Testing of cantilevered signal, sign and light poles at Lehigh University
resulted in these recommendations: bending stresses caused by horizontal
shear forces can be ignored when the exposed length (top of foundation to
underside of leveling nut) is less than one bolt diameter. For greater than
one bolt diameter, use a fixed-fixed beam model.
San Jose, CA 95126
From: jwhitty(--nospam--at)itac-net.com [mailto:jwhitty(--nospam--at)itac-net.com]
Sent: Wednesday, January 31, 2001 7:59 AM
Subject: Unfinished Business
I have a major problem with some of the finishing done on various structures
that I've seen out in the public domain. These structures usually are along
the highways that I travel and include major overhead signage/signal
structures as well as towers for cellular antennas.
It seems the structure is leveled via levelling bolts but is never grouted.
In addition, there are no shear lugs on the bottom of these columns. Some
of the projections are quite large and the number of bolts quite few. Going
by the various schools of thought - some rely on friction between base
plates and grout in friction against vertical load and some rely on shear
lugs for lateral force transfer. Seems to me that these structures transfer
via bolt bending. Not sure the designer intended it this way. Some of
these lateral loads could get quite large.
Am I making a mountain out of a mole hill? Are contractors lazy? Is this
what the designer intended?
Let me know you alls thoughts.
John Whitty, P.E.