Bridging the continental divide: monitoring construction of a landmark bridge in Turkey

作者：Özgür Avci &T/F/D

完成后，1915年çanakkale桥在土耳其将最长的中跨悬架bridge in the world. At just over 4.6 km, it will span the Çanakkale Strait and complete a new southerly motorway route between Turkey and the rest of the European continent. Four partner companies are working on the complex build as a joint venture, Limak and Yapı Merkezi from Turkey, Daelim and SK E&C from South Korea (DLSY JV). The partners contribute global technical expertise and experience to each phase of the project, started in 2017. Kwangsoon Hwang is the Survey Manager at DLSY JV, overseeing the survey aspects of the construction and monitoring geometry control. During the tower building phase, Hwang’s challenge was to gather reliable data on the real-time positioning and long-term monitoring of the pylon towers. Using Leica Geosystems equipment, installed byLeica’s distribution partner SISTEM A.S.，Hwang和他的团队以最高的精度按时完成了调查工作。最初的施工后，设备将作为桥梁的永久监控系统。

A bridge of national and international significance

这1915年çanakkale桥and Malkara-Çanakkale Motorway Project is a mega-scale investment in transportation and infrastructure set to make a significant contribution to Turkey’s economy. This new route will take the pressure off the current motorway link, which travels through Istanbul. It will make commercial and tourist travel easier, bringing Turkey closer to Europe and the Balkans. As well as its substantial commercial importance, the symbolic importance of the bridge is honoured by some of its design elements. The 2,023 metres-long mid-span between the tower legs of the bridge symbolises the 100th year of the foundation of the Turkish Republic. In contrast, the tower height of 318 meters above sea level symbolises the 18th of March 1915 Çanakkale Victory, one of the most important dates in the history of Turkey’s struggle for independence.

准确的定位数据对于构建塔至关重要

Accurate positioning of the caissons (watertight retaining structures used in the towers’ foundations) and the towers themselves are critical in the construction of the bridge. The sections of the towers are manufactured off-site, and the design tolerances are exceptionally tight so fractions of a millimetre matter in piecing the structure together. To monitor the real-time positioning of the fabricated blocks during the build, Hwang and his team used 16Leica GM30 GNSS receivers for monitoringwith 16Leica AS10 GNSS Compact GNSS Antennas，每个塔上的四个。

每个塔由两座塔组成。Leica GNSS蜘蛛软件was used to calculate the positions of each receiver, employing three units ofLeica GR30 reference serverswith threeLeica AR10 GNSS Antennas。Hwang解释说，他们从Spider软件的实时，15分钟，30分钟，一小时和两个小时的基线处理中收到了数据。这Leica GeoMoS monitoring softwarecalculates the average position of baselines which are calculated from three references. The data collected was used for geometry control of the Towers in order to install the towers within specified tolerances.” The Leica Geosystems monitoring solution provides easy access to all available data from all GNSS units in one convenient location, helping the users in the field and their colleagues in the office to be most efficient. Real-time positions were used by the Bridge Fabrication teams to monitor the positions and verticality of the towers, making sure that they were safely and accurately slotted into place.

关于天气状况的定期报告在悬架桥建造中至关重要

In addition to the positioning data, wind speed and direction data, as well as temperature sensor data, were assimilated by the Leica GeoMoS software. Up-to-date graphics and regular reports were quickly generated by theGeoMoS Now! monitoring web-service,saving time for Hwang’s team: “The possibility to combine all data collected on site in real-time and display the accurate results in GeoMoS Now! speeded up our processes at the office and the operations on site.” Leica GeoMoS Now! is a web-based application that provides round the clock access to monitoring project data via any web-based device. Dashboards can be customised to provide easy-to-read reports for different users and job functions, for example, engineers or fabrication teams. Being able to give instant access to data allows for early detection – and resolution – of any problems.

Easy to use system saved time on data collection, processing and training

经过准确的态度，解决方案的主要好处及其团队的能力可以节省时间和更快的速度。这包括培训，这是一个快速的过程，因为Leica Geosystems设备可直接使用。Hwang解释说：“我们需要培训所有将使用此解决方案的人员。借助Leica的授权经销商Sistem A.S.提供的手册和培训，几乎没有时间轻松适应解决方案。在项目期间，他们还提供了与建筑工地中任何问题有关的24/7全天候和远程支持。”

Ongoing monitoring to keep bridge passengers safe

“由于塔楼已经完成，因此该产品将用于电缆安装，并且在项目完整完成后，它将用作整个桥梁的永久监控系统，” Hwang解释说。Leica GNSS蜘蛛被配置为以后处理模式计算基线，并且在Geomos数据库中存档了高准确的结果，从生成周期性报告。Leica GM30 GNSS监控接收器以及Leica AS10 GNSS天线设计用于低能消耗低的连续操作，并且足以挑战天气条件 - 非常适合在高空的桥梁，暴露于元素上。由于在大型和敏感的结构上安装很困难且昂贵，因此它们也通过超出当今所需的信号需求而设计为未来。当1915çanakkale桥和Malkara-cousanakkale高速公路于2022/2023完成时，他们仍将到位，并在未来多年观看通勤者和旅行者。

For more information contact the monitoring solutions specialists at Leica Geosystems.