Hamburger Hafen und Logistik AG (HHLA) manages all sorts of structures for the city of Hamburg. Their responsibility includes the historical Speicherstadt but also parts of the port. Many of those structures are build on pillars which are directly grounded into the river bottom and are partially under water and therefore hard to reach. For a long time, HHLA searched an easy and safe method to inspect the condition of those pillars.
Pile structures are challenging to inspect even with the latest survey technology. VRT has a long experience in surveying all kinds of port structures, so the field crew has knowledge about how these tricky objects can be inspected effectively.
Sonar scanners can’t “see” behind corners, which means that mobile surveying of pile structures needs to be done so that the beam of sonar scanner reaches the surface from as many different angles as possible. This may require multiple surveying lines from different directions. Not all of the pile’s backside can be surveyed, but a talented surveyor can capture a good overall impression of the complex structure. This is usually sufficient to evaluate the general state of the structure and enough to find damages.
The survey area included a suspended quay under one warehouse. The field work was done within one working day, and the office team of VRT post-processed the survey data, cleaned and analysed it. The 3D data with the observations of a licensed marine inspector was delivered via an online platform GISGRO, where HHLA and its engineering consultants could access and analyse the results easily.
GISGRO is a handy way for delivering 3D data, which normally is quite tricky to access without suitable software and knowhow. Via an online platform, the data is also easy to share with all the stakeholders. Maintenance or construction planning is easier, when it is possible for the project managers to see the structures even below water with your own eyes.
The real estate department of the Hamburger Hafen and Logistics AG was very satisfied with the execution and results of the sonar survey. A similar survey with traditional methods, e.g. by divers would have been much more complex and therefore time consuming. Furthermore, the documentation result is much more precise and richer in details.