Structure for Architects E-Book

Ramsey Dabby

• Herausgeber: John Wiley & Sons
• Kategorie: Geisteswissenschaft
• Sprache: Englisch

Seitenzahl: 227

Veröffentlichungsjahr: 2012

Beschreibung

An introduction to the concepts and principles of architectural structures in an easy-to-read format

Written as an easy-to-understand primer on the topic, Structure for Architects engages readers through instruction that uses a highly visual format and real-world examples to underline the key facets of structural principles that are essential to the design process. Eschewing complicated mathematics and technical jargon, Structure for Architects demystifies the subject matter by showing it in the context of everyday situations, giving architects and architectural technologists a clear understanding of how to incorporate structural principles into their designs.

Highlights of this book include:

• A rich collection of drawings, photographs, and diagrams, spread throughout the text, which demonstrate fundamental structural concepts using everyday examples

• An overview of structural design basics, as well as a summary of structural forms

• A look at the design implications of steel, reinforced concrete, and wood

By providing an overall view of structures that covers the essentials of what architects and architectural technologists need to know, Structure for Architects is a valuable tool for illustrating the importance of designing with structure in mind and for learning the basics that are necessary for collaborating confidently with project team members.

Leseprobe

Contents

Cover

Title Page

Copyright

Preface

Chapter 1: Architects, Engineers, and Design

Chapter 2: Stability and Strength

Chapter 3: Loads

3.1 Gravity Loads

3.2 Lateral Loads

3.3 Dynamic Loads

3.4 Impact Loads

3.5 Load Paths

Chapter 4: States of Stress

4.1 Tension

4.2 Compression

4.3 Shear

4.4 Torsion

4.5 Bending

Chapter 5: Forces, Movement, Levers, and Moment

5.1 Applied and Reactive Forces

5.2 Translational Movement

5.3 Rotational Movement

5.4 Levers

5.5 Moment

Chapter 6: Stability and Equilibrium

6.1 Introduction

6.2 Translational Equilibrium

6.3 Rotational Equilibrium

6.4 Sign Conventions

6.5 The Equilibrium Equations

6.6 Free-Body Diagrams and Familiar Examples of Equilibrium

6.7 Introduction to Bending in Beams

Chapter 7: Working with Forces

7.1 Forces, Vectors, and Lines of Action

7.2 Combining and Resolving Concurrent Forces

7.3 Familiar Examples of Concurrent Forces

Chapter 8: Supports, Reactions, and Restraint of Movement

8.1 Roller and Frictionless-Surface Supports

8.2 Pinned Supports

8.3 Fixed Supports

8.4 Hanger Supports

8.5 Familiar Examples of Support Conditions

8.6 Stable or Unstable?

Chapter 9: Load Distribution

9.1 Point Loads

9.2 Distributed Loads

9.3 Equivalent Point Loads

9.4 Uniformly Distributed Loads

9.5 Non-Uniformly Distributed Loads

Chapter 10: Introduction to Beams

10.1 Beam Types

10.2 Predicting Deformation, Deflection, and Beam Behavior

10.3 Statically Determinate and Statically Indeterminate Beams

10.4 Other Considerations for Beams

Chapter 11: Framing Systems and Load Tributary Areas

11.1 One-Way Systems

11.2 Two-Way Slab and Beam Systems

11.3 Two-Way Slab/Two-Way Joist Systems

Chapter 12: Shear and Moment Diagrams for Beams

12.1 Sign Conventions

12.2 Typical Shear and Moment Diagrams

12.3 Creating Shear and Moment Diagrams

12.4 Comparing V and M for Uniformly Distributed Versus Concentrated Loading

12.5 Summary of Deformation, Shear, and Moment Relationships

Chapter 13: Stress, Strain, and Properties of Materials

13.1 Stress

13.2 Strain

13.3 Stress versus Strain

13.4 Properties of Materials

13.5 Stress Distribution Diagrams

Chapter 14: Introduction to Columns

14.1 Columns, Compression, and Bending

14.2 Column Loading

14.3 Column Compression

14.4 Column Bending

14.5 Leonhard Euler and Column Buckling

Chapter 15: Frames, Rigidity, and Lateral Resistance Systems

15.1 Triangular Frames

15.2 Rectangular Frames

15.3 Making Rectangular Frames Rigid

15.4 Lateral Resistance Systems

Chapter 16: Introduction to Trusses

16.1 Introduction

16.2 Trusses as Beams

16.3 Types of Trusses

16.4 Design Considerations

16.5 Truss Joints

16.6 Truss Loading

16.7 Truss Analysis

Chapter 17: Structural Walls

17.1 Loads and Deformational Stresses

17.2 Stresses and Wall Construction

17.3 Retaining Walls

Chapter 18: Soils and Rock

18.1 The Earth's Interior

18.2 The Earth's Crust

18.3 Natural Soils

18.4 Groundwater

18.5 Engineered Fill

18.6 Foundation Settlement

18.7 Soil Bearing Capacity and Subsurface Conditions

Chapter 19: Foundations

19.1 Shallow Foundations

19.2 Deep Foundations

Chapter 20: Summing Up

Creation of Stress

States of Stress

Resistance to Stress

Appendix 1: Structural Forms

Appendix 2: Structural Materials—Steel

A2.1 Composition And Manufacture

A2.2 Characteristics and Properties

A2.3 The American Institute of Steel Construction

A2.4 Grades of Structural Steel

A2.5 Shapes and Forms

A2.6 Joining Steel

A2.7 Decking

A2.8 The Design/Fabrication/Erection Process

A2.9 Related Terms

Appendix 3: Structural Materials—Reinforced Concrete

A3.1 Composition and Manufacture

A3.2 Curing

A3.3 Characteristics and Properties

A3.4 Related Terms

Appendix 4: Structural Materials— Wood

A4.1 Source and Manufacture

A4.2 Products

A4.3 Characteristics and Properties

A4.4 Structural Considerations

A4.5 Related Terms

Appendix 5: Properties of Sections

A5.1 Center of Gravity and Centroids

A5.2 Moment of Inertia

A5.3 Section Modulus

A5.4 Radius of Gyration

Appendix 6: Basic Trigonometry

A6.1 Basic Trigonometric Functions of a Right Triangle

A6.2 Basic Trigonometric Values of Frequently Used Angles

A6.3 Proportions of Special Right Triangles

A6.4 The Pythagorean Theorem

Index

This book is printed on acid-free paper.

Copyright © 2012 by John Wiley & Sons, Inc. All rights reserved

Published by John Wiley & Sons, Inc., Hoboken, New Jersey

Published simultaneously in Canada

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Library of Congress Cataloging-in-Publication Data:

Dabby, Ramsey. Structure for architects : a primer / Ramsey Dabby and Ashwani Bedi. p. cm. Includes index. ISBN 978-0-470-63376-2 (hardback); ISBN 978-0-470-90294-8(ebk); ISBN 978-0-470-90246-2 (ebk); ISBN 978-0-470-90249-3(ebk); ISBN 978-0-470-95096-8(ebk); ISBN 978-0-470-95113-2(ebk) 1. Architecture. 2. Structural engineering. 3. Thought and thinking. I. Bedi, Ashwani. II. Title. TH845.D33 2011 624.1'7–dc22

2010054173

Preface

The concept for this preliminary textbook arose a few years ago when we jointly taught a Structures course to architectural students in the Architectural Technology Department at The New York City College of Technology. Noting the lack of an appropriate introductory text covering the intended topics, we decided to draw upon our professional and classroom experiences and began work on a structures textbook primarily aimed at the architectural student. Thus began a journey that has spanned over several years and continues to evolve.

Architects tend to think visually, in concepts, while engineers tend to think mathematically, in details. The disparity between the way architects and engineers perceive and process information is not addressed by most structural engineering textbooks, which focus heavily on technical aspects and often intimidate the architectural student. Actually, structures is the most intuitive of engineering disciplines, its principles easily perceived and visible in countless everyday situations. Our intent in this work is to de-mystify structural principles and present them in an intuitive, easy-to-read, and graphically friendly format.

We wish to thank Tim Maldonado, former Dean of the School of Technology at The NYC College of Technology, for his encouragement and guidance especially during the early stages of development. We also wish to thank Stella Deporis, R. Elias Dabby, and Latif Dabby for their advice and inspiration, as well as Andrzej Flakowicz, and Rodrigo da Silva (our former student and now graduate architect) for their much-valued early assistance on the illustrations.

While we collaborated with and also thank our many other academic and professional colleagues, we would not have imagined this work to be complete without the thoughts and reviews from two very talented engineers—our dear friends, Tom Michon and Sunil Saigal. Tom is simply one of the most brilliant practicing structural engineers with whom we've ever had the pleasure of knowing and working. Sunil, Dean of The Newark College of Engineering at NJIT and Distinguished Professor of Structures, has always placed his students before anything else. With an avid passion for structures and academics, Tom and Sunil's primary desire was to help develop quality technical material for students, while keeping it easy-to-understand.

We would like to express our appreciation to Wiley Acquisitions Editor Paul Drougas and Senior Production Manager Kerstin Nasdeo for their confidence, patience, and publishing guidance.

Finally, we wish to thank our families who wondered about, and put up with, our discussions lasting hours on end. Barbara and Kiran, we could not have accomplished this without your support and understanding—we lovingly dedicate this to you.

We welcome and appreciate any comments, suggestions, or corrections by the reader.

Ramsey Dabby, RA Ashwani K. Bedi, PE [email protected]

CHAPTER 1

Architects, Engineers, and Design

To the general public the distinction between architects and engineers, and their relationship to design, is blurred. What exactly is the difference between an architect and an engineer? Between architecture and engineering? Don't architects, after all, study engineering? What do engineers have to do with design? Isn't design what architects do? And if architects and engineers are so highly trained in design and construction, why is a third group—contractors—needed to construct buildings? The confusion is understandable.

For centuries, there was little, if any, distinction among architects, engineers, and builders. With the advent of the Industrial Revolution, the world became increasingly complex. The guild and trades system, in which skills and techniques were handed down from generation to generation, began to break down. By the mid-1800s, architecture in the United States evolved into a profession distinct from engineering and construction.

There are many ways to define architecture, but perhaps the most expressive definition was the one provided by Marcus Vitruvius Pollio, a first-century AD Roman writer, architect, and engineer. Vitruvius wrote De architectura, a Latin treatise on architecture, in which he asserted that a structure (architecture) must exhibit the three qualities of firmitas, utilitas, and venustas, loosely translated as strength, having soundness of construction; usefulness, having practical value or purpose; and beauty, giving pleasure and delight to those who experience it.

Figure 1.1 Denver International Airport, Denver, CO

Determining strength and usefulness is relatively easy. Determining beauty is more difficult, since each of us is free to decide what gives us visual pleasure and delight. With all due respect to Vitruvius, perhaps another way to define architecture is to simply call it the art and science of constructing.

Figure 1.2 Puente de la Mujer, Buenos Aires, Argentina

In modern practice, the knowledge and information needed to design and construct a large building requires many areas of expertise, too much for any one profession to know. The entire process of determining a building's appearance, the materials and systems to be used, and their configurations and sizes is broadly called design. Design falls mainly on the shoulders of architects and engineers. Architects have primary responsibility for determining the building's size and shape, along with the myriad architectural materials, finishes, and details. Engineers have primary responsibility for determining the mechanical, electrical, and structural systems, along with the many engineering calculations and details.

Figure 1.3 Hoover Dam, Boulder City, NV

Contemporary architects, as the leaders and orchestrators of most building projects, are trained as generalists and humanists conversant with aesthetics, planning, sociology, and economics, as well as engineering. By contrast, the training of contemporary engineers is highly technical and focused on a specific engineering discipline. Early engineering had only two disciplines, military and civil. As technology advanced, new branches of engineering such as mechanical, electrical, and chemical engineering emerged from civil engineering as individual disciplines. Structural engineering, however, the branch of engineering concerned with designing buildings and other types of structures to stand up and resist loads, has always been considered a part of civil engineering and remains so today.

Structural engineering is the engineering discipline most closely intertwined with architectural form. The best architecture exhibits a strong understanding of how forces move through a structure. Toward that end, the primary intent of this book is to increase the structural vocabulary of future architects. It is our hope that by doing so, the architect's dialogue with the structural engineer will be enriched, thereby affording architecture the opportunity to reach its fullest potential.

Figure 1.4 CN Tower, Toronto, Canada

CHAPTER 2

Stability and Strength

In a broad sense, all structural engineering can be reduced to satisfying two basic conditions: stability and strength.

Through stability, the various forces that act on a structure are kept in balance, preventing the structure from toppling, sliding, bending, or twisting.

Through strength, the size and physical makeup of the structural materials are made sufficient to withstand the various forces acting on them.

Let's use an example of a weightlifter, Andre, holding a barbell over his head in order to illustrate the concepts of stability and strength. Suppose that the barbell has a 100 lb weight on each end and that Andre is well trained and intuitively keeps his hands evenly spaced. Since the barbell is balanced by the spacing of his hands, and since Andre has the strength to support the 200 total lbs, Andre stands upright, in firm control of the barbell and weights (Figure 2.1).

Figure 2.1 Lifter Supporting Barbell and Weights

Now suppose that Andre's hands are not evenly spaced. The barbell would tend to tilt and eventually topple. Although he would be strong enough to support the 200 total lbs, he would be unable to control the load due to a failure of stability (Figure 2.2).

Figure 2.2 A Failure of Stability

Now suppose that Andre's hands are evenly spaced but that the weight on each end is increased from 100 lbs to 200 lbs. His arms and legs would tend to bow and eventually would buckle beneath the increased weight. Although he would be sufficiently well balanced to control the 400 total lbs, he would be unable to support the load due to a failure of strength (Figure 2.3).

Figure 2.3 A Failure of Strength

Without stability, the strongest of buildings will fail, and without strength, the most stable of buildings will fail. Not only must the building as a whole satisfy these two conditions, but every one of its components must do so as well.