Earthquake Impact Design Features
The Richmond City Hall is built to the most current research on earthquake design and building code. Although not "Post Disaster" - meaning fully functional after a significant earthquake it will be structurally sound for evacuation.
Movement experienced on the upper floors during an earthquake is meant to happen. The structure is designed to be "ductile" - that is, to bend and sway with the earthquake waves. This is similar to the movement you may witness on your car antenna - the further away from the base the more it sways. The Meeting House and the tower are designed as two buildings. This is because the tower could be swaying at a different rate than the low rise Meeting House. At the second floor bridge, approximately where the reception area sits, there is a rubber joint in the floor and in the sprinkler lines that allow the one building to react independently of the other. It's kind of like the tower is dancing to one song, with the 8th floor really getting into it, while the Meeting House is dancing to a different song or sitting out completely.
All the equipment in the ceilings, including the lights and air conditioning units, are anchored back to the slab with steel cables. The large air conditioners on the roof are actually mounted on springs. The windows have rubber gaskets, which allow for movement. All of the high bookcases and high filing cabinets are secured to a wall. The glass windows in the private offices are installed with earthquake design. If something falls on the floor, the aisle ways are wide enough to allow access to exit.
The Olympic Washington Earthquake, which took place February 2000, registered a 7.0 magnitude resulting in an impact on Richmond City Hall of approximately 2.5 - 3.0 magnitude. Investigation by Facility Management staff and the building's design structural engineer reported no physical impact. The building behaved exactly as designed for that magnitude of earthquake.
If you watched the Seattle news after the earthquake, you may have noticed that most of the damage occurred in the old brick buildings at Pike Street. These old buildings are not built to sway and because of the rigid nature they crack and the bricks fall off. The Space Needle, on the other hand, swayed enough to cause sea sickness, but didn't have significant structural damage.
We do have bricks, blocks actually, in the City Hall building. The exercise room and service rooms near the loading bay are built of block. The block walls are not structural walls and they are connected to the slab.