MultiCare Central Utility Plant

2014

In the aftermath of a major earthquake, it’s crucial that hospitals remain fully operational. How did PCS improve seismic resilience at the Central Utility Plant (CUP) at MultiCare Tacoma General Hospital?
Our task was to make sure the hospital could keep running during and after a seismic event. Like many hospitals, Tacoma General runs on hydraulic power produced by the CUP. Many steam lines begin and end at the CUP, so they were an Achilles heel for the hospital: if the lines broke during an earthquake, then the hospital would effectively shut down. We had to seismically anchor the piping so it would stay in place and continue to function after an earthquake.
 
What was challenging about this particular project?
Our engineers needed an accurate model of the space to determine the best locations to place the seismic anchors, but the piping was so complex and densely interwoven that it simply wasn’t possible to use traditional as-built methods to determine the existing piping layout.
 
What bold solution did you use to solve this problem?
We used point cloud scanning to create an accurate 3D visualization of the space, then generated our Revit model based on the scans.
 
How does point cloud scanning work?
A 3D scanner on a tripod uses laser beams to record the X, Y, and Z-coordinates of millions of points on surfaces that the scanner can “see” from its vantage point. All those points are then assembled to create a fuzzy 3D image of the space.
 
What other challenges did the project team overcome?
The scanner’s lasers can’t record anything beyond the first object they hit – so the pipes behind the ones in front will only be recorded in bits and pieces where the lasers can “see through” gaps in the array. Our Revit model had to show every pipe flowing continuously through the space, not just the incomplete segments from the scan. Our process was a bit like a Sudoku puzzle in 3D: model the obvious pieces captured by the scan first in small chunks, then piece them all together and use deduction to fill in the gaps of missing pipe. I wrote some custom software especially for this project that helped streamline that process.
 
What did you take away from this project?
How invaluable point cloud scanning can be! The point cloud gave us a way to “see” the site from many angles with perfect accuracy while we modeled it, reducing mistakes in the modeling process and allowing for smoother and less disruptive installation of the seismic anchorage. With our Revit model, the engineers were able to design anchors to secure the piping—ensuring Tacoma General Hospital will keep on running regardless of rain, shine, or earthquakes.
 
 
Sage Cowsert is a Senior BIM Technician with more than 20 years of experience at PCS. Sage is a valued resource for his coworkers as well as his clients; with an eye for streamlining everyday processes and complex modeling challenges, he frequently builds custom programs that boost efficiency firm-wide.