This presentation in part of the 2017 3D Digital Documentation Summit.
Reality Capture, 3D Modeling, and Historic Preservation: A Structural Engineer’s Perspective
3D modeling has been part of the preservation engineer’s toolbox for several decades. In the years since the technology’s inception, it has evolved from being an occasional (and expensive) novelty to an invaluable part of the engineering workflow. Two factors have driven this change. The first is the improvement in the equipment used for laser scanning. Scanners today are faster and more accurate than ever before. Laser scanning and photogrammetry have condensed days or weeks of data-gathering effort into hours.
The second evolution is in the software used to visualize the resulting data and to utilize it with structural analysis software. Point cloud data must be processed and analyzed before it can become truly useful information, and thanks to rapid advancements in 3D CAD, BIM, and structural analysis software, this is also faster and more accurate every day.
Our firm has successfully used point clouds and 3D models to:
· Access inaccessible spaces
· Map deformations in walls and floors
· Retrieve additional field measurements
· Investigate intricate structures
· Create quick and easy building visualizations
· Map multiple layers of building information into complex 3D structural models
· Identify areas of a building’s structural systems that need intervention (renovation, repair, replacement, reinforcement)
· Plan the course of Construction Phase activities based on the 3D information and modeling created during the Investigation, Analysis, and Design phases.
In order to have a successful point cloud workflow, of course, you must have effective communication between members of the project team—architects, engineers, contractors, and owners. Over our long history with laser scanning, we have honed our ability to identify important parameters for scanning criteria to meet the overlapping needs of architectural and structural point clouds. We have also seen
what kind of language is essential in writing contracts and requests for proposals to ensure that all parties have a clear understanding of the tasks at hand, and to ensure that the deliverables meet the stated requirements.
This presentation will cover lessons learned for various steps of a project, from working with surveyors to define accuracy & coverage requirements, through processing data into useful model information, to incorporating existing conditions into working documentation. Specific emphasis within our presentation will be how information and analysis results from 3D structural modeling have facilitated the maintenance and preservation of large amount of historic fabric. Our research efforts have included improving the integration of non-destructive testing (NDT) results, material testing, and electronic monitoring results into the overall 3D models that we’ve created. Our experience creating advanced and detailed structural models of existing buildings has pushed the envelope on such modeling for the past 20 years. Our most recent efforts have included collaboration with contractors, builders, and owners to help make the Construction Phase work proceed as smoothly as possible—utilizing 3D modeling.
Nathan Hicks joined Silman in 2009, and is an associate with the firm. In 2010, Nathan was awarded the Silman Fellowship, spending six months at the National Trust for Historic Preservation working with the Historic Sites Department. Prior to Silman he received a BS in Architectural Engineering and MS in Architecture from California Polytechnic State University. Nathan is a member of APT DC, National Trust for Historic Preservation, and the DC Preservation League. Since joining Silman he has worked on the St. Elizabeth’s West Campus in DC, Washington Union Station, Mount Vernon and the Lincoln Memorial; among other projects.
Kate Morrical joined Silman’s DC office as an engineer and CAD specialist in 2003. She worked on new projects and renovations, contributing both to the engineering design and construction documents. After working for several years with Autodesk, where she worked closely with the AutoCAD and Revit teams, Kate returned to Silman as the firm’s Digital Design Manager. She is tasked with developing an integrated approach to modeling, design, and documentation across multiple software platforms. Kate is involved with every level of BIM at Silman, including in-house training and technical support, production of construction documents, and internal and external model coordination.