parking has received little attention – even though bicycles are parked most of the time. This article reviews the scientific literature on bicycle parking and identifies existing gaps in research and knowledge. The review analyses 94 peer-reviewed papers identified through a search in Scopus and Web of Science, in December 2017. The annual number of papers increased 15-fold between 1995 and 2017. Overall, the level of evidence on the importance of bicycle parking is limited. The majority of studies are based on cross-sectional data with the presence of parking as a binary independent variable. Most studies focus on bicycle parking at public transport stops and at work places. Few studies report on bicycle parking throughout cities, and hardly any on parking at residential locations. Bicycle parking supply and quality appears to be a determinant of cycling for current and potential cyclists. Our findings can serve as input for an evidence-based debate on the role of bicycle parking. For practitioners, our research supports investment in bicycle parking, but acknowledges that a proper evaluation of such initiatives needs to be conducted to increase the level of evidence.     

Financing urban rail projects: The case of Los Angeles

This paper describes the potential use of the financing strategy of value capture or benefit assessment for an urban mass transportation project. The paper describes the legal background to the use of benefit assessment, and the process of implementation for the first construction phase of the Los Angeles Metro Rail project. The process of developing the benefit assessment structure was a consultative one, utilizing technical inputs from a team of specialist consultants, a task force consisting of major developers and property owners in the affected area, and politicians representing many of the interests in the region. The initial benefit assessment districts were set up to raise $130 million of the cost of the first 4.4 miles of the rail project, and are based on the benefits accruing to certain categories of property in the vicinity of stations. The assessment would be collected for about 18 years and bonding would be used to provide the capital at the time of construction.The paper describes the procedure for setting boundaries, the structuring of the assessment rates, the definition of benefiting properties, and the uses and tenure of the assessment. In almost all cases, the theory of value capture indicated a different result than was achieved from a consensus of the task force, and the nature of these differences is explored in the paper. The establishment of the benefit assessment districts withstood early court challenges, but has subsequently been appealed and was overturned on appeal. Action is pending with the Supreme Court currently, and efforts are also underway to pass new legislation to deal with some of the issues raised in the court proceedings.     

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.