The “zipper truss” is a focal point of the central commons at the John W. Olver Design Building — an elegant three-dimensional  wood and steel form integrating design and engineering.

 

Constraints:

irregular trapezoidal geometry of the space, a response to the site and massing

the desire for a column-free space to maximize flexible use

substantial load from the green roof terrace above

climate conditions and the need to accommodate significant snowdrift loading

 

Parametric modeling allowed the team to efficiently test options within the complex geometric constraints.

 

Solution:

The solution leveraged the fabrication methods of each component:

cast steel connectors — unique pieces were kept to a minimum.  A single cast shape was used as the central connector for each truss, with pin connections addressing the unique geometry at each individual truss.

off the shelf connectors — the Clevis connectors attaching the steel rods and glulam diagonals were all standard components.

glulam diagonals — taking advantage of the reductive process of CNC milling to cost-effectively fabricate unique timber elements.  Since each mass timber element is individually fabricated, the unique diagonal members don’t add significantly to the cost.

 

Assembly:

Easy peasy