宁波市轨道交通管线详查方法

根据宁波市轨道交通建设过程中对管线详查的要求,介绍相应管线探测的主要技术方法,并成功解决深埋金属管线和深埋非封闭非金属管线的探测技术方法,同时优化了数据处理技术,提高数据查询效率。     

Accessibility tradeoffs in public transit planning

 Spatial accessibility is a critical consideration in the provision of services, both public and private. In public transit planning, accessibility is comprised of access and geographic coverage. Interestingly, these two considerations are somewhat at odds with each other. Access is important because it is the process associated with getting to and departing from the service. Such access is typically perceived of in spatial terms as the physical proximity to transit stops or stations. Additional stops along a route usually mean greater access, because a stop is more likely to be within an acceptable walking/driving standard for a larger number of people. On the other hand, more stops and greater access slow transit travel speeds, thereby decreasing the area of service reachable given a travel time budget. More stops along a route translate to greater service interruption and longer travel times. The faster the travel time, the more desirable the service. Further, if travel times become excessive, then user demand for service will decrease. All of this means that stop spacing along a route is central to accessibility, as it is a tradeoff of access (more stops) and geographic coverage (service efficiency through less stops). This paper details modeling approaches for addressing accessibility concerns in an integrated fashion. Bus-based transit service in Columbus, Ohio will be utilized to illustrate the usefulness of these approaches in transit planning. Received: September 2002 / Accepted: January 2003 This research was supported in part by an Ohio State University seed grant.     

Identifying transit corridors for elephant using a long time-series

The role of corridors in mitigating the effects of landscape fragmentation on biodiversity is controversial. Recent studies have highlighted the need for new approaches in corridor design using long-term datasets. We present a method to identify transit corridors for elephant at a population scale over a large area and an extended period of time using long-term aerial surveys. We investigated environmental and anthropogenic factors directly and indirectly related to the wet versus dry season distribution of elephant and its transit corridors. Four environmental variables predicted the presence of elephant at the landscape scale in both seasons: distance from permanent water, protected areas and settlements and vegetation structure. Path analysis revealed that altitude and monthly average NDVI, and distance from temporary water had a significant indirect effect on elephant distribution at local scale in dry and wet seasons respectively. Five transit corridors connecting Tarangire National Park and the northern as well as south-eastern wet season dispersal areas were identified and matched the wildlife migration routes described in the 1960s. The corridors are stable over the decades, providing landscape connectivity for elephant. Our approach yielded insights how advanced spatial analysis can be integrated with biological data available from long-term datasets to identify actual transit corridors and predictors of species distribution.     

Multiple transit times and least squares for gyroscopic azimuth

Principles of North determination using suspended gyrocompasses are reviewed. Accuracy is evaluated and a procedure with two series of measurements symmetrical with respect to the zero torsion tape position is mathematically proven to be the “best” (minimum variance). Our purpose is to prove that a 20″ accuracy (1 σ) instrument was brought to a level of accuracy four times better by using multiple transit times and least squares fit. Over a total of 15 North determinations based on more than a thousand transit times, an external standard error of 4″.4 was obtained using a WildGAK-1.     

广州市轨道交通首级精密控制网测量

根据广州市轨道交通2015年建设线路的布局要求以及技术难点,研究项目技术路线的制定以及GPS平面控制网和二等水准控制网的建设实施。项目充分利用一系列新技术手段,解决新旧控制网的整合协调以及精度一致性等技术难题,建设统一覆盖原有线路和新规划线路的精密控制网。     

利用GPS技术的货物运输车辆路径问题的遗传算法研究

提出了具有时间窗的货物运输车辆路径问题，根据车辆装载GPS设备的特性，建立了该问题的数学模型，并设计了求解它的遗传算法，初步计算表明算法具有很好的性能。     

经纬仪实时空间测量系统研制与应用

本文介绍了经纬仪实时空间测量系统的基本原理和系统配置,描述了系统的测量精度和误差影响情况,介绍了系统所具有的功能;通过对标准量具的检测,证明该系统是可靠的,对特种精密工程测量的精度要求是可以满足的,在其它领域也有广泛的应用前景。     

基于InSAR的城市地下轨道交通沉降与灾害监测

城市地铁建设会对邻域造成地质环境损伤,甚至发生灾变。传统基于点位测量的方法在实际应用过程中存在野外作业周期长、受天气影响及耗费大量人力物力等缺点。因此,本文基于城市地下轨道交通安全施工中的应用需求,以天津市地铁五号线为例,利用27景TerraSAR数据和PS-InSAR时序监测方法,对地下轨道交通地铁站和隧道施工影响进行了监测和评估。结果表明,PS-InSAR能在施工期间监测到地铁线及周边的形变,有利于城市轨道交通全生命健康监测。     

轨道交通隧道全断面病害智能诊断与服役状态评价

武汉大学和北京城建勘测设计研究院共同组建的城市智能感知与精密测量工程中心在深入研究地铁隧道结构监测现状的基础上,将移动三维激光测量技术应用于地铁隧道结构监测,提出一套适用于隧道结构和病害监测的硬件集成方案,研发了一套高效快速获取地下空间结构三维几何特征的方法,实现了隧道结构表观几何特征和病害监测成果高精度提取,并且获得了显著的社会效益和经济效益。本文通过轨道交通隧道全断面智能识别与分析系统的研发及检测装备的研发,实现了轨道交通全断面病害的智能检测与隧道服役状态的评价。     

新型测绘技术在轨道交通智慧建造中的应用

随着建筑业“十三五”规划收尾和“十四五”规划的启动,轨道交通智慧建造的水平大大提升。智慧建造能够辅助项目进行精细化智慧化管控,可以在一定程度上使得城市交通建设满足我国社会发展的现状和要求,但是在轨道交通智慧建造过程中出现的问题和需要考虑的因素较多。因此,本文在轨道交通智慧建造现有体系中引入新型测绘技术,分析其在应用中的主要特点和功能,重构了智慧建造架构体系,深入探讨了新型测绘技术带来的智慧变革,提升了轨道交通建设的整体水平和应用深度。     

Spectral analysis as applied to a set of gyrocompass transit times

Spectral analysis by least squares as developed by Vaníček is applied to a series of transit times measurements obtained with a suspended gyrocompass (Wild) electronically equipped with three photocells and a printing chronograph. Instead of being the Fourier transform of the autocovariance function as in the usual spectral analysis of time series (Wiener theory), the spectral function used here is a function of an estimator of the variance factor obtained after a least squares fitting of a sinusoid to the data. That function is normalized to values between zero and one. For step-by-step spectral analysis by least squares each time a significant frequency appears in the spectrum it is removed by least squares fitting of the corresponding sinusoid including a damping coefficient, the residuals being again examined by spectral analysis by least squares. We find four significant frequencies: the well known principal period of about 7^min in the spinning case; a very strong component with a period nearly exactly half the principal period and an amplitude of about 70″, explained by taking into account the second-order term in the theory developed by Jeudy, and two remaining periods with much smaller amplitudes (2″.9 and 0″.9). It is shown that the shortest period (0^s.021), predicted by theory, exists in the measurements and cannot be neglected. The smallest component is considered to correspond to the wobble which can easily be observed in the perturbed motion.     

城市轨道交通保护区综合安全管理研究与应用

随着城市轨道交通建设规模不断扩大,运营里程逐年累积,轨道交通沿线的工程建设项目存在数量多、工艺复杂、对在建/运营线路安全影响大等问题。本文分析了保护区内影响轨道交通安全的主要因素,针对轨道交通保护区安全管理现状提出综合解决方案,并设计研发出一套针对轨道交通运营安全管理的综合平台,在规范保护区内施工项目管理的基础上,运用物联网、三维激光扫描等先进手段,实现数据的快速采集、处理、分析及预警,保障城市轨道交通的安全运营。     

Optimizing GPS-guidance transit route for cable crane collision avoidance using artificial immune algorithm

GPS Solutions - A cable crane collision accident usually causes serious damage to workers, equipment and materials. Owing to the emergence of global position system (GPS), some new collision...     

轨道交通盾构隧道病害空间分布特征和自相关性研究

我国轨道交通已经进入新建与维护并重期。随着地铁隧道服役年限的增加,其病害种类不断增加,且各类病害呈逐渐加重的趋势。以三维激光测量隧道逐环监测数据为基础,研究隧道区间的病害空间分布特征和自相关性,全面掌握地铁隧道运营状态和病害发展趋势,是进行隧道病害防治的前提。本文利用某地地铁上行线隧道逐环三维激光测量数据,分析了错台、掉块、裂缝和渗漏水等病害在线路走向的空间分布特征,分析了病害与周边地质环境的关系。利用灰色关联分析算法研究了病害之间的相关性,为掌握隧道病害的发展趋势和认识病害之间的耦合关系建立了定量化的分析手段。本文为掌握隧道病害空间分布规律,预测隧道病害的发生、治理提供了有效依据,可以为地铁安全运营提供有力保障。     

Realizable accessibility: evaluating the reliability of public transit accessibility using high-resolution real-time data

Journal of Geographical Systems - The widespread availability of high spatial and temporal resolution public transit data is improving the measurement and analysis of public transit-based...     

城市轨道交通盾构隧道病害空间分布特征量化研究

随着地铁的不断建设与投入使用,我国正在逐步进入地铁运营养护期,地铁病害检测与运营养护也逐渐得到重视。随着地铁运营年限的增加,病害也呈现加重趋势。通过三维激光扫描技术获取隧道病害全面信息,利用空间自相关性分析地铁隧道病害的地理空间分布特征,对于认识病害形成机理,防治病害具有重要意义。本文以某地铁隧道通过三维激光扫描所获得的水平收敛数据为基础,利用空间自相关分析法定量分析了病害在地理空间上的分布特征,以及与周边水文地质环境的关系。结果表明,隧道病害在地理空间分布上呈现显著的空间正相关与空间集聚特性,且病害严重区与隧道周边水文地质环境密切相关。本文结果为隧道病害地理空间分布特征研究、认识病害分布规律及后期病害治理提供了有效依据。     

低空无人机的倾斜摄影测量技术在城市轨道交通建设中的应用

智慧地铁的建设需要三维模型的支撑,运用倾斜摄影测量技术,结合三维可视化技术,为智慧地铁提供了三维数据支撑,推动了全生命周期智慧地铁建设的全面发展。本文旨在以雄安新区城市轨道交通R1线为研究区,对其沿线85 km进行了无人机航飞工作,通过数据处理获取了沿线三维实景模型,并对模型成果精度进行了详细对比。结果表明,此次倾斜摄影测量成果满足1：500比例尺要求。此外,还对倾斜摄影测量技术在城市轨道交通建设中的相关应用进行了介绍,为城市轨道交通建设工作由二维向三维转变开拓了新的方向。     

基于公交大数据的满载率推算方法 ——以深圳市为例

城市可持续发展需要提升公共交通的供给能力。公汽满载率是公交规划、调度和服务评价等方面的重要参数。在公交信息化水平不断提升的背景下,由公交IC卡数据和公共汽车GPS数据等构成的公交大数据为获得相对精确的客流提供了可能。虽然已有相对稳定的OD推算方法,但对于公汽满载率的研究尚不够充分。本文提出基于历史公交大数据的大规模公交出行链搜素算法,在此基础上构建公共汽车满载率数据库,并以深圳市为例揭示了高满载率线路段的时空分布特征。本文研究对于揭示公汽服务整体水平和探测关键公交廊道具有较大价值。     

轨道交通沿线不同区段土地利用的差异性测度

为了研究轨道交通沿线的土地利用差异性变化,该文提出了一种面向城市总规用地、遥感影像数据探讨土地利用差异性的分析方法,为引导城市与轨道交通协同发展提供支撑,以合肥1号轨道交通为例,运用了ArcGIS空间和SPSS统计分析方法.研究表明,在时间维度方面:①用地的动态度、变化率和变化量大小排序均呈现出二环以外＞一二环之间＞一环以内.②在用地面积变化上,相交于二环以外,一环以外、一二环之间区域的用地面积变化不突出;空间维度方面:①轨道交通各站点周边用地均呈现多元复合型,而不同站点周边用地的主导功能有所差异.②各站点400～600m范围用地的信息熵和均衡度大小趋于较高值的平稳状态,200 m范围内信息熵和均衡度波动大.③各站点周边商业、居住和道路用地半径维数较高,道路、商业用地边界维数较高.     

Estimation of transit trip production using Factorial Kriging with External Drift: an aggregated data case study

Studies in transportation planning routinely use data in which location attributes are an important source of information. Thus, using spatial attributes in urban travel forecasting models seems reasonable. The main objective of this paper is to estimate transit trip production using Factorial Kriging with External Drift (FKED) through an aggregated data case study of Traffic Analysis Zones in São Paulo city, Brazil. The method consists of a sequential application of Principal Components Analysis (PCA) and Kriging with External Drift (KED). The traditional Linear Regression (LR) model was adopted with the aim of validating the proposed method. The results show that PCA summarizes and combines 23 socioeconomic variables using 4 components. The first component is introduced in KED, as secondary information, to estimate transit trip production by public transport in geographic coordinates where there is no prior knowledge of the values. Cross-validation for the FKED model presented high values of the correlation coefficient between estimated and observed values. Moreover, low error values were observed. The accuracy of the LR model was similar to FKED. However, the proposed method is able to map the transit trip production in several geographical coordinates of non-sampled values.