Comment Submittal Form
(Please use a separate form for each ballot item comment. Add pages if required)
Masonry Standards Joint Committee
Main Committee Ballot: MSJC 2011-11
Closing Date: October 8, 2010 at
11:59 pm Eastern Time
Ballot Number:
Vote:
From: Richard Bennett
Phone:
865-974-7540
E-mail:
rmbennett@utk.edu
11-V-002
Negative
Reason for Above Vote:
Chapter 5 is based on the observation of real buildings, not laboratory specimens. Like
the commentary says, it is based on experience. Empirical design is a procedure of
sizing and proportioning masonry elements. It is not design analysis. Rules of design
have been developed based on behavior of whole buildings, and not just isolated walls.
The laboratory for empirical design is all the buildings that have been built. The proper
way of determining the safety level of empirically designed buildings is to observe their
behavior in the real world.
This ballot item provides no empirical evidence to support prohibiting ignoring the
opening in empirical design for hollow ungrouted units when Ws is less than 4 feet. The
probabilistic analysis provided in the public comment is based on analysis of isolated
walls. A proper probabilistic analysis of empirically designed structures would also
include their observed performance. For example, a Bayesian analysis could be used
whereby probabilities are updated based on observed performance.