Extension of Euskalduna Conference Centre and Concert Hall: A Contemporary Application of Irregular Reciprocal Frames

Reciprocal frame structures, formed by a set of self-supported elements in a closed circuit, have long been used since antiquity to cover large spans with small elements. The roof structure of the Euskalduna conference centre and concert hall extension in Bilbao, covering an irregu- lar geometry of 3000 m2 with a maximum span of 45 m, presented an interesting opportunity to revisit the concept and to apply these classical systems. Furthermore, its analysis and develop- ment led to an interesting discussion on reciprocal frames. They showed great sensitivity of these systems to the local modification of a particular element, establishment of irregular load paths, mobilisation of almost the entire sys- tem when locally applying a punctual load and, finally, its large deformability. Besides, reciprocal frames present particular construction complexities and possibilities due to the moderate length of the structural elements, the predominance of shear-only connec- tions and the necessity of the entire system to be completely erected to guarantee its stability. Euskalduna extension, completed in 2012, is one of the largest and a very par- ticular case of irregular reciprocal frame structures built in the world. It shows the formal possibilities and potentiality of reciprocal frames to respond to free and irregular geometries.

Book Review: Elastic Beams and Frames, by J. D. Renton

The book represents a very interesting example of the possibility to combine in a single publication basic theory of structures and quite advanced topics on the same subject. The author fulfills this objective in a reasonable size book, less than 400 pages divided into 15 chapters averaging 20 pages each plus 9 short appendices. A diskette is also included in the book. This diskette contains training as well practical executable programs on different aspects of structural analysis, such as cross-sections properties,general-purpose computer programs for the static, dynamic and stability analysis of simple bar structures, etc. The book figures are didactic and have been carefully drawn.