Tai ngay!!! Ban co the xoa dong chu Engineering Iron and Stone Other Titles of Interest America Transformed: Engineering and Technology in the Nineteenth Century, by Dean Herrin. Displays a visual sampling of engineering and technology from the 1800s that demon- strates the scope and variety of the U. (ISBN: 9780784405291) History of the Modern Suspension Bridge, by Tadaki Kawada, Ph.; translated by Harukazu Ohashi, Ph.; and edited by Richard Scott, M. Traces the modern suspension bridge from its earliest appearance in Western civilization only 200 years ago to the enormous Akashi Kaikyo and Storebaelt bridges completed at the end of the twentieth century.
(ISBN: 9780784410189) Circles in the Sky, by Richard G. Chronicles the life of George Ferris, the civil engineer and inventor responsible for creating, designing, and building the Ferris Wheel. (ISBN: 9780784410103) Structural Identification of Constructed Systems, edited by F. Necati Çatbas, Ph.; Tracy Kijewski-Correa, Ph.
Emin Aktan, Ph. (ASCE Technical Report, 2013) Presents research in structural engineering that bridges the gap between models and real structures by developing more reliable estimates of the performance and vulnerability of existing structural systems. (ISBN: 9780784411971) Engineering Iron and Stone Understanding Structural Analysis and Design Methods of the Late 19th Century Thomas E. Library of Congress Cataloging-in-Publication Data Boothby, Thomas E.
Engineering iron and stone : understanding structural analysis and design methods of the late 19th century / Thomas E. pages cm Includes index. ISBN 978-0-7844-1383-8 (print : alk. Building, Iron and steel—History—19th century.
Building, Stone—History—19th century. Structural analysis (Engineering)—History—19th century.1′82109034—dc23 2014040873 Published by American Society of Civil Engineers 1801 Alexander Bell Drive Reston, Virginia 20191 www.org/pubs Any statements expressed in these materials are those of the individual authors and do not necessarily represent the views of ASCE, which takes no responsibility for any statement made herein. No reference made in this pub- lication to any specific method, product, process, or service constitutes or implies an endorsement, recommendation, or warranty thereof by ASCE. The materials are for general information only and do not represent a standard of ASCE, nor are they intended as a reference in purchase specifications, contracts, regulations, statutes, or any other legal document.
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Copyright © 2015 by the American Society of Civil Engineers. All Rights Reserved. ISBN 978-0-7844-1383-8 (print) ISBN 978-0-7844-7894-3 (PDF) ISBN 978-0-7844-7895-0 (EPUB) Manufactured in the United States of America. 22 21 20 19 18 17 16 15 1 2 3 4 5 Cover credits: (Front cover) Cabin John Bridge schematic courtesy of Special Collections, Michael Schwartz Library, Cleveland State University.
Cabin John Bridge photo (2014) by David Williams. (Back cover) Cabin John Bridge watercolor: Library of Congress, Prints & Photographs Division, Historic American Engineering Record, Reproduction No.: HAER MD,16-CABJO,1—12 (CT). Cabin John Bridge photo (August 1861): Library of Congress, Prints & Photographs Division, Historic American Engineering Record, Reproduction No.: HAER MD,16-CABJO,1—10. This book is affectionately dedicated to Colin Bertram Brown 1929–2013 But O for the touch of a vanish’d hand, And the sound of a voice that is still! Alfred, Lord Tennyson This page intentionally left blank Contents preface ix acknowledgments xi Introduction 1 PART I EMPIRICAL METHODS 7 1 Empirical Structural Design 9 2 Empirical Design of Masonry Structures: Brick, Stone, and Concrete 23 3 Empirical Design of Wood Structures 37 4 Empirical Design of Iron and Steel Structures 49 PART II ANALYTICAL METHODS 57 5 Introduction to Analytical Computations in Nineteenth-Century Engineering 59 6 Analysis of Arches 65 7 Analysis of Braced Girders and Trusses 79 8 Analysis of Girders: Beams, Plate Girders, and Continuous Girders 105 vii viii engineering iron and stone 9 Analysis of Columns 121 10 Analysis of Portal Frames 135 PART III GRAPHICAL METHODS OF ANALYSIS 147 11 Introduction to Graphical Methods of Analysis 149 12 Graphical Analysis of Trusses 161 13 Graphical Analysis of Arches 177 14 Graphical Analysis of Beams 191 15 Graphical Analysis of Portal Frames and Other Indeterminate Frames 203 PART IV SUMMARY AND CONCLUSIONS 217 16 Concluding Remarks—The Preservation of Historic Analytical Methods 219 Index 227 About the Author 233 Preface This book stems from a career-long interest in understanding how structural engineers worked in the past.
Although we admire the great works of Roman engineering and the medieval cathedrals of Europe, we tend to think that modern engineering is somehow superior to the engineering that produced these structures. The premise of this book is that, for all its evident differences, modern engineering cannot claim superiority to the engineering of any period in the history of civiliza- tion. That contemporary engineering is based on a different mindset and a different set of values from the work of any of these other periods is evident. But the works that appeared in the engineering of other periods are not reproducible by contemporary methodology: each age defines its own artifacts and its own ways of producing these artifacts.
The late nineteenth century is a particularly significant time for understanding contemporary engineering: Although nineteenth- century engineering is different from modern engineering in the sense described, this period is closely related to the present time. Although Roman and medieval engineering are defined primarily by experience- based procedures, they are somewhat informed by emerging ideas from speculative science. By the nineteenth century, however, ideas of science were sufficiently advanced, and ideas about the role of science in society, such as positivism, were sufficiently widespread that engineers began to think of themselves as scientists of a sort and began to think that they were responsible for applying scientific procedures to con- structed works. A particularly interesting feature that emerged from the study of nineteenth-century engineering methods was the efficiency and ix x engineering iron and stone accuracy of some of the procedures employed, as compared with the way we accomplish these tasks in the present age.
Particularly in truss design, both analytical and graphical, most of the procedures employed in the nineteenth century appear to be more efficient than those that we teach to students in contemporary engineering programs. The reliance on graphical methods, especially for trusses and arches, is particularly revealing of the late nineteenth-century mindset and does influence the actual form of the structures. In preparing this book I tried to focus on ordinary procedures used to design and construct ordinary works without placing emphasis on the exceptional engineering works that mark this period. Thus, although the reader can find references to the design of major works, most of the discussions in this book describe smaller works and the significant body of engineering design that went into their construction.
Acknowledgments I have been assisted greatly in many ways by many people in the preparation of this book. I have received particular assistance from several libraries that I would like to acknowledge. Daniel Lewis at the Huntington Library, San Marino, CA, has been particularly helpful, as have all the staff at the Avery Library at Columbia University, Ilhan Citak at the Linderman Library at Lehigh University, and the Special Collections staff at the Penn State University Libraries. I would like to acknowledge the assistance I have received from the staff at ASCE Press, particularly from Betsy Kulamer, Donna Dickert, and Sharada Gilkey.
I note the editorial assistance I have received from Mary Byers and from my brother, Daniel Boothby. I am also grateful for the support and assistance I have received from my colleagues, notably Jeffrey Laman, Louis Geschwindner Jr., Harry West, and Theodore Galambos. I am very grateful to Brice Ohl and Oluwatobi Jewoola, undergraduate students at Penn State University, for the preparation of the illustrations found throughout the book. I have received con- tinual help and encouragement from my friends at the Engineering Copy Center, Penn State University.
Finally, I gratefully acknowledge the patience, comfort, and help of my wife, Anne Trout, over the four years during which this book was developed. xi This page intentionally left blank Introduction This book concerns the methods used for structural engineering design in the late nineteenth century. Even as the opportunities for business, industry, and transportation were expanding during this time, the methods of the civil engineering and the structural engineering profes- sions were also expanding, in part to meet the demands of the expan- sion of industry. The intent of the present book is to capture, through investigation of writings, archival evidence, and examination of built works, the methods of structural design of bridges and buildings in the period from 1870 through 1900, roughly, the period known to histo- rians as the Gilded Age (1865–1893).
The value of this exercise is three-fold. First, understanding the intent of the designer is the key to a successful rehabilitation, whether architectural or structural. Second, the preservation of design methods for historic structures is at least as important as the preservation of the structures themselves. Third, many of the methods used in structural design in the late 1800s are valuable in their own right—quick, computationally efficient, under- standing of the behavior of the structure, and often giving special insight into the actual performance of the structure.
In undertaking the historic preservation of structures from the late nineteenth century, understanding design intent is important—the way that a bridge or building was designed and the way that the ele- ments of the structure were intended to function. Too often in historic preservation projects, we overlook the designer’s conception of the structure and impose a modern outlook on the structure, with the result that significant historic fabric is removed unnecessarily. One of the most widespread misunderstandings concerning historic structures is the idea that the older structures were designed for lighter loading 1 2 engineering iron and stone than modern-day structures. In fact, road bridges were designed for deck loads of up to 100 lbs/ft2 (see, for instance, Waddell 1894); the 1,000 lb/ft on a 10-ft lane dictated by this loading is well above the lane loading requirements of AASHTO HS-20 (AASHTO 2013).
Extraordinary vehicles, such as freight drays and road rollers, imposed very heavy loads on bridges. A passage of a steamroller is illustrated in the photo of the circa 1890 opening of the St. Mary’s Street Bridge in San Antonio, TX (Figure I-1). Equally important is under- standing in exactly what way nineteenth-century bridge design may have differed from modern design.
Although most bridge decks do meet the AASHTO uniformly distributed lane load requirement, few nineteenth-century bridge designers imposed limits on the con- centrated loads that the bridge could resist. A distributed load of 100 lbs/ft2 placed to create maximum force in each member was usually the only loading requirement. As a result, focusing attention on the floor system of a bridge under rehabilitation is more important than on the main load-carrying system, such as truss, girder, or suspension cable. Building floor loads used in the nineteenth century were similar to those used today.
However, the approach to wind loads on buildings was very different.