BIG seismic joints

Log Out | Topics | Search Moderators | Register | Edit Profile

Author Message Julie Root Senior Member Username: julie_root Post Number: 48 Registered: 02-2004 Posted on Monday, February 27, 2006 - 12:06 pm:    Any advice on products that can handle big seismic joints? 18"-20" nominal dimension. C/S and others seem to only go to 16". I am working on a public school in CA. We have the added code changes and a DSA review that puts more burden than usual on these joints. Richard L Matteo, AIA, CSI, CCS Senior Member Username: rlmat Post Number: 151 Registered: 10-2003 Posted on Monday, February 27, 2006 - 12:16 pm:    Don't you just love DSA? Try WABO (Watson Bowman Acme) they have some joints that go up to 24 inches. www.wbacorp.com Lynn Javoroski CSI CCS LEED AP SCIP Affiliate Senior Member Username: lynn_javoroski Post Number: 307 Registered: 07-2002 Posted on Monday, February 27, 2006 - 12:16 pm:    MM Systems has expansion joint covers for seismic conditions up to 24 inches. I only checked IPC (which doesn't go up that far), Watson-Bowman (where I got annoyed by their web site) and MM Systems. Access it off 4specs, Division 7. Easy to use. Good luck. Julie Root Senior Member Username: julie_root Post Number: 49 Registered: 02-2004 Posted on Monday, February 27, 2006 - 02:45 pm:    Thanks! John Bunzick, CCS, CCCA Senior Member Username: bunzick Post Number: 473 Registered: 03-2002 Posted on Monday, February 27, 2006 - 03:03 pm:    Is the joint 20 inches in its normal state? Or would it go to 20 inches in a seismic event? If the joint is normally 20 inches, and may move another 20 in a seismic event (total of 40 inches), it will fail completely. Mark Gilligan SE, CSI Senior Member Username: markgilligan Post Number: 57 Registered: 05-2005 Posted on Tuesday, February 28, 2006 - 07:10 am:    When dealing with seismic joints be clear what is the expected amount of movement. Often the engineer will specify the amount of movement that needs to be accomodated. The actual size of the joint typically needs to be larger. For example a 10" joint typically cannot close up to 0" Be clear whether the movement demands are different parallel to the joint. Typically the joint must be able to accomodate movement both perpendicular and parallel to the joint. Julie Root Senior Member Username: julie_root Post Number: 50 Registered: 02-2004 Posted on Tuesday, February 28, 2006 - 12:03 pm:    We are working through the nominal +/- percentage clarification. So for the nominal dimension that I noted in my inital post we are looking at 4" minimum because we have six stories. We also are looking at specific story drift so we are dealing with the biggest joint at the roof. We also have a unique area of the building that is small in footprint and tall that is where the biggest joint is occuring. We maybe at the point of constructing the small/skinny area with a brige configuration to the rest of the building so that the joint can be minimized. Most of my structural engineering colleagues are having to go to specific dynamic modeling to deal with DSA's party line. On a similar note we are having to design to a wind load factor that is for a building in a suburban site vs. the urban site we have. The engineers I am working with have tried on two different school buildings with DSA to prove dynamically the difference in a urban site, but they will not consider it. The difference in cost is substantial 1 to 1.5 M for each school.