郑万高铁重庆段隧道二次衬砌施工质量管理实践

隧道二次衬砌的施工质量关系着铁路运营安全。文章以郑万高铁重庆段隧道二次衬砌施工为背景,针对二次衬砌质量缺陷问题,对工装设备、施工工艺和管理措施进行了优化,特别是针对初期支护平整度、防水板铺设、台车布料、混凝土振捣、拱顶防脱空监控、施工缝处理、止水带安装等方面采取了一系列改进措施,实现了隧道二次衬砌施工横向到边、纵向到底的有效管理,规范了作业标准,提升了施工质量,取得了良好的施工效果。     

Comparison of car ownership models

Car ownership models found in the academic literature (with a focus on the recent literature and on models developed for transport planning) are classified into a number of model types. The different model types are compared on a number of criteria: inclusion of demand and supply side of the car market, level of aggregation, dynamic or static model, long‐ or short‐run forecasts, theoretical background, inclusion of car use, data requirements, treatment of business cars, car‐type segmentation, inclusion of income, of fixed and/or variable car cost, of car quality aspects, of licence holding, of sociodemographic variables and of attitudinal variables, and treatment of scrappage.     

Development and evaluation of a knowledge-based system for traffic congestion management and control

This paper describes a real-time knowledge-based system (KBS) for decision support to Traffic Operation Center personnel in the selection of integrated traffic control plans after the occurrence of non-recurring congestion, on freeway and arterial networks. The uniqueness of the system, called TCM, lies in its ability to cooperate with the operator, by handling different sources of input data and inferred knowledge, and providing an explanation of its reasoning process. A data fusion algorithm for the analysis of congestion allows to represent and interpret different types of data, with various levels of reliability and uncertainty, to provide a clear assessment of traffic conditions. An efficient algorithm for the selection of control plans determines alternative traffic control responses. These are proposed to an operator, along with an explanation of the reasoning process that led to their development and an estimation of their expected effect on traffic. The validation of the system, which is one of only few examples of validation of a KBS in transportation, demonstrates the validity of the approach. The evaluation results, in a simulated environment demonstrate the ability of TCM to reduce congestion, through the formulation of traffic diversion and control schemes.     

The role of accident exposure in transport system safety evaluations II: Group exposure and induced exposure

Part I of this paper has argued that any meaningful evaluation of transport system safety must include a consideration of the exposure to accidents, and has demonstrated the use and limitations of several measures of exposure at intersections and along links of the network. To complement this treatment of site exposure, this part of the paper will describe the use of group exposure measures in the assessment of risks incurred by people within particular population groupings. The use of induced exposure measures is also briefly reviewed.     

Use of magnetic monitoring of vehicles for proactive strategy development

The proactive operational strategy in the transport system which is a parallel concept associated with the Intelligent Transportation System (ITS) seems to be modern and right direction of development. However, the basis for its operation is the “information” in the broad sense of the term, on the functioning of the transport system itself. As new technologies develop, there emerge new opportunities of putting to use a wide array of sensors which can deliver more complete traffic data but using complex matrix of sensors is often unjustified economically and confusing. The paper proposes use of magnetometers as an interesting alternative to pass the requirements of simplicity of application, minimum costs and maximum of acquired information. The process of obtaining the information requires analysis of the quantitative and qualitative changes of the magnetic field. The conducted analyses demonstrate the possibility of using the passive magnetic methods for the purpose of monitoring of vehicles. Placement of the magnetic sensor bear out an important issue and was also discussed. During the experimental research it has been proven that passive magnetic methods enable obtaining the information on the movement of a vehicle as well as on the vehicle itself. Estimations of such values as: vehicle’s moving direction, velocity, dimensions, clearance or mass having ferromagnetic properties and even the state of strain in a vehicle’s structure were confirmed in practice. In addition thanks to magneto-mechanical effects the theoretical possibility of assessing the stress occurring in the components of vehicles, which could be indicative of the volume of cargo carried. Moreover, the crash experiment showed the possibility of a collision detection using magnetic signal. The need for obtaining information increases from year to year, with information becoming the biggest asset which enables both development and effective use of the transport system. Included researches, proofs emerging opportunity of more extensive use of magnetic sensors and the passive magnetic methods which could be applied in the modern transportation system.     

Towards modal choice decision-making models: A case study of Lagos state transport corporation bus riders

Identification of the socioeconomic factors which affect the demand for buses, and the analysis of the use of the other transport modes by bus users are the two main objectives of this article. Work and school trips are highlighted as being very important trip purposes in Lagos metropolis by the multiple discriminant analysis model. It identifies mode of transport, distance, travel time, reliability, and the number of stops as significant mode choice variables. Multiple linear regression models for work and school trips identify mode of transport, transfort fare, travel time, annual income, and crew behaviour as significant variables in the choice of transport mode. These findings support the two alternative hypotheses of the study that the choice of bus is related to the individual perception of the quality of service of the different modes and that socioeconomic characteristics of the riders influence the patronage of buses. The attention of policy makers for the 22 transport corporations that operate inter-and intra-urban services in all the 21 states and the federal capital of Abuja in Nigeria is drawn to the importance of these variables for decisions.     

A review of separate and joint strategies for the use of data on revealed and stated choices

This paper examines recent developments in household travel surveys that collect data for use in transportation planning and modeling efforts. The paper then introduces the notion of a total survey design and elaborates on what is meant by this concept. This is done first in the context of standard surveys of revealed choices. The paper discusses aspects of content and respondent burden and illustrates the potential to reduce respondent burden through careful consideration of content, question design, and question ordering. The paper also explores some issues of survey "friendliness" particularly with respect to activity surveys versus time-use surveys, with some observations about the potential of time-use surveys to eliminate some of the burden and content problems of previous diary designs. The remainder of the paper concentrates on the issue of collecting stated-response data and examines two alternative methods for collection: simultaneous collection of the contextual information and "on-the-fly" development of the alternatives for the stated-response questions, or sequential collection of contextual data and development of the stated-response questions. The paper also addresses issues of respondent burden that arise in the administration of stated-response surveys. The paper concludes with exploration of some of the reasons for collecting stated-response data, with particular emphasis on the US situation. In conclusion, the paper stresses again the need for a total design concept for collection of stated-response data, as well as for the simpler collection of more standard revealed choice data.     

A measure of linked‐trip accessibility

The concept of accessibility has been variously interpreted as being the “nearness to places,” the “nearness to activities” and more recently the “ease of participating in activities.” With each of these qualitative interpretations, there has also been a variety of quantitative definitions of accessibility. This paper shows that many of the proposed definitions of accessibility can in fact be gathered together to form a spectrum of accessibility measures. These measures differ with respect to the factors included in their formulation and their degree of behavioural interpretation.

Existing measures of accessibility are shown to be deficient in one major aspect. That is, they assume that for any one measure of accessibility there is but one origin of trips. Thus, in estimating the accessibility of a point within a region it is assumed that all potential trips, which contribute to the accessibility of that point, start from that single point. In view of the considerable amount of evidence demonstrating the widespread, and increasing, occurrence of trip‐linking such a proposition must be viewed as being rather doubtful.

In the light of this, the paper proceeds to develop a measure of accessibility which explicitly accounts for the linking of trips. The implications of this measure, compared to a conventional unlinked‐trip accessibility measure, are discussed as are some problems which are foreseen in the practical implementation of such a measure.     

Unbalanced development of inter-provincial high-grade highway in China: Decomposing the Gini coefficient

This study discusses the unbalanced development of Chinese inter-provincial high-grade highway from 1997 to 2013. It does so from the viewpoint of the inter-provincial Gini coefficient based on per capita mileage of high-grade highway, which is decomposed according to such dimensions as the increment of the Gini coefficient, the Gini coefficient of different types of high-grade highway, and the Gini coefficient between and within inland and coastal areas. The Gini coefficient of China’s per capita mileage of inter-provincial high-grade highway shows a declining trend year by year. According to the results from the decomposition of the contribution rate of different types of high-grade highway, the unbalanced development of inter-provincial high-grade highway is caused mainly by that of first- and second-grade highway. According to the results from the decomposition related to the increment of the Gini coefficient of China’s per capita mileage of inter-provincial high-grade highway, the decrease of the Gini coefficient from 1997 to 2013 was mainly the result of balanced distribution of high-grade highway among regions in China. According to the results from the decomposition of the Gini coefficient between and within inland and coastal areas, the unbalanced development of inter-provincial high-grade highway in China from 1997 to 2013 was caused mainly by the unbalanced development of inter-provincial high-grade highway in inland areas. Therefore, the authors argue that the government should pay more attention to protecting the environment and providing a suitable scale of highway network, which could promote long-term sustainable development.     

A study of interstate motor carrier vehicle miles of travel

This article summarizes the evaluation results of six data sources in terms of their ability to estimate the number of commercial trucks operating in interstate commerce and their vehicle miles of travel by carrier type and by state. The six data sources were: (a) Truck Inventory and Use Survey of the U.S. Bureau of the Census; (b) Nationwide Truck Activity and Commodity Survey of the U.S. Bureau of the Census; (c) National Truck Trip Information Survey of the University of Michigan Transportation Research Institute; (d) Highway Performance Monitoring System of the Federal Highway Administration, U.S. Department of Transportation; (e) International Registration Plan of the American Association of Motor Vehicle Administrators; and (f) State fuel tax reports from each individual state and the International Fuel Tax Agreement. Evaluation results concluded that none of the data sources by themselves were capable of providing reliable estimates at the state level. Although several attempts were made to combine the strengths of different data sources so that reliable estimates could be generated, none of them were successful. Data inconsistency and incompatibility contributed primarily to the failures. Although several of the six data sources by themselves could provide estimates at the national level, each had limitations. As a result of these findings, two cost-effective methodologies were proposed to estimate the number of commercial trucks operating in interstate commerce and their vehicle miles of travel by carrier type. Neither method required collecting additional data.     

震旦系混合岩隧道防塌防掉块几项关键技术

兰渝线黑山隧道震旦系混合岩地层占整条隧道长度93%,综合考虑其岩性的特性,结合施工现场地质状况,文章主要以Ⅳ级围岩为例,从爆破方案、支护措施、加强施工工艺、围岩监控量测、超前地质预报及仰拱二次衬砌方面,总结震旦系混合岩预防塌方掉块的几项关键技术。     

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.     

鲁宁输油管道经济清管周期的确定

介绍了原油在输送过程中蜡的析出规律,建立了当量管径与输油天数的数学模型,从而确定出管道最佳的经济清管周期。     

基于GIS的我国近海外来生物入侵时空演变数据库系统构建方案研究

海洋生物入侵已成为世界海洋生态环境面临的四大问题之一。我国目前针对海洋外来生物入侵的数据资料缺乏,且未形成时空分布的数据系统。本文通过文献查找、资料收集与历史数据整理,现场调研等多种手段,拟掌握我国近海外来生物入侵时空演变历史及现状,提出基于GIS软件的数据库系统的建设方案。本系统的建设可实现海洋入侵物种查询,外来入侵物种判定、不同时期下,外来生物入侵我国近海海域的发生地点、入侵种类、灾害发生时间、灾害影响的对比分析等功能。     

Urban public transport in Europe: Technology diffusion and market organisation

Technological change and incremental technology, at various levels, are believed to have played an important role in the success of urban public transport in Europe. In this paper, a historical overview of the evolution of different transport modes across different European cities is presented. Our major concern is with the processes of diffusion of urban transport modes in European cities and, in particular, with the factors, mainly of an economic nature, that may explain their rates of adoption across Europe. Among these factors, special attention is given to the role played by the dimension and organisation of public transport markets in the rates of adoption of different public transport modes. The main conclusion of the paper is that the success of the introduction of a new transport mode appeared to be mainly related to its ability to provide cheaper and more reliable transport services compared with previous transport modes, and that, in the case of the electric tram, this was achieved by transforming of the structure of the market relating to this urban transport mode into monopolies.     

Hybrid cyclicity: Combining the benefits of cyclic and non-cyclic timetables

We propose a new type of timetable that would combine both the regularity of the cyclic timetables and the flexibility of the non-cyclic ones. In order to do so, several combinations of the two timetables are considered. The regularity is incorporated in their design and the flexibility is evaluated using the passenger satisfaction (in monetary units). Each of the tested timetables is constructed using the Passenger Centric Train Timetabling Problem (PCTTP), that is solved using a simulated annealing heuristic. Note that the PCTTP, unlike the traditional Train Timetabling Problem (TTP), does not take into account the conflicts among trains. The aim of the PCTTP is to design such timetables that the passengers’ satisfaction is maximized and it remains the aim of the TTP to remove any potential conflicts. The performance of each of the considered timetables is assessed on the real network of Israeli Railways. The results of the case study show that our proposed hybrid cyclic timetable can provide the benefits of the cyclic and the non-cyclic timetable simultaneously. This timetable consists of 75% of cyclic trains (securing the regularity of the service) and of 25% of non-cyclic trains (deployed as supplementary trains during the peak hours and capturing the demand fluctuation). The level of the passenger satisfaction of the hybrid cyclic timetable is similar to the level of the non-cyclic one, which has about 18.5% of improvement as compared to the purely cyclic one.     

The identification of factors influencing destination choice: An application of the repertory grid methodology

A common problem of all cognitive-behavioural models of destination choice is that of the identification of factors influencing the behaviour of interest. This paper considers the applicability of Kelly's repertory grid methodology to identify the factors influencing consumer choice of shopping centres. Firstly, some methodological issues in the assessment of the relative importance people attach to certain variables in deciding where to shop are discussed. Secondly, the main findings of an application of the repertory grid methodology are presented. The paper concludes by discussing some implications of the measurement of the determinants of choice behaviour and the construction of mathematical models of destination choice.     

基于Adams和Matlab联合的汽车悬架系统仿真分析

伴随着虚拟样机技术的不断发展,虚拟物理模型与控制模型联合仿真技术日趋成熟。文中利用ADAMS软件,建立了二分之一车体四自由度汽车主动悬架的虚拟模型。通过集成车辆主动悬架系统的动力学方程,搭建了基于ADAMS和MATLAB联合的汽车悬架系统仿真平台。在此基础上,比较分析了某轿车汽车车身垂直加速度响应和车身俯仰角加速度响应,该模拟结果与文献[1]数学模型的结果基本吻合,从而验证了系统仿真平台正确性。     

Application of BIM Technology in the Construction Management of a Metro Station北大核心CSCD

For the restricted construction site of a Beijing metro station surrounded by many important buildings and characterized by complex staggered underground pipelines, many construction difficulties and a high level of re-quired management, settlement monitoring is necessary for the sake of construction safety. A 3D model of the metro,a model of the specially shaped structure and models of many details of the metro were established using the BIM technique, allowing for: creation of a 3D presentation, extraction of construction quantities, construction conse-quence optimization, guidance of construction endeavors, simulation of the construction process, 4D dynamic con-struction management and 4D dynamic settlement monitoring. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

相邻隧道扩挖施工影响分析

采用现场实测和数值计算方法,对乌鞘岭志留系地层板岩夹千枚岩地段左线隧道扩挖施工引起右线隧道的围岩状况和既有支护结构的受力变化进行分析。结果表明,两相邻隧道在不同施工阶段进行导洞开挖和扩挖前后存在一定程度的群洞效应作用,扩挖施工引起右线隧道向左线隧道产生了较小的侧移;在左线隧道扩挖后,右线隧道既有衬砌的接触压力、结构轴力和弯矩均有明显增大,但衬砌结构的安全系数均满足规范要求,处于安全状态。