Temple Galaxia – Burning Man
By Robin Ko | March 18, 2019
Structural Shoring
Burning Man is an annual gathering held for one week every year in the harsh and unforgiving Black Rock Desert of Nevada where a community comes together to construct a temporary city filled with art installations and camps dedicated to radical self-expression and self-reliance. Participants are expected to be collaborative, inclusive, creative, and connective and in the end, leave no physical trace of the event out of respect for the environment. The centerpiece of last year’s event was the Temple Galaxia, a roughly 195’ diameter by 65’-tall spiral mountain-like structure constructed from numerous timber triangular trusses, making its construction very difficult and complicated.
Although the scaffold shoring ring at the heart of the temple Galaxia construction seems very straightforward at first glance, the hidden complexity of the design derives itself from the multi-directional loading conditions created by Galaxia’s sheer size, weight, irregular shape, and multiple phases of construction. With little room for error due to the limited construction window, a remote desert location, and the tight tolerances that would be required to ensure the final integrity of the structure, the project offered some unique challenges to overcome.
The scaffold would initially need to support the roughly 20-ton weight of the upper crown, which would also result in a top-heavy wind load. Then, as each of the (20) spiraling petals of the temple were constructed, an additional vertical, radial, and tangential load would be introduced to the scaffold system from the odd shape of the leaning trusses. Eventually the scaffold would need to support the worst-case scenario which would include the wind impact from the full profile of the Galaxia structure along with the imbalanced loading caused by the lean and twist of only half of the spiraling truss petals being in place. This resulted in a design requiring a spiraling bracing pattern to match the structure that it was supporting and extra shoring towers to prevent the individual petals from twisting during their installation.
The second challenge would be developing an anchorage system capable of supporting such loads. Considering the “leave no trace” policy of the event, providing any concrete footings or deadmen was out of the question. And given the remote desert location, using any heavy-duty anchorage that would require any specialized equipment would not be possible. Thus, we were limited to very low-capacity earth anchors creating the need for 88 bracing points around the perimeter of the scaffold supporting the spider web of ratchet straps required to tie down the scaffold structure.
The next challenge would be to create an interface between the Galaxia structure and the scaffold that could adequately absorb and transfer the loading. This cradle structure would need to be custom built to fit Galaxia’s unique shape, rigid enough to maintain the proper elevation for the Galaxia build, and yet flexible enough to release the scaffold from underneath the temple once construction was completed. Initially, we considered supporting the Galaxia members directly from the metal scaffold framework, but after further consideration, using timbers would offer the flexibility we would need to handle potential field variances and meet the unique factors involved in Galaxia’s construction process. Two continuous 6×12 timber rings were constructed over the top of the scaffold legs supporting crossing timber ledgers with reinforced notches cut specifically to align with Galaxia’s spiraling truss petals.
After 22 days of construction, 12-hour workdays, and over 10,000 man-hours in the extreme temperatures of the desert playa, the temple Galaxia was successfully completed to the cheers of the volunteer construction crew. One of the most difficult parts of the process was removing the scaffold, which had shouldered the brunt of Galaxia’s weight amidst 30-40 mph dust storms and a complicated construction process. Workers speculated that the settlement of the Galaxia structure would be anywhere from 1 mm to complete and utter failure, but the whole timber cradle and scaffold ring worked out as planned. The temple became self-supporting after settling about 5” once the scaffold was removed, which was a pretty amazing result considering the complexity of the construction. Overall, the project was a huge success and ultimately a testament to all those who helped translate this true work of art into reality.
All pictures courtesy of Bruce Schena