Food for Thought: The Spirit of Engineering and How We
Should Use Our Structural Codes
During a lunch with one of my senior
colleagues, who I value as a mentor, I learned something quite valuable. “As
engineers, it is not the codes that we should be learning, but it is, in fact,
the spirit of engineering”. At first, I got a
bit taken aback. Throughout college and work, we have been learning and working
with structural codes and standards. Our professors and work supervisors always
told us to refer to the code for our structural calculations and designs. However,
the code only indicates WHAT the guidelines are for the design
process, but it does not indicate HOW the
guidelines are should be used. I was left to
ponder, perhaps, that we should not just blindly utilize the equations and
instructions in the code to design for our structures, but we should hold a
sense of curiosity of why these equations and guidelines are in the code. And hence, for our design process, we should use the spirit
of engineering.
To engineer is to create. To create safe
structures, we often have to overcome environmental difficulties and to solve
these problems using our specialized analytical skills on mathematics and
science that we accumulated over the years.
We need to have a clear knowledge about
structural systems and the selection of different systems in different situations, such as moment frames and
bracings. This is because different situations call for different methods. We
also need to understand the different types of loads, so that we can correctly
apply the appropriate load factors on the appropriate load cases. We should
understand the selection of appropriate and reasonable load combinations, since
using and combining all the load cases with their maximum values for analysis
is not the most
efficient case. For example, for roofs, it should not be expected
that there will be snow loads AND rain loads
at the same time. The science of load paths should be
understood to determine the application of load onto each
individual structure for structural analysis. For individual analysis, we need
to understand failure types (yielding or rupture) and material behaviour
(cracking and ductility) to understand how the structural members react to
various stresses and strains. Last and most importantly, we need to know how to
make reasonable assumptions of loads, materials, and structural systems for the
design process to ensure the structures that we design are within the ballpark
of safe structures. All of this is for the safety of the public. And all of this is not taught by the code, but it is
vested in the spirit of engineering itself.
It is true that the spirit of engineering, its
principles and concepts, ties in with the building codes. But, in order for us to use the codes, we must understand
why the codes are the way that they are now. Building codes provide us a form
of standardized limitation or uniformed guideline to design structures for its
strength and serviceability and to implement design force magnitudes that are
to be within the capacity or limit states. We must take into account that the
codes are established for control and public
safety. The codes are not here to lead us through the design process and to
have us input variables in their equations. If we blindly follow the code
without learning the fundamentals, we would not be engineering the design. We
do the thinking ourselves, not the code.
Moreover, the code is ever changing. Codes
change throughout history because of learned mistakes, such as structural
collapses during the earthquakes of 1971 in San Fernando and 1994 in
Northridge. Thus, the code is not perfect. Research and testing then are used to determine better limitations for the code
in order to reduce future failures and danger.
Yes, it is the law to follow the code. But if we are to do so, we need to be responsible and
use the code along with the spirit of engineering.