大型沉管隧道管段沉放施工技术

以上海外环沉管隧道管段沉放对接为例,介绍"双三角形"布置锚缆管段平面定位和双浮箱四点竖向吊沉系统及设备,简述管段沉放对接工艺流程及测量定位技术,最后分析管段沉放对接施工过程中遇到的问题.     

沉管隧道管段预制施工技术

文章结合广州生物岛—大学城沉管隧道工程实例,介绍沉管隧道其分项工程管段预制的施工技术,以及施工过程中对预制质量的控制。管段预制是沉管隧道施工的主要环节,对其施工技术、预制质量的要求较高。管段预制结构的尺寸、预埋件安装精度、混凝土容重及干舷值控制直接关系到管节浮运、沉放。管段预制混凝土应满足不渗、不裂、不漏的设计要求,并保证其耐久性及使用寿命的设计要求。因此,在管段预制施工过程中施工技术对质量的控制及保证尤为重要。     

沉管隧道测量技术

文章针对大型曲线沉管隧道的特点,论述了曲线沉管隧道的平面及高程控制测量、管段特征点标定测量、管段沉放测量,以及管内测量的方法,并给出了相应的计算公式.     

沈家门港海底沉管隧道设计介绍

沉管法是修建水下隧道的一种先进施工方法,其设计需考虑结构、施工工艺、水文地质条件、运营等众多因素的影响。针对隧道工程和水文地质、沉管结构、管段沉放水流阻力等条件,以及系缆柱、接头防水、最终接头、工程耐久性等措施,对沈家门港海底沉管隧道工程的设计进行了分析。分析结果表明:沉管管段既要满足结构力学要求,又要满足施工中起浮运输及运营期抗浮、稳定性、耐久性要求,综合考虑各种因素才能设计出符合要求的沉管隧道结构。     

沉管隧道技术的应用与现状分析

文章回顾了沉管隧道技术的发展历程和国内外的应用概况;并对越江隧道工程中采用的不同施工方法、隧道与桥梁方案的比较以及沉管隧道设计和施工过程中的地基处理、管段浮运与沉放和管段防水等关键技术进行了分析和论述;最后,介绍了沉管技术在国内的应用情况,分析了沉管隧道的应用前景,并指出随着地下空间的开发利用,沉管隧道因其独特的优越性必将会越来越受到青睐。     

沉管隧道临时支承系统设计与施工控制

文章论述了沉管隧道管段临时支承系统的三点支承、四点支承、五点支承等几种主要形式,并进行了分析对比;同时介绍了五点式支承系统在越南西贡东西高速公路过江沉管隧道工程中的应用情况以及支承系统的设计与施工控制。研究结果及工程实践均表明:五点式支承系统在管段安装后始终能保证有三个支承点,可确保管段水下姿态稳定,同时具有更高的安装精度,尤其适合线路长、管段多的沉管隧道。     

浅谈沉管隧道起浮与抗浮设计

沉管隧道结构设计与普通隧道的结构设计不同,沉管隧道管段不仅要满足结构受力要求,也要满足起浮及浮运期间的干舷高度,以及运营期间的抗浮安全系数要求.文章根据影响管段干舷及抗浮的主要因素,浅谈沉管管段起浮与抗浮设计,为以后沉管隧道管段设计提供参考.     

港珠澳工程沉管隧道施工技术介绍

沉管法因其施工方式先进,可操作性强,已逐渐成为修建水下大型隧道的一种成熟的施工工法。概要介绍了我国沉管隧道的现状与发展过程;以港珠澳工程沉管隧道施工为例,详细介绍了基槽开挖、基础处理、超大管节预制及浮运沉放的施工技术;对沉管隧道所应用的新工法、新材料、新机具、新工艺等关键技术进行了分析。     

沉管隧道管段接头防水研究--数值模拟分析

从沉管隧道施工的特点可知,管段与管段之间的接头防水十分重要,若接头之间水密性不能得到保证,会危害整条隧道的安全使用.文章通过沉管隧道管段接头首道防线,也是最重要防线的GINA止水带的数值模拟研究,对GINA止水带不同压缩量下的防水能力、压缩剪切情况下的防水能力及耐久性等情况进行了模拟、计算、分析.望对今后类似的大型沉管隧道管段接头的设计、施工有所帮助.     

上海外环沉管隧道管段基础压砂法施工技术

管段基础处理是沉管法隧道施工中的重要环节,文章以上海外环沉管隧道管段基础处理为工程背景,对压砂法的机理及其试验进行说明,对压砂施工的流程及工艺、安全与质量的控制方法进行了介绍,并对管段的沉降进行了分析.     

交通与土地利用一体化的主要内容与实现途径

本文在分析现代城市病产生原因的基础上,从交通的角度提出了解决现代城市病的对策思路。在此基础上,阐述了交通一体化的内容、交通与土地利用一体化的关键和实现途径。作者提出防止现代城市病的关键是混合土地使用、严格控制通勤圈半径和建立公交主导的绿色交通系统。     

Resilience and accessibility of Swedish and Dutch municipalities

Recent years have shown a rising popularity of the concept of resilience—both theoretically and empirically—in complex systems analysis. There is also a rising literature on resilience in the transport and spatial-economic field. The pluriform interpretation of resilience (e.g., engineering vs. ecological resilience) is related to methodological differences (e.g., stability in dynamics vs. evolutionary adaptivity). But in all cases the fundamental question is whether a complex system that is subjected to an external shock is able to recover, and if so, to which extent. The present paper [Based on presentation from cluster 6 (Accessibility) of the Nectar 2015 conference in Ann Arbour, USA.] aims to add a new dimension to resilience analysis in spatial systems, by addressing in particular the relationship between spatial accessibility at a municipality level and the resilience outcomes of the spatial system concerned. It does so by investigating to which extent accessibility of Swedish and Dutch municipalities has mitigated the local shock absorption from the recent economic recession. In our study the shock absorption capacity of municipal accessibility is estimated by analysing the relevant resilience indicators for the period concerned. In this context, conventional resilience indicators based on either multivariate complex data (in particular, the Foster Resilience Capacity Index) or employment data (in particular, the Martin Resilience-Employment Index) are confronted with spatial connectivity data based on local accessibility measures, so that geographical mobility may be regarded as one of the shock-mitigating factors. The empirical analysis is carried out for two countries which have both proven to be rather shock-resistant during the recent economic crisis, viz. Sweden and The Netherlands. Clearly, the geographical structure of these countries forms a sharp mutual contrast, viz. a spatially dispersed economy with a few distinct urban concentrations versus a spatially dense economy with one major metropolitan centre (the Randstad), respectively. Our experiments are carried out for the 290 municipalities in Sweden and 40 COROPs in The Netherlands. Our research findings show relevant and new insights into differences in the local recovery potential in Sweden and The Netherlands.     

铁路隧道防排水现状与思考

文章针对铁路隧道的防排水现状,指出了目前在防排水设计与施工中存在的问题和难点,并进行了具体分析,在防水类型的选择、地下水处理、衬砌外围结构防水、内衬砌防水等方面提出了铁路隧道防排水的措施和建议。     

材料节约与循环利用专项行动计划技术成果简介

当前,加快建设资源节约型、环境友好型社会已提升为国家战略。交通运输部为加快建设资源节约型、环境友好型交通,组织开展了“材料节约与循环利用专项行动计划”。通过专项行动大力推广路面再生技术、废胎胶粉筑路应用技术、机制砂混凝土技术以及聚合物改性水泥混凝土技术等西部交通建设科技项目成果,以为交通建设资源的高效利用和循环使用提供示范。本刊现以专栏形式介绍上述成果的相关内容,以飨读者。     

Modeling and analysis of mixed flow of cars and powered two wheelers

In modern cities, a rapid increase of motorcycles and other types of Powered Two-Wheelers (PTWs) is observed as an answer to long commuting in traffic jams and complex urban navigation. Such increasing penetration rate of PTWs creates mixed traffic flow conditions with unique characteristics that are not well understood at present. Our objective is to develop an analytical traffic flow model that reflects the mutual impacts of PTWs and Cars. Unlike cars, PTWs filter between cars, have unique dynamics, and do not respect lane discipline, therefore requiring a different modeling approach than traditional “Passenger Car Equivalent” or “Follow the Leader”. Instead, this work follows an approach that models the flow of PTWs similarly to a fluid in a porous medium, where PTWs “percolate” between cars depending on the gap between them.Our contributions are as follows: (I) a characterization of the distribution of the spacing between vehicles by the densities of PTWs and cars; (II) a definition of the equilibrium speed of each class as a function of the densities of PTWs and cars; (III) a mathematical analysis of the model’s properties (IV) an impact analysis of the gradual penetration of PTWs on cars and on heterogeneous traffic flow characteristics.The proposed model could contribute as an enabler for ‘PTW-aware’ future Cooperative Intelligent Transport Systems technologies and traffic regulations.     

油气管道的腐蚀与防护技术研究

国内大多数油田在开采过程中,油井伴生气通常含有成分不等的CO2、H2S等腐蚀性气体,同时由于油气集输系统也不可能完全密闭,造成大气中的O2等腐蚀性气体进入油气生产系统,因此油气生产系统存在的腐蚀类型多种多样。针对油气管道的腐蚀现状,简要综述了CO2腐蚀、H2S腐蚀、氧腐蚀机理及其影响因素。并在此基础上介绍了阴极保护技术、耐蚀材料防腐技术、工程防腐技术、化学防腐技术等几种国内外常用的防腐措施。     

高速公路改扩建工程水土保持监测与评价

开展水土流失监测是水土保持监管的重要手段。文章以广西沿海高速公路改扩建工程一期工程水土保持监测实践为例,分析了工程建设水土流失特点,介绍了水土保持监测技术和方法,并通过对工程实例监测结果的分析评价,提出了水土保持监测工作中易出现的问题及相应的解决方案。     

Characterisation of and reflections on the synergy of bicycles and public transport

The bicycle is often understood as a disjointed ‘feeder’ mode that provides access to public transport. We argue that combined use of the bicycle and public transport should be understood in a broader perspective, especially where bicycles link to higher speed and higher capacity public transport, such as the train. Cycling and public transport can have a symbiotic relationship forming a hybrid, distinct transport mode, which should be reflected in transport planning. The bicycle is as a way to soften the rigid nature of public transport and thus accommodate diverse individual travel needs and situations. Public transport can be seen as a means to dramatically extend cycling’s speed and spatial reach. We combine a system perspective with conceptual analysis to explore how, why and when this reconsideration is important. We use the Netherlands as illustrative case because of the relative maturity of its bicycle–train connections. The case shows that the synergy between rather opposite yet highly complementary aspects, high speed of the train, high accessibility of the bicycle and flexibility in combining both sub-modes, are the fundamental characteristics to understand the functioning of this system in a wider spatial context. In our conclusion we propose a research agenda, to further explore the relevance of this system for land-use and transport planning and distil wider implications for the international debate.     

公交支付方式及其效率调查分析

智能系统的广泛使用,带来了移动支付的普及。公交支付在传统IC卡和现金支付的基础上,加入了云闪付和二维码支付。为探究移动支付对公交支付效率的影响,基于杭州市公交发展现状,制定了公交支付情况的调查方案。通过对所选10、93、97公交线路的早、晚高峰和平峰的三天实地调查,采集视频数据并使用SPSS进行定量统计分析,发现公交乘客刷卡占62%、二维码占27%、云闪付占6%、现金占5%。当乘客提前做好准备时,刷卡支付时间为1.29 s,低于云闪付的1.42 s和二维码的1.65 s,而未准备好时用时分别为6.74 s、10.94 s、8.54 s。通过相关性和多元线性回归分析得出"提前拿卡"、"上车掏卡"、"提前开二维码"和"上车开二维码"四种支付方式对公交停留时间延长的影响最大。