Laser scanning technology helps preserve and repurpose a historic masonry building in Crete
Postgraduate students at the Technical University of Crete used a combination of a Trimble Laser Scanner, PointCab Origins Pro, and Autocad to obtain and document the exact geometry of a historic masonry structure with the purpose of its structural rehabilitation.
The island of Crete, Greece is known for its beautiful landscape and rich history. It’s the birthplace of the first European advanced civilization, the Minoans, and was shaped by the Mycenaeans, Romans, Osmans, and many more. The traces of these cultures can still be found all across the island in different archeological remains.
One of them is a two-century-old residential masonry, built during the Osman rule. It has been abandoned for the last 70 years and is the former residence of the wealthy Seimeni family. As one of the few remaining buildings of that type of local architecture in the region, it bears great historic value. In order to preserve and repurpose the building, exact documentation of its geometry was required, among other factors, in order to assess its structural integrity and the degree of necessary strengthening interventions. The building is planned to be restored in the next years and to be used as a local folk art museum.
Postgraduate student Eirini Chorianopoulou, supervised by Professors Maria Stavroulaki and Nikos Skoutelis decided to exploit the benefits of the latest laser scanning technology available. Since there were parts of the building that could not be approached and a distant measurement technique was needed, using simpler tools and techniques would not suffice. Therefore, an accurate digital representation of the building in its condition before the restoration could be captured.
This will give future visitors the chance to understand and compare the prior and current state and appreciate the work that will be done in order to preserve the authenticity of the structure after its restoration. With the purpose to obtain the geometric properties of the structure, the Trimble X7 3D laser scanner was employed. A number of 25 scans were used to generate the point cloud. All the data was imported as e57 format files and edited in PointCab Origins Pro. Accurate plans, sections, and elevations of the structure were created at all necessary levels and were exported as .dwg files for further editing in Autocad.
Postgraduate researcher Evangelos Nitadorakis, responsible for handling the point cloud evaluation, found himself satisfied with the results that the use of PointCab’s Origins software provided: “The accuracy of the generated sections allowed the identification and quantification of pathology indicators such as wall inclinations not visible with the human eye and remote measurements in parts of the structure that are not easily accessible. In addition, the delta analysis tool helped to distinguish even the slightest deviations in vertical levels. Furthermore, with a proper combination of all the data from Origins, an exact 3D model of the structure was created in a FEM analysis software and structural and dynamic analysis were conducted in order to assess the fragility of the structure under various loading cases. Employing PointCab Origins, we appreciated the easy handling, the speed of data processing, and the quality of the outcomes.”
