EXPANSION JOINT CASE STUDY

Project: Exploratorium Science Museum
Location: Pier 15 and 17, San Francisco
Architect: EHDD

The Project: In 1969, noted physicist Frank Oppenheimer opened the doors to a radical new concept, an engine of curiosity dedicated to lifelong learning named the Exploratorium. Back then it was the only museum of its kind, while today it is known for starting a movement that transformed education by serving as the prototype for more than 1,000 hands-on, participatory institutions that now exist around the world. The Exploratorium also pioneered the idea that science institutions are bona fide sources of teacher education too. As a research and development laboratory for public learning, the Exploratorium receives more National Science Foundation (NSF) funding than any other non-university institution nationwide.

For most of its life, the Exploratorium has been located at the Palace of Fine Arts in San Francisco, which is far from the city center on the western outskirts of town. In spring of 2013, after years of fundraising, design, and construction, it moved to a 9-acre campus in the center of the city right between the Ferry Building and Fisherman’s Wharf. This new campus on San Francisco’s Embarcadero encompasses two historic waterfront structures: Pier 17, built in 1912, and Pier 15, built in 1915, with a major renovation in 1931. The stated design goal was not replacing these landmark buildings but rather bringing them to life once again. The one new structure on the site—the glass and steel Bay Observatory—will provide a transparent lens on the waterfront, offering a contemporary counterpoint to the historic surroundings.

The Challenge: The buildings are large in this $220-million project, requiring it to be broken up into discreet fire-separated sections. This is not unusual but is compounded by the fact that one of the building juts out into and over the saltwater of the San Francisco Bay. Further, this location is in a well-known active seismic zone, which meant that any joints between building sections needed to be flexible enough to move with seismic forces, maintain the fire rating, and continue to provide fire safety. In addition, the goal was to create a LEED Gold, net-zero-energy facility with features that push the envelope of green technology and environmental awareness.

The Design Solution: A single source was specified to provide the entire expansion joint and barrier package for the Exploratorium project. Almost 1,500 linear feet of interior and exterior seismic expansion joints are used throughout the building. Joint widths varied from 8 inches to as wide as 27 inches. Of that, nearly 95 percent of the joint systems were custom designed and built, including several joints incorporating 3/8-inch thick aluminum diamond plate. Where these joints bridged fire separation areas, waterproof fire barriers were specified and installed. The fire ratings were needed to maintain the safety of the walls, floors, and roof systems that made up the fire separations. The waterproof component was needed to withstand the moist and humid conditions of being over the water. Finally, designers specified particular coatings on many of the exposed joint systems to fight saltwater degradation and assure durability.

The Results: The hands-on exhibits of the finished project explore biology, physics, listening, cognition, visual perception, social behavior, and the environment. And in the spirit and style of the Exploratorium, there is a display dedicated to the expansion joints used. This display helps visitors and students understand a building’s constant battle with Mother Nature, and how expansion joints help a building withstand thermal and seismic movement, protecting the building and the people using it.