Structural Analysis, Structural Insights, and Historical Interpretation

Abstract

In studying the architecture of the past the historian may ask a number of questions to which the expertise and analytical tools of the structural engineer are relevant. They are most directly relevant to knowing how the structure stands against gravity, wind, and earthquake. But some understanding of this may also be an essential basis for approaching other questions: How and in what sequence was it built? What changes has it undergone subsequently? Why, if at some stage it partly collapsed, did it do so? What was the original form if this no longer survives and is known only through incomplete records or partial remains? How was it designed? After a look at the available analytical tools and their use both in design today and in gaining an understanding of the behavior of early timber and masonry structures, possible approaches to these questions are reviewed and illustrated. Particular attention is given to the relative merits and shortcomings of finite element analysis and purely statical analysis. It is pointed out that the seeming accuracy of the results obtained by both methods is tainted by inescapable assumptions about unknowns and the simplifications that have to be made in modeling the real structure, though not in the same ways. Modeling is crucial and calls for skillful judgment which must be based on a wide intuitive understanding. One merit of the purely statical approach is that it helps more directly in developing this understanding. The illustrations show the importance of selecting the approach that is most appropriate to the questions to which an answer is desired.