JPL - Building 280
Pasadena, CA
SF 1,500
Client
NASA - JPL
Services
Building Documentation - Laser scanning and 3D modeling
PARTNERS
Architectural Resource Consultants
When the engineering team at NASA’s Jet Propulsion Laboratory was preparing to perform some tests using a 51 ft static tower, it needed to run a structural analysis to determine if the tower could withstand loads higher than anything that had been tested before. Unfortunately, the record drawings available at the time contained insufficient information, and so the analysis required an up-to-date, as-built model for the static tower.
As the building documentation professionals, ARC partnered with RC Monkeys to develop the much-needed deliverables.
The first step in producing the as-built model involved carefully planning the laser scanning phase, which was critical for ensuring the specified measured and represented levels of accuracy, as well as the level of detail. After testing various instruments, we decided to utilize the Leica RTC360 scanner to achieve the necessary accuracy. Due to its light weight, we were able to install it on a custom rig designed and constructed by ARC, which allowed the scanner to be attached to structural members and operated remotely at high altitudes.
When compared to the survey control, the measured accuracy of the registered scans was 1/8” or better.
Critically, the registered point cloud now needed to be converted into a highly accurate, as-built model. The biggest challenge we faced involved modeling the static tower at LOD 400 while still maintaining the specified accuracy of +/-5/8”. Structures tend to deflect under load, and this deflection – combined with construction tolerance errors – had resulted in a structure that was far from perfect. With a background in structural engineering and building documentation, RC Monkeys managed to document the real-world conditions of the static tower in Revit by distributing the errors across all the members. The result was a fully connected, LOD 400 model that met the represented accuracy specification and ensured that all the steel perforations were documented, color-coded, and scheduled for ease of use.
Key Characteristics
Seamless integration with client’s standards
70% of the building modeled at LOD400
30% of the building modeled at LOD300
+/- 5/8” represented accuracy