The Analysis of Irregular Shaped Structures

Diaphragm and shear wall analysis is given one of two treatments in engineering education: a very basic overview using the girder analogy or a highly specific guidance based on tall, regular buildings. Neither treatment exposes the reader to the very common irregularities that occur in low and mid-rise buildings, making lateral system design a nuanced art with little codified guidance. Terry Malone and Robert Rice explore these common irregularities in great detail throughout this textbook.

IMG_8688Malone and Rice rely on meticulously worked examples to explain each concept in the text. Explanations use visual analysis methods — something that allows the authors to focus on the qualitative explanations rather than the number crunching that can often bog down engineering text. This is a wise choice that makes the design process transparent. Code provisions are mentioned and followed, but the reality is that codified lateral design is often too general for application to irregular structures. A degree of rational analysis is often required to sort out the load path. The authors help build awareness and confidence in order for the reader to develop this rational sense.

One issue I noticed with the book is that, although the material is well documented with referenced literature, the recommendations provided are often regarded as very conservative in design. Given the construction of wood diaphragms over the last thirty years, it is expected that many designers do not take the rigorous route that Malone and Rice suggest. Rather, the lateral system is either over-designed or over-simplified. Unfortunately, a consequence of either of those systems is poor or unpredictable function. On the other hand, the additional cost that is involved with the rigorous textbook solutions (ie. metal connectors, development of collectors, continuity, etc.) is often not practical given the “satisfactory” performance of past construction. Once again, engineers can expect to find themselves celebrating the additional knowledge and processes learned after reading “The Analysis of Irregular Shaped Structures” while also feeling confused why the level of rigour described in the textbook examples is not consistently followed in practice.

This is a highly recommended book and one that will help develop engineering intuition in lateral design.

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