基于无损检测的输油管道环焊缝缺陷安全评估

输油管道环焊缝开裂可能造成严重的威胁,但漏磁内检测技术难以精确识别及量化环焊缝缺陷。因此,基于漏磁内检测数据结果的适用性评价结果可能存在较大的偏差。为此,对比环焊缝缺陷无损检测结果,分析漏磁内检测环焊缝缺陷的尺寸量化精度,并基于无损检测的缺陷尺寸进行失效评估,结合管道实际运行压力,进行疲劳强度校核。评估结果显示无损检测识别的环焊缝缺陷均满足安全评定要求,不需要修复。     

输油管道环焊缝缺陷疲劳寿命评估

采用管道失效评估方法可评估静载荷作用下缺陷是否满足适用要求。但在内压等交变载荷作用下,输油管道环焊缝仍存在疲劳破坏的可能。为评估管道环焊缝缺陷的疲劳寿命,进行管道母材和环焊缝疲劳裂纹扩展速率试验,并分析和统计管道实际运行压力数据以及环焊缝缺陷开挖验证数据,采用BS7910标准方法计算疲劳寿命值。结果显示在仅考虑管道内压波动情况下,管道环焊缝平面型缺陷的疲劳寿命结果满足管道设计使用要求。     

在役压力容器管座角焊缝的相控阵超声检测

为了提高在役压力容器管座角焊缝缺陷的检测效率以及缺陷检测的可靠性,文中对在役压力容器管座角焊缝相控阵超声检测方案进行验证。调整了用于在役压力容器管座角焊缝检测的扫查装置,确定了实验方案中实际缺陷长度的计算方法。通过相控阵超声检测扫描获得的图谱,可以对管座角焊缝的典型缺陷进行识别和评定。该研究同时可协助解决管座角焊缝不同类型缺陷的定性分析和定位难题,对管座角焊缝相控阵超声检测图像识别和结果评定有借鉴作用。     

长输管道环焊缝的射线数字成像检测技术应用

文中分析了长输油气射线数字成像检测的3种技术类型,及其在油气管道环焊缝检测方面的优缺点和发展趋势。开展了在役输油管道动火作业中射线数字成像检测技术(DR)的现场应用试验,初步验证了在役管道环焊缝DR检测的技术可行性和对缺陷检测的较高灵敏度。结合中俄东线输气管道建设,进行了传统射线胶片照相检测技术(RT)和DR检测技术工程应用效果的对比试验,试验结果表明现阶段RT检测胶片数字化技术能够较好地解决存量胶片检测影像资料的数字化存储和管理,而DR技术在缺陷检测数字成像方面呈现出较高的对比度,但目前DR检测效果不稳定。DR检测技术在长输管道工程的大规模应用推广,需进一步完善DR设备校验等方面的技术管理体系。     

地面标记系统在管道漏磁检测缺陷定位中的应用

为提高埋地管道漏磁检测缺陷基于地面标记系统地面定位的准确性,根据不同漏磁检测数据在相应管线上进行开挖验证及开挖修复项目中缺陷地面定位实践,简述了漏磁检测缺陷点地面标记系统及地面定位原理,分析了地面定位误差来源及可能的偏差方向,总结了实践中不同情形下漏磁检测缺陷点准确定位方法及参考环焊缝确认方法。实践表明,地面定位技术利用MARK点定位管道特征点,从而定位缺陷;管道某些特征点是精确的参考点;开挖时根据现场条件推断误差来源及可能偏差方向;参考环焊缝利用开挖测量法或轴距测算法确认。     

定标点失效对中心线坐标及应变数据的影响分析

为了研究定标点失效对管道中心线坐标及应变数据的影响，文中以管道环焊缝作为特征点对比2次中心线检测的环焊缝球面距离和管道应变数据，研究定标点失效情况下数据偏差情况。结果表明：对于1 km/点设置定标点时，环焊缝位置的偏差能保持在2 m范围内，对于1～2个定标点失效时环焊缝偏差会扩大到5 m,对于连续5点定标点失效时，环焊缝位置的偏差会超过14 m,该坐标数据已失效；对于极限情况连续5个定标点失效的情况下，通过环焊缝仍然可以将2次检测应变数据进行对齐，且检测数据能够良好复核，对于连续5个定标点失效情况下应变数据仍准确有效。     

管道环焊缝X射线数字成像动态采集软件设计

目前,国内的管道环焊缝数字射线检测设备仅能实现静态成像,曝光时间过长,成像结果由多张图像组成,增加了判读工作量和图像评定难度。管道环焊缝X射线数字成像动态采集系统解决了这些问题,采集面板在电机的驱动下沿着轨道匀速行驶,采集图像无缝无重叠地连续实时显示,最终形成一幅完整的管道焊缝扫查图。针对数字射线动态数据采集系统的TDI原理、TDI扫查的时钟同步源、CMOS平板探测器中偏置电压的刷新和面板校准等问题进行详细说明,完成了X射线数字成像动态采集软件的设计和编程,并在管径813 mm、壁厚12.5 mm的管道环焊缝上进行检测试验,采集图像中缺陷清晰可见。     

管道环焊缝数字射线检测软件设计

X射线平板探测器数字成像是一项现代射线检测技术。由于X射线探测器的图像质量和包含的信息远远超过普通胶片成像,该技术代表了射线检测技术的发展方向。基于平板探测器的管道环焊缝数字射线成像系统的特点,对降低图像质量因素进行仔细研究,对随机噪声、像元响应不一致等降低图像质量因素进行了有效的抑制,完成了管道环焊缝数字射线检测软件的设计和编程,实现了检测图像的动态拼接和管道环焊缝数字射线检测系统的现场应用。     

管道环焊缝数字射线检测技术研究

在管道环焊缝检测技术领域,X射线检测技术和超声检测技术并存可以取长补短。随着数字化X射线成像技术的推广应用,管道环焊缝X射线检测正向数字射线技术方向发展。由于射线探测器的图像质量和包含的信息远远超过普通胶片成像,数字射线技术代表了管道环焊缝检测的发展方向。管道科学研究院通过对面阵探测器成像技术的研究,开发出了管道环焊缝数字射线成像设备,实现了管道环焊缝射线检测的实时显示和电子存储。     

长输油气钢质管道维修搭接焊缝超声探伤

为实现输油气管道搭接焊缝内部缺陷的全面检测,进一步采取整治措施、消除安全隐患提供有效依据和数据支持,保证管道安全运行,文中将超声脉冲回波法与透射传输法相结合,提出一种多通道在役管道搭接焊缝检测新方法。为了验证该方法的可行性,针对焊缝可能出现的焊接缺陷制作了一系列试块并进行了试验验证,试验结果表明该方法能够准确发现焊缝内部裂纹、未熔合、未焊透、夹渣和气孔等缺陷,为管道的安全运行提供技术保障。     

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。     

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.     

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.     

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。     

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。     

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。