Insulated walls movement

[StrEngr2021]

GC has reported movement for insulated walls in BOTH directions i.e. in-plane and out-of-plane movement. While out-of-plane movement(bowing) can & does occur in insulated precast walls, the in-plane movement is baffling. The panels are connected to steel braced frame for lateral support, but the connection is with oversized holes to allow movement in vertical and horizontal directions. Thus the only force transfer between the 2 is push/pull type forces. Please let me know if you’ve come across this type of problem. Useful insight will be helpful and much appreciated.

 

[jayrod12]

Why aren't they connected to the steel for in-plane loads? What is supposed to stop the precast walls from racking? Self weight? Are the precast walls fastened to the roof or floor structure above?

 

[StrEngr2021]

They are not connected to steel frame for in plane movement to avoid transfer of lateral shear between the two. Panels are fastened to continuous footer with connectors that resist both overturning and shear forces.

 

[dhengr]

StrEngr2021:
Given the way you think the steel structure and the wall panels (planks?) interact due to lateral loads, you had better be very careful how you detail the connections btwn. the panels and the steel, and those btwn. the panels at their joints. In plane, the panel wall sections, and each individual panel for that matter, are much stiffer than the steel structure. They do not flex, they do not rack or parallelogram in plane. They move as rigid panels (rigid bodies), and rotate about one or the other bottom corners, one corner in compression and the other lifting up, depending on load direction, and this causes considerable movement btwn. panels, along their joint length, at every vert. joint btwn. adjacent panels (a large shear flow). And, this problem of load transfer becomes even more complicated at wall panel corners (bldg. corners) and around lines of braced stl. framing.