Engineering made simple
Every engineer gradually realises the limitations placed upon the
exactness of the final product, from the envisaged mathematical model,
intended or abstracted at the commencement of such a design.
 This
inexactness increases gradually from Pad-Combined-Strip-Raft in an
ascending nature. While several geometrical attributes are altered to
make the reality resemble the analytical model as closely as possible,
there is no way to alleviate this disillusionment of being unable to
crate a back to back foundation design, such as, in the case of
Superstructures.
The problem herein is in the fact that while engineers are capable of
assessing the Loading Patterns of a Superstructure to a very high degree
of accuracy, they are unable to set the same degree of accuracy to the
Soil Reactions acting upon foundations of such structures, although such
Reactions are the result of that same Loading Pattern referred to above.
As a reflection of this difficulty, it is an established
understanding that, while the many “Structural Analytical Computer
Programs” yield exact results for Superstructures of Buildings,
Retaining Walls, Bridges and Silos - the foundation aspect of these are
only an approximation, based upon the numerous assumptions that are
forced upon the engineer, to achieve a tangible result.
What Eng. D. F. M. Perera has done, has its real value in relieving
the engineer of this - feeling of inexactness- by incorporating a pseudo
condition in the analytical data that is fed into the computer and
thereby forcing the computer model to proceed as in the case of a
Superstructure and yield a result that is very highly compatible with
the real Loading Pattern.
As expressed at the launching ceremony of the book, he has “provided
a virtual system of statically determinate alternate supports to an
existing system of forces already in equilibrium, while defining it to
be of null value, so that the original equilibrium is undisturbed.
Then the computer is forced to proceed and analyse it as a normal
problem”.
Although the conceptual explanation of how this method works may
sound complicated and baffling, the user of this method will find the
tool suggested in his book through the various worked examples, to be
very simple and forthright when in use.
This I believe is of paramount importance of any tool, becoming
popular in its usage in the present day context.
On that note engineers who are faced with designing foundation will
no doubt benefit from the use of this Extremely Simple Tool that has
been named “Virtual Supports”, because it provides exact results, and
thereby allows them to investigate the cost-effectiveness of each of
their selected solutions for a particular foundation problem with ease.
Eng. Preminda Wijesurendra |
