Digital monitoring of major urban construction sites

With more than 300,000 inhabitants, 160,000 vehicles in the main part of the city and 190 million tram passengers every year, Karlsruhe plays a decisive role in transport planning in Southwest Germany. Not only does the highway A5 influence the planning scenarios in the greater Karlsruhe area, but also the inner-city use of the state street B10. This is the most important inner-city east-west connection for the region. The City of Karlsruhe as well as the Federal State of Baden-Wuerttemberg react on the development of the traffic and the whole region by launching two exceptional tunneling projects for the relief of ground traffic with the project "The Combined Solution."

诸如“组合解决方案”之类的项目不仅没有支持者。建筑噪音，日常生活的破坏，成本，污染和环境限制只是在从事此类大规模城市项目时必须考虑的潜在问题的一部分。Karlsruhe市和Karlsruhe铁路基础设施协会（Kasig）作为建筑商为此目的开展了长期且非常早的信息运动。这是以项目网站的形式进行的，还通过公共活动和信息中心进行。建筑商以及参与的建筑公司和财团的目的也充分利用了数字解决方案在建筑工地文档中的可能性。Leica Geosystems的测量解决方案由KarlsruheIngenieurbüroGeo GmbH使用是该数字文档的决定性因素。

Highest accuracy from day one

建筑公司埃德。Zublin Schleithare responsible for the construction of the Kriegsstrassentunnel next to the Ettlinger Tor. Combined with the second tunnel in Kaiserstrasse, both construction projects are "The Combined Solution" for the City of Karlsruhe, which will help to significantly alter the traffic situation in the inner city from 2020 and 2021 respectively. In the Kriegsstrasse, this means that the vehicles are brought under the earth, while trams, pedestrians and all bicycles move above ground. On a path of 1,600 meters, the road tunnel dramatically changes the cityscape - as well as during the construction work. The construction planning and subsequent construction supervision is also given special importance for this reason. The objective of the construction supervision cooperation, consisting of DB Engineering & Consulting, Emch+Berger and BUNG, is to get the highest accuracy in surveying, preservation of evidence and monitoring. Before working on new construction sections, the task was the initial surveying of the construction area as well as an area of 50 meters in all side streets. The expected accuracy of the data was 2 cm. This task was taken over by the team of IngenieurTeam GEO, using the Leica Geosystems Unmanned Aerial Vehicle (UAV). Equipped with the RTK and GNSS module, this technology allows airborne data to be collected parallel to the on-site operation, delivering highly accurate data by combining the UAV and the Sony Alpha 6000 with a 20mm lens.

A special challenge when flying in the city centre

围绕该项目，联邦法院和卡尔斯鲁厄州立剧院是关键建筑。正如隧道建筑工地的习惯一样，必须确保该构建不会导致环境计划外的变化。任何减少或不需要的变化都必须排除在外。该排除必须进行记录和监控。出于安全和时间原因，传统方法只能在有限的范围内与施工措施并行使用。然后，将无人机的使用视为以面向效率的项目过程的意义进行数据捕获的最佳解决方案。与使用陆地方法的纯粹基于点的数据采集相比，3D测量和监视的优点特别在于生成数据的各种用法方案。他们不仅可以从测量工程师的角度回答问题，还可以用作施工工作期间交通路线的规划的基础。它们可以用于亲和回顾性的施工计划，并且几乎是实时计算的决定性因素。

The advantages of using UAV are on the one hand side, the challenges of flying in the city center are on the other hand side. Thus the narrowness of the city has to be taken into account already in the planning of the automated flight and therefore the flight route and altitude planning has to be defined specifically. Potential disturbances of the flight by cranes, vegetation and possible magnetic field disturbances due to the existing infrastructure and development play a role. Benjamin Busse, an experienced expert in the field of the use of surveying drones at IngenieurTeam GEO, has therefore placed special emphasis on the involvement of all stakeholders during the planning phase.

“新无人机在德国不允许规定flights over federal streets,”says Busse. “Thanks to a good relationship with all stakeholders we got the special permission for the inner-city flights over the B10 with traffic, pedestrians and tram.”

使用无人机的优点一方面是在市中心飞行的挑战。因此，必须考虑到自动化飞行的规划，因此必须考虑到城市的狭窄，因此必须专门定义飞行路线和高度规划。由于现有的基础设施和开发而导致的起重机，植被和可能的磁场干扰对飞行的潜在干扰起作用。因此，本杰明·布斯（Benjamin Busse）是在Ingenieurteam Geo使用测量无人机领域的经验丰富的专家，因此在计划阶段特别强调了所有利益相关者的参与。

“新无人机在德国不允许规定flights over federal streets,” says Busse. “Thanks to a good relationship with all stakeholders, we got the special permission for the inner-city flights over the B10 with traffic, pedestrians and tram.”

Digital results and economic benefits

Apart from classical orthophotos, the customers also expected high-resolution single images for documentation, digital elevation models and point clouds. At the same time, the inspection of traffic route planning was mandated. This took place on the basis of existing plans, which were combined with the information from the orthophotos. As a result of the very good data from the flights and the high information quality, it is now planned to carry out quarterly monitoring, critical volume calculations as well as a supplement to the construction site diary through videos and photos from the bird's perspective with the help of UAV solutions.

The reasons for this decision are summarised quickly: using conventional measurement and surveying methods, not only significantly less data could be collected, a team of five people would have needed six weeks to deliver the desired results. The team of two people for the UAV workflow, only needed seven days. Conventionally, Leica Geosystems total stations would be used. The costs for the client using the conventional method would have been 180 per cent higher than working with the UAV solution. The monetary perspective is even more attractive from the UAV operator’s point of view: the costs for IngenieurTeam GEO using the UAV solution were only one-fifth of the costs of conventional methods.

“我们认为无人机技术是我们工具箱的一部分,” adds Martin Schwall, co-founder and managing director with IngenieurTeam GEO. “From a customer’s point of view, UAVs allow fast and digital results with many advantages for additional information.”

Digital workflows offer many advantages

The use of the UAV solution from Leica Geosystems offers a multitude of advantages. The digitisation of the processes associated with construction projects always depends on a high data quality and density. For example, the information from the UAV flights can be used not only for planning and monitoring, but also for machine control and project communication tasks. In a further development step, the data of the UAV will also be seamlessly integrated into the software solutions of Leica Geosystems. The results are not only faster but can be customised to meet individual requirements with little effort. While conventional methods generate selective data, they do not capture image data, and therefore do not allow digital visualization. The use of a digital end-to-end solution based on UAV, corresponding sensor technology (here high-resolution RGB camera) and suitable software for postprocessing and data processing offer real benefits. Apart from images, this is mainly 3D measurement information, the option of a parallel inspection based on the image data, the data capturing parallel to the day-to-day business as well as a much higher safety for the locally working surveying engineers and UAV operators. The generated data is the basis for answering existing and future questions and will help to archive all construction progresses from the first day.

“As a next step, Leica Geosystems will fully integrate the UAV solutions in the software solutions for construction, monitoring and surveying”, says Valentin Fuchs, Leica Geosystems UAV product manager. “Helping our customers to visualise information and to use the collected UAV data to automate and speed-up processes is part of the bigger picture of future developments.”