Lateral Stability of (Wood) Beam
by ken » Wed Aug 16, 2006 4:50 pm
Well described on the behavior of a wood beam under load.
The "hinged" bearing point caused a lateral beam deflection resulting the offset of the load bearing point condition.
The LVL beam basically is lacking a "kicker" like bracing system, at both sides of the beam centerline, to restrain the beam "top" flange from rotation. (Similar to the unbraced concept in designing the steel beam)
The suggestion to prevent this kind of problem will be:
-Ensure load bearing is uniform from floor framing to beam.
-Add 2x6 kickers at a proper spacing (ex. 3'-0" to 6'-0" o.c.) for lateral constraint.
-Adjust the column height properly to provide a continuous load bearing support.
-Provide adequate nailings between subfloor plywood and LVL beam.
(add glue to position the nail patterns)
-Field check the beam alignment along the bearing point (i.e. column location)
-Design footing pads properly
-Ken
