Structural Design E-Book

James R. Underwood

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

Seitenzahl: 935

Veröffentlichungsjahr: 2011

Beschreibung

Written for the practicing architect, Structural Design addresses the process on both a conceptual and a mathematical level. Most importantly, it helps architects work with structural consultants and understand all the necessary considerations when designing structural systems. Using a minimum of simple math, this book shows you how to make correct design calculations for structures made from steel, wood, concrete, and masonry. What?s more, this edition has been completely updated to reflect the latest design methods and codes, including LRFD for steel design. The book was also re-designed for easy navigation. Essential principles, as well as structural solutions, are visually reinforced with hundreds of drawings, photographs, and other illustrations--making this book truly architect-friendly.

Leseprobe

This book is printed on acid-free paper.

Copyright © 2007 by John Wiley & Sons, Inc. All rights reserved.

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

Published simultaneously in Canada

Wiley Bicentennial Logo: Richard J. Pacifico

No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, [phone], fax [phone], or on the web at www.copyright.com. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, [phone], fax [phone].

Limit of Liability/Disclaimer of Warranty: While the Publisher and the author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives or written sales materials. The advice and strategies contained herein may not be suitable for your situation. You should consult with a professional where appropriate. Neither the Publisher nor the author shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages.

For general information about our other products and services, please contact our Customer Care Department within the United States at [phone], outside the United States at [phone] or fax [phone].

Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. For more information about Wiley products, visit our web site at www.wiley.com.

Library of Congress Cataloging-in-Publication Data:

Underwood, James R.

Structural design : a practical guide for architects / James R. Underwood and Michele

Chiuini. — 2nd ed.

p. cm.

Includes bibliographical references and index.

ISBN 978-0-471-78904-8 (cloth)

1. Structural design. 2. Architectural design. I. Chiuini, Michele. II. Title.

TA658.U53 2007

624.1'771—dc22 2007013718

Table of Contents

Title Page

Copyright

Preface

In the Beginning: The Premise

Chapter 1: Introduction: Understanding Loads

1.1 Loads

1.2 Tributary Areas

1.3 Lateral Loads-Wind and Earthquakes

1.4 Lateral Loads: Wind

1.5 Lateral Loads: Earthquake

1.6 Loading Conditions

Chapter 2: Load and Resistance Factor Design

2.1 Load Combinations

2.2 Resistance Factors

2.3 Working Stress Versus LRFD Design

2.4 Elastic Section Modulus and Plastic Section Modulus

2.5 Shape Factor

Part One: Steel

Chapter 3: Materials and Properties

3.1 Structural Properties of Steel

3.2 Allowable Stress

3.3 Yield Stress

3.4 Standard Shapes

3.5 Fire Considerations

3.6 Surface Finishes

Chapter 4: Structural Elements and Systems

4.1 Member Types

4.2 System Selection

4.3 Low-rise Frame Systems

4.4 Mediumand High-rise Systems

4.5 Architectural Considerations

Section 1: Steel Bending Systems

Chapter 5: Preengineered Systems

5.1 Open-Web Steel Joist

5.2 Steel Decks

Chapter 6: Steel Beams

6.1 Beam Theory

6.2 Beams in Structural Systems

Chapter 7: Lateral Stability of Beams

7.1 Conditions of Stability

Chapter 8: Supports

8.1 Bearing Plates for Beams and Columns

8.2 Design of Bearing Plates

8.3 Column Base Plate

8.4 Design of Column Base Plates

Chapter 9: Web Yielding and Crippling

9.1 Localized Failure of Components

Chapter 10: Built-Up Beams

10.1 Built-Up Sections

10.2 Connection and Length of Cover Plates

10.3 Holes in the Web and in the Flanges

Section 2: Steel Axially Loaded Systems

Chapter 11: Columns

11.1 Column Theory

11.2 Built-Up Columns

11.3 Columns with Unequal Unbraced Lengths

Chapter 12: Tension Members

12.1 Types of Tension Members

12.2 Basic Design

12.3 Connection of Tension Members

12.4 Suspension Structures

Section 3: Steel Combined Systems

Chapter 13: Combined Axial Loading and Bending

13.1 Basic Considerations and Procedure

13.2 Sloping Beams

Chapter 14: Trusses

14.1 General Comments

14.2 Design Considerations

14.3 Truss Analysis

Section 4: Steel Connections

Chapter 15: Bolted Connections

15.1 Engineering Principles

15.2 Types of Bolted Connections

15.3 Bolts

15.4 Design of Connections

Chapter 16: Welded Connections

16.1 Welding and Types of Welded Joints

16.2 Stresses In Welds

16.3 Minimum and Maximum Weld Considerations

16.4 Framed Beam Connections

Part Two: Wood

Chapter 17: Materials and Properties

17.1 Physical Properties

17.2 Density and Weight of Wood

17.3 Protection from Decay and Fire

17.4 Design Values

17.5 Size Classifications

17.6 Adjustment Factors

17.7 Engineered Wood Products

Chapter 18: Wood Structures in Architecture

18.1 Construction and Architectural Philosophies

18.2 The Architect's Responsibility in Structural Wood Design

18.3 Selection and Configuration of Wood Systems

18.4 Framing Systems

18.5 Long-Span Systems

18.6 Bracing

Section 1: Wood Bending Systems

Chapter 19: Bending Members: Floor and Roof Systems

19.1 Floor Framing

19.2 Joist Design

19.3 Adjustment Factors

19.4 Engineered Joists

19.5 Subfloors

19.6 Fire Protection and Sound Insulation

19.7 Roof Construction

19.8 Bearing and Stress Concentration

19.9 Notched Bending Members

Chapter 20: Sheathing and Diaphragm Design

20.1 Diaphragm Construction

20.2 Shear Walls

20.3 Composite Bending Members

20.4 Plywood Structural Properties

20.5 Box Beam Design

Chapter 21: Timber and Laminated Timber Beams

21.1 Timber Beams

21.2 Built-Up Beams

21.3 Laminated Timber Beams

21.4 Design of Laminated Timber Beams

21.5 Types of Structures Using Glulam

Section 2: Wood Axially Loaded Systems

Chapter 22: Compression and Tension Members

22.1 Types of Compression and Tension Members

22.2 Design Procedure for Solid Columns

22.3 Built-Up and Spaced Column Design

22.4 Tension Members

22.5 Axial Compression and Bending

22.6 Axial Tension and Bending

Section 3: Wood Combined Systems

Chapter 23: Timber Truss Design

23.1 Truss Types

23.2 Deflection and Camber

23.3 General Design Procedure

Chapter 24: Arches, Vaults, and Domes

24.1 Two and Three-Hinged Arches

24.2 Preliminary Design of Laminated Timber Arches

24.3 Construction of Timber Arches

24.4 Domes and Vaulted Roofs

Section 4: Wood Connections

Chapter 25: Connections

25.1 Connecting Wood Members

25.2 Nails and Spikes

25.3 Adhesives

25.4 Glue Line Stresses: Rolling Shear

25.5 Bolts

25.6 Lag Screws

25.7 Wood Screws

25.8 Split Ring and Shear Plate Connectors

25.9 Design of Shear Plate and Split Ring Connections

Section 5: Wood Special Systems

Chapter 26: Permanent Wood Foundations

26.1 Types of Wood Foundations

26.2 Permanent Wood Foundation

26.3 Design of Footing Foundations

26.4 Basement Walls

Part Three: Reinforced Concrete (R/C)

Chapter 27: Materials and Properties

27.1 Structural Concrete Materials

27.2 Structural Concrete Properties

27.3 Reinforcing Steel

27.4 Fiber-Reinforced Concrete

27.5 Placement of Concrete

Chapter 28: Reinforced Concrete in Architecture

28.1 Structural Forms

28.2 Structural Design Issues

28.3 System Selection

Section 1: R/C Bending Members

Chapter 29: Beam Strength Theory

29.1 Stress and Strain in Flexure Members

29.2 Beam Design Formula

Chapter 30: Beam Design

30.1 Design for Bending Moment

30.2 Development of Reinforcement

Chapter 31: Shear in Beams

31.1 Shear Strength of Concrete

31.2 Design of Shear Reinforcement

Chapter 32: Slabs

32.1 Flat Spanning Systems

32.2 Flat Slab Design

32.3 Slab on Grade

32.4 Composite Sections

Chapter 33: Deflection

33.1 Creep and Deflection

33.2 Deflection Computations

Chapter 34: Footings

34.1 Foundation Design Criteria

34.2 Footings

34.3 Design Procedure for Footings

34.4 Peripheral Shear

34.5 Rectangular Footings

34.6 Simple Wall Footings

Section 2: R/C Axially Loaded Members

Chapter 35: Columns

35.1 Construction of R/C Columns

35.2 Design Method

Chapter 36: Walls

36.1 Concrete Wall Types

36.2 Design Requirements for Vertical Loads

36.3 Walls Designed as Compression Members

36.4 Horizontal Forces on Walls Below Grade

36.5 Retaining Walls

36.6 Shear Walls

Section 3: R/C Connections

Chapter 37: Connections

37.1 Connections of Footings and Vertical Structure

37.2 Anchors

37.3 Bearing Pressures

37.4 Concrete Supports

Section 4: R/C Special Systems

Chapter 38: Prestressed and Precast Concrete

38.1 Prestressed Concrete

38.2 Construction Techniques

38.3 Precast Concrete Shapes

Part Four: Masonry

Chapter 39: Materials and Properties

39.1 Masonry Units

39.2 Mortar and Grout

39.3 Mortar Strength

39.4 Construction

39.5 Design Requirements

39.6 Expansion/Control Joints and Reinforcing

39.7 Flashing

Chapter 40: Structural Systems

40.1 Masonry Construction

40.2 System Selection

40.3 Masonry Systems

Section 1: Masonry Axially Loaded Members

Chapter 41: Empirical Design of Walls

41.1 Limitations of Empirical Design

41.2 Working Stress

41.3 Lateral Stability and Shear Walls

41.4 Unsupported Height

41.5 Wall Thickness

Chapter 42: Allowable Stress Method

42.1 Unreinforced Masonry

42.2 Bearing and Concentrated Loads

42.3 Design of Shear Walls

42.4 Reinforced Walls

42.5 Column and Pilaster Construction

42.6 Column Design

Appendix A: Commonly Used Tables and Constants

Appendix B: Conversion Factors from U.S. Customary Units to SI Metric Units

Bibliography

References

Illustration and Table Credits

Index

Preface

The Three Issues Prompting the Creation of this second edition are the adoption or impending adoption of the International Building Code (IBC) as the standard for the United States and the almost exclusive use of load and resistance factor design (LRFD) for steel design. As one might expect, a number of other material-specific code changes have occurred since publication of the first edition, and these changes are also included.

We had hoped to include the relevant shape information and load tables that you would need, but this was not possible. The AISC offers a complimentary membership to students who are enrolled in university programs that will allow them to purchase the AISC Manual for Steel Construction at a 50% discount. Students need to initiate this membership early, since it can take a few weeks to obtain. With that membership, the manual can be purchased at the discounted price from their web site: www.aisc.org. Complimentary-membership application forms are available at that location as well. Students will also need the National Design Specification for Wood Construction, published by American Wood Council (2005 edition). This specification has been simplified into two basic manuals that are best used in their original form.

Wood and masonry design procedures are just beginning to make the change to LRFD procedures, and the codes are acknowledging these changes by creating adjustment factors in lieu of full-fledged revisions. For this reason, we are maintaining working stress or allowable stress design (ASD) procedures for these materials. We realize that this switching between different systems can be confusing, but in our opinion the alternative is even more confusing.

The IBC procedures for earthquake and wind loading are significantly more complicated than the previous versions. For this reason, we have included the Uniform Building Code (UBC) procedures for wind loading so that architects will have the option of using the much simpler UBC procedures at least for preliminary design. The IBC equivalents are included on our web site for those of you who have a morbid interest.

Some changes have occurred in concrete design to bring it more in line with the IBC load criteria, and better understanding of the material in context has created some relevant changes in the strength reduction or capacity reduction factors—Φ.

We have greatly expanded the explanations of example problems so that the logic may be more easily followed.

There has been significant progress in the introduction of metric tables in the AISC manual for those of you who are interested; however, we do not have complete reference material for all of the tables. To mitigate that deficiency, we have worked the problems in metric and for the final answers have converted those answers to SI units so that you can use the included tables as much as possible. It is also worth noting that many of the metric conversions are not “hard” conversions of actual sizes. We've generally included the “soft” conversions; that is, 2X4's are internationally known as 38X89, and 12, 16, and 24 in. spacings are 300, 400, and 600 mm. This may be confusing, but it is generally accepted practice outside the United States.

The Web offers the unique opportunity to present additional information as well as constant updates. We are introducing a web site www.wiley.com/go/ structuraldesign that will have additional instructor and student areas with information relative to teaching, solved example problems, and more complex information regarding rigid frames and statically indeterminate structures.

We also recommend that students refer to building construction manuals, such as the Architectural Graphic Standards and The Architect's Studio Companion, for types of structural systems, construction details, and graphic conventions. Other useful references that can complement this text are the IBC and trade organizations listed in the References with their web addresses.

Chapter 1

Introduction: Understanding Loads

1.1 Loads

In statics, loads are forces acting on structural components and are represented as uniform or varying forces or points. In practice, they represent the weights of the building materials used to construct the building (Fig. 1.1), the weights of the people and equipment which will occupy the building, and the forces of nature that the building will be exposed to during its life.

Figs. 1.1a, 1.1b Structural loading diagram of an architectural condition

Material weights are gravity loads which act down (surprise!). People and equipment are primarily gravity loads, but in some instances they may cause forces which act in some other direction. An example is a piece of horizontally moving equipment which suddenly comes to a stop, such as a gantry crane, causing a horizontal force to be induced in the structure. Highway bridges are constantly subjected to this loading condition.

Wind forces are primarily horizontal but can induce vertical forces when blowing over surfaces. Note that wind passing over an airplane wing causes the upward lift that keeps the plane in the air. Similar conditions can be induced in the roof structure of a building.

Earthquakes, by contrast, are wave-like forces which have both horizontal and vertical components; however, the horizontal force component is typically the more destructive of the two, since most structures are designed to be primarily vertical load-carrying systems. Both wind and earthquake loads are discussed in more detail later in this chapter.

The effect of these forces is to induce states of stress and deformation or deflection in the structure. Deflections are often the governing factors in the design of a structural system. Obviously, a structure fails when it collapses; however, excessive deflection which damages finishes or other building components without causing collapse is also defined as a structural failure.

Building codes categorize these loads into two classifications: dead loads and live loads. Dead loads are the permanent loads generated by the constructional system. Live loads are the nonpermanent loads applied to the structure after it is completed. Some loads may be in either category, depending upon their time of application. It is essential to understand the construction sequence of the building, and to design for deflection caused by live loads introduced after the construction is complete. For example, a typically permanent (dead) load such as an HVAC (heating, ventilating, air conditioning) unit should be considered a live load if installed after ceiling finishes are in place, since it would cause deflection of the ceiling/ floor components similar to that created by snow on a roof or human occupancy of a level above. This may occur even if a building component is assumed to be in place prior to finishes. A manufacturing delay, a labor dispute, a delivery problem, or even a design change may be responsible for an out-ofsequence installation which could have serious deflection implications.

An objective of the building codes is to limit the deflection of structural members to the extent that they do not damage the connected nonstructural components or affect the functionality of the building. In the 2003 International Building Code (IBC), as in previous codes, limitations are imposed on deflections due to both dead and live loads (Table 1.1).

Table 1.1 Maximum Allowable Deflection for Structural Membersa

This shouldn't suggest that dead loads don't cause deflection. The dead load deflection of the structure isn't considered in some cases since it is compensated for during the construction process. For example, the ceiling finish, which is (obviously) installed after the horizontal framing is enclosed, is installed “level.” Any dead load deflection which exists in the framing will be hidden by adjusting the finish. The possible exception involves roof construction; consequently, care This shouldn't suggest that dead loads don't cause deflection. The dead load deflection of the structure must be taken to ensure that “flat” roof systems have no water retention areas-ponding-mentioned earlier.