New Approach for Documenting Historic Buildings
This paper discusses utilizing new 3D CAD system for documenting historical buildings. The 3D CAD modeling was used to generate three-dimensional drawings of the Main Justice Building Court yard. The courtyard, which covers approximately 4,500 square meters is situated over top of a parking garage in the Main Justice Building in Washington DC, and is comprised mainly of stonework. The scopes of the renovation work includes salvaging the courtyard stone, demolishing and rebuilding the concrete structure of the car parking below the courtyard, and reinstall the salvaged stone back in its original location. Traditionally, the measuring tape is used to document the vertical planes, and conventional surveying equipments are used to document the horizontal planes. In this project, the courtyard stone pieces are inherited in the building structure and some of the stones have unique threedimensional configurations that cannot be surveyed by conventional techniques. ValcunÆ 3D CAD modeling was used to document the locations and the shapes of the stonework in the courtyard before removing the stone and demolishing the concrete structure. 3D CAD modeling has the ability to locate the required points in the three- dimensional space. 3D CAD modeling was used to generate 2D and 3D CAD drawings for the courtyard. These drawings were used to re-fabricate the dismantled stones, and to reinstall the salvaged stones in their original locations. The field surveying of the courtyard was completed in 16 working hours. More than 3000 stone pieces were located in the three dimensional space to an accuracy range of 1/8" (Arch Second, 2000).