斜拉桥换索施工监控方法

通过分析涪陵长江大桥的工程现状,确定了该桥换索施工监控的内容,从主梁应力监控、斜拉索索力监控、主梁线形监控、主塔偏位监控四方面阐述了换索施工监控方法,并总结了一些施工技术要点,以供参考。     

A synchronous distributed cloud-based virtual reality meeting system for architectural and urban design

In the spatial design fields such as architectural design and urban design, a consensus-building process among a variety of stakeholders like project executors, architects, residents, users, and general citizens is required. New technological developments such as cloud computing and Virtual Design Studios (VDS) enable the creation of virtual meeting systems. This paper proposes an approach towards a synchronous distributed design meeting system. In this paper, in addition to sharing a 3D virtual space for a synchronous distributed type design meeting, we developed a prototype system that enables participants to sketch or make annotations and have discussions as well as add viewpoints to them. We applied these functions to evaluate an architectural design and urban landscape examination. In conclusion, the proposed method was evaluated as being effective and feasible. Yet, it shows a few shortcomings including the fact that simultaneous operation is limited to one client, and more arbitrary shapes should be supported in future versions of the application.     

桥梁健康监测中的传感器选型与设计

结合桥梁健康监测的发展,简要评述了一些传统和新型传感器的性状功能,并对传感器的选型原则与设计要点进行了初步探讨,指出除满足一般技术特性要求外,更多的要考虑到系统的功能性、鲁棒性、相容性及扩展性要求。     

预应力混凝土连续刚构桥应力监测分析

以增江大桥主桥施工监控为依托,阐述了应力监控对进行安全施工的重要性,根据施工过程中实测的控制截面应力数据,分析了振弦应力测试误差的主要来源,提出减少误差的方法,对应力实测值与桥梁结构分析程序Dr.Bridge计算的理论值进行了对比,指导了施工,确保了质量。     

某大跨连续刚构桥箱梁施工应力监测

本文介绍某大跨度连续刚构桥施工阶段的应力监测,通过对箱梁悬臂施工直至全桥合拢的应力监测数据与有限元计算结果比较分析,得到一些有意义结论。     

光纤光栅传感器在城轨桥梁监测中的设计与应用

针对城轨桥梁运输特点,确立了桥梁在线健康监测系统的监测内容,根据识别误差最小等准则进行了传感器优化布置,将该监测系统示范应用到了两跨简支梁桥梁,结果表明,该系统能反映桥梁长周期实时运行情况,适用于桥梁变形趋势的研究和桥梁健康评估。     

连续箱梁桥预应力加固施工监测及分析

通过在施工中安装锚索计测量预应力束的有效预应力的方法,进行了体内预应力及体外预应力张拉效果的影响因素方面的研究,提出了关于预应力加固施工的建议,以期指导实践。     

混凝土拱桥施工监测仿真技术研究

采用通用有限元软件ANSYS 8.0,对大跨度钢筋混凝土拱桥全桥结构按设计荷载进行了全桥静力分析,得出各主要结构构件的应力、内力和变形值,从而找出了各构件监控的主要部分,从而为拱桥施工监测仿真技术研究积累经验。     

南昌新八一大桥健康监测预警指标计算分析

为了保证桥梁健康监测系统的有效性和及时性,给桥梁管理者提供维修及加固的依据,以南昌市新八一大桥为工程背景,在有限元数值模拟结合传感器监测数据的基础上,建立了多指标并行预警的结构预警体系,阐述了预警指标、预警阈值和预警流程,并重点对索力、关键部位应力和挠度、疲劳车辆荷载、固有频率变化率等预警指标进行了计算分析。应用结果表明,在当前荷载作用下新八一大桥的各项预警指标的结果都正常,满足使用要求。     

Continuous dynamic monitoring of a centenary iron bridge for structural modification assessment

A multi-channel continuous dynamic monitoring system has been installed in a centenary iron arch bridge on late November 2011. The historic infrastructure, completed in 1889 and crossing the Adda river about 50 km far from Milan, is the most important monument of XIX century iron architecture in Italy and is still used as roadway and railway bridge. The monitoring project follows a series of preliminary ambient vibration tests carried out on the bridge since June 2009. The paper describes the bridge structure and its dynamic characteristics identified from the experimental studies developed since 2009, the installed monitoring system and the software developed in LabVIEW for automatically processing the collected data. Subsequently, the tracking of automatically identified natural frequencies over a period of about 18 months is presented and discussed, highlighting the effects of environmental and operational conditions on the bridge dynamic characteristics as well as the detection of structural changes, mainly based on natural frequencies shifts.     

浅析疏港航道工程204国道桥主桥施工监控

主要从该桥主梁施工过程监控工作的组织形式和主要监控工作内容等方面进行了论述，并对施工过程中监测的应力、变形数据进行了整理和简单分析，为类似桥梁开展施工监控工作提供参考。     

滑坡监测多源系统云服务平台架构及工程应用

 随着计算机科学和网络技术的快速发展,大量地质灾害监测系统应运而生,取得了丰富的研究成果,但也暴露出许多瓶颈问题,如预警阈值确定困难、传统服务器受硬件限制可靠性差等。针对上述问题,首先采用多源信息融合技术,将云服务器(ECS)、云数据库(RDS)和云网站等数据安全储备系统嵌入到“牛顿力变化监测预警系统”中;然后,采用数理统计方法,根据灾变信息监测预警需求,建立长期、短期和临滑预警模式及阈值,并开发出灾变信息发布APP终端、微信公众平台和监测点GIS自动搜索系统,集多源信息发布和搜索技术于一体;最后,利用该系统提前45 d对南芬露天铁矿“2016–1101滑坡”进行长期预报,提前30 d进行中期预报,提前4 h在全矿范围内发出灾变临滑预警,避免了大量人员伤亡及财产损失,证明该系统具有信息发布及时、平台丰富、发布面广等特点,能够适应复杂环境下滑坡灾变监测预警需求。     

Development of performance assessment tools for a highway bridge resulting from controlled progressive monitoring

As highway bridges continue to deteriorate given the increased service life, increase in vehicle demand and exposure to harsh environmental climates, new methods of monitoring their in situ performance are of high priority. Damage within the structure can alter various load demand and capacity characteristics, affecting the overall integrity of the bridge. Discussed in this paper is the monitoring of a simple span bridge superstructure under various induced damage states. Strain measurements were recorded at the midspan and north abutment of each girder. Six levels of damage progression were implemented at a rocker bearing and various diaphragms to girder connections. Transverse load distribution factors (DFs) and neutral axis (NA) locations were measured for each damage case and evaluated against the baseline undamaged response. These measurements serve to provide a possible method of damage detection using load-testing parameters already employed by various transportation agencies. Next, a performance index (PI) is developed for this stringer/multi-girder bridge utilising the NA and DF response from the steel girder system and the allowable stress design load-rating data. The ratio of NA to DF was compared to the inventory load rating for each girder at each damaged state. The data were fitted with a power regression model to form the PI. Furthermore, a 95% prediction interval was used around the predicted response to capture all the data from the testing. The model was applied to the damaged structure as well as two additional stringer/multi-girder bridges. The objective of the PI is to complement existing qualitative assessment protocols with quantitative results for improving the condition assessment process.     

大型桥梁结构智能健康监测系统集成技术研究

首先分析研究了桥梁健康监测系统的各个子系统的功能、特点、实现方法与硬软件系统,研究了完成桥梁健康监测任务对各个子系统协同工作的要求。提出了以LabW indows/LabVIEW为桥梁健康监测系统的核心软件,由它“指挥”、调用和驱动各个子系统的运行和数据的交互与通讯;以数据管理子系统的数据库作为桥梁健康监测系统的中心数据库,它不仅存储桥梁结构及其监测数据的全部信息,同时所有的数据交互均通过该数据库完成。建议采用B rower/Server系统模式将桥梁结构健康监测的各子系统相互结合,建立基于网络平台的开放式的实时在线智能健康监测系统。最后,为一座实际的三塔斜拉桥集成了一套健康监测系统。     

Frontier of continuous structural health monitoring system for short & medium span bridges and condition assessment

It is becoming an important social problem to make maintenance and rehabilitation of existing short and medium span(10-20 m) bridges because there are a huge amount of short and medium span bridges in service in the world. The kernel of such bridge management is to develop a method of safety(condition) assessment on items which include remaining life and load carrying capacity. Bridge health monitoring using information technology and sensors is capable of providing more accurate knowledge of bridge performance than traditional strategies. The aim of this paper is to introduce a state-of-the-art on not only a rational bridge health monitoring system incorporating with the information and communication technologies for lifetime management of existing short and medium span bridges but also a continuous data collecting system designed for bridge health monitoring of mainly short and medium span bridges. In this paper, although there are some useful monitoring methods for short and medium span bridges based on the qualitative or quantitative information, mainly two advanced structural health monitoring systems are described to review and analyse the potential of utilizing the long term health monitoring in safety assessment and management issues for short and medium span bridge. The first is a special designed mobile in-situ loading device(vehicle) for short and medium span road bridges to assess the structural safety(performance) and derive optimal strategies for maintenance using reliability based method. The second is a long term health monitoring method by using the public buses as part of a public transit system (called bus monitoring system) to be applied mainly to short and medium span bridges, along with safety indices, namely, “characteristic deflection” which is relatively free from the influence of dynamic disturbances due to such factors as the roughness of the road surface, and a structural anomaly parameter.     

Unified Frontiers: Reaching Out with BIM

Coren Sharples is a partner of SHoP Architects in New York where building information modelling (BIM) has become integral to the fluid promotion of communication between contractors, consultants and clients on a project. This is exemplified by two projects in the city: the reconstruction of Rector Bridge, where BIM enabled SHoP to work seamlessly with a firm of custom boat builders and other contractors, and the speculative development at 290 Mulberry Street, where it became a significant means of disseminating key data to the client for marketing and financial planning. Copyright © 2009 John Wiley & Sons, Ltd.