There is no official "12th edition" of this book. The latest official edition is the 3rd Edition (or 2nd, depending on the volume). If you find a PDF labeled "Ed. 12", it is a fake, a compilation of notes, or an incorrectly labeled scan.
This book is designed to guide students and professionals through the calculation of support reactions and sectional forces in isostatic structures. It is unique for bridging the gap between classical manual formulations and the modern matrix formulations used in computer programming. Estatica Das Estruturas Humberto Soriano Pdf 12
: Analysis of bar structures, acting actions, and support conditions. There is no official "12th edition" of this book