Advanced Reinforced Concrete Design

371 Pages·2016·16.093 MB·English

by  N.K. Raju

- - —- ■ —. —X -------------------------------------- -
• \ I | ’ # i^?.y \ 4 i«e v fl I J
; SbJ? ,rJ j^-p
.. C2222JI-•
pB^x i
JJ-zixjJ kJ J J
(IS : 456-2000)
2nd
Edition
• •
N. KRISHNA RAJU
Preface
The extensive use of reinforced concrete for a variety of structural members
has necessitated a proper understanding of the design in structural concrete
members by the structural engineers. The wide spread use of reinforced con­
crete is the natural outcome of the rapid development in the theory and
design procedures with the introduction of the philosophy of limit state
design.
The book presents the design of a variety of reinforced concrete structures
like Continuous beams, Portal frames, Silos, Bunkers, Chimneys, Shells
Overhead Water tanks, Virendeel girders, Trusses, Deep beams, Box culverts,
Folded plates, Hyperbolic cooling towers, Curved girders, Poles, Pipes and
Bridge deek systems. The design of these advanced reinforced concrete struc­
tures conform to the revised Indian Standard Code IS :456-1978 and S.I.
units have been adopted for all the design examples. The topics covered are
intended to meet the requirements of graduate and post graduate curicula of
most of the engineering institutions in India. The book is primarily design
oriented with more emphasis on types of design with minimum extent of
theory, presented wherever required for application in design. The various
design steps are identified and provided in a logical sequence.
The book is extensively illustrated with working drawings showing the
reinforcement details. The examples for practice provided at the end of
each chapter is intended to help the students preparing for university
examinations.
The references provided at the end of the book have been extensively used
in the preparation of the text and are gratefully acknowledged. The author
is grateful to his wife, Pramila and daughters Sarvamangala and Amrutha
for extending their fullest co-operation in the preparation of the type script.
Finally the author welcomes .constructive criticisms and suggestions which
will immensely help in updating the contents of the book.
Bangalore N. KRISHNA RAJU
January, 1986
© N. KRISHNA RAJU
First Published ; 1986
First Reprint : 1988
All rights reserved. No part of this book may be
reproduced or transmitted without the prior and written
permission from the author and the publisher.
Distributors:
College Book Store
1701-2, Nai Sarak, Delhi-110006
Published by Satish Kumar Jain for CBS Publishers & Distributors
485, Jain Bhawan, Bhola Nath Nagar, Shahdra, Delhi-110032
Printed at Nazia Printers, Lal Kuan, Delhi-110006.
Contents
Preface v
List of symbols xiii
1. Continuous Beams I
1.1 Introduction 1
1.2 Effective span 1
1.3 Span/depth ratio 2
1.4 Bending moments and shear forces 2
1.5 Design Example 4
1.6 Design Example 6
1.7 Examples for Practice 9 ’
2. Bunkers and Silos 11
2.1 Introduction 11
2.2 Difference between bunker and silo. 11
2.3 Design of square or rectangular bunkers 13
2.4 Design of circular bunkers 17
2.5 Design Example 17
2.6 Design Example 21
2.7 Design of battery of bunkers 26
2.8 Design of silos 27
2.9 Silos for storage of cement 33
2.10 Design Example 35
2.11 Design Example 39
2.12 Design Example 40
2.13 Examples for Practice 42
3. Chimneys 44
3.1 General 44
3.2 Parts of Chimney 44
3.3 Design Factors 45
3.4 Stresses in R.C. Shafts due to self weight and wind loads 46

viii Contents
3.5 Stresses in Horizontal Reinforcement due to shear force 49
3.6 Stresses due to Temperature difference 50
3.7 Design Example 57
3.8 Design Example 57
3.9 Design Example 64
3.10 Design of Reinforcements in Chimneys using Charts 66
3.11 Analysis and design of R.C. Chimneys subjected to Dynamic loads 67
3.12 Examples for Practice 67
4. Curved Beams 69
4.1 General 69
4.2 Analysis of Bending and Torsional moments in circular beams 69
4.3 Moments in semicircular beams supported on thr columns 71
4.4 Design Example 72
4.5 Design Example 74
4.6 Examples for Practice 78
5. Towers 79
5.1 General 79
5.2 Design Principles 79
5.3 Computation of moments due to wind loads 80
5.4 Wind load Analysis of a Tower with circular group of columns 85
5.5 Design Example 87
5.6 Design Example 90
5.7 Examples for Practice 93
6. Elevated Water Tanks 95
6.1 Types of overhead water tanks 95
6.2 Intz type tank 95
6.3 Design example of Intz type water tank 101
6.4 Conical or Funnel shaped tank 115
6.5 Design Example of Funnel shaped over head Tank 117
6.6 Examples for Practice 128
7. Box—Culverts 131
7.1 General Aspects 131
7.2 Design Loads 131
7.3 Design of Critical sections 133
7.4 Design Example 134
7.5 Examples for Practice 40
8. Portal Frames 141
8.1 Introduction 141
8.2 Analysis and Design of Portal Frames 141
8.3 Design Example 143
8.4 Design Example 149
8.5 Examples for Practice 157
9. Multistorey Building Frames 158
9.1 Analysis of Multistorey Frames 158
9.2 Method of substitute Frames 158
Contents ix
9.3 Design Example 160
9.4 Bending moments in columns 168
9.5 Analysis of Multistorey frames subjected to Horizontal forces 169
9.6 Design Example 173
9.7 Examples for Practice 175
10. Shells 176
10.1 Introduction 176
10.2 Shell Terminology 176
10.3 Classification of shells 181
10.4 General specification of shells 181
10.5 Analysis of shells 184
10.6 Examples for Practice 203
11. Hyperbolic Paraboloid Shells 205
11.1 General Features 205
11.2 Geometry of Hyper shell 205
11.3 Analysis of Membrane forces 206
11.4 Inverted Umbrell roof 207
11.5 Design Example 208
11.6 Design Example 210
11.7 Types of hyperbolic Paraboloid Roofs 214
11.8 Examples for Practice 215
12. Hyperbolic Cooling Towers 217
12.1 General Aspects 217
12.2 Hyperboloid of Revolution 217
12.3 Analysis of Membrane forces 218
12.4 Design Example 222
12.5 Analysis of Hyperbolic Cooling Towers for wind load 225
12.6 Design Example 229
12.7 Examples for Practice 230
13. Folded Plates 231
13.1 General Features 231
13.2 Analysis of Folded plates 231
13.3 Structural behaviour of Folded plates 233
13.4 Whituey’s Method 235
13.5 Simpson’s Method 235
13.6 Iteration Method 236
13.7 Beam Method 237
13.8 Winter and Pei’s Method 237
13.9 Equation of three shears 237
13.10 Design Example 239
13.11 Stress Conditions in Hipped plates 240
13.12 Design Example 241
13.13 Design Example 245
13.14 Design Example 253
13.15 Examples for Practice 256
'14. Grid or Coffered Floors 258
14.1 General Features 258
x Contents
14. 2 Analysis of Grid Floors 258
14. 3 Design Example 262
14. 4 Examples for Practice 269
IS. Virendeel Girders 271
15.1 General Features 271
15.2 Analysis of Virendeel Girdders 271
15.3 Design Example 273
15.4 Design Example 275
15.5 Design of Members of Virendeel Girder 275
15.6 Design Example 277
15.7 Examples for Practice 280
16. Trusses 281
16.1 General Features 281
16.2 Dimensions of Trusses 281
16.3 Material Requirements 282
16.4 Constructional Features 283
16.5 Analysis of Trusses 284
16.6 Design Example 285
16.7 Examples for Practice 291
17. Poles 292
17.1 General Features 292
17.2 Classification of Poles 293
17.3 Design Features 293
17.4 Design Example 294
17.5 Examples for practice 297
18. Deep Beams 299
18.1 General Features 299
18.2 Parameters Influencing design 299
18.3 Flexural Bending Stresses 300
18.4 Shear Stresses in Deep Beams 306
18.5 I.S. Code Provisions 306
18.6 Design Example 308
18.7 Design Example 311
18.8 Design Example 312
18.9 Examples for Practice 313
19. Pipes 314
19.1 General Aspects 314
19.2 Classification of R.C.C. Pipes 314
19.3 Design Principles 314
19.4 Reinforcements in Pipes 316
19.5 Tests on Pipes 316
19.6 Design Example 317
19.7 Design of Non Pressure R.C.C. Pipes for Culverts 318
19.8 Design Example 321
19.9 Examples for Practice 324
Contents xi
20. Bridge Deck Systems 325
20.1 General Types 325
20.2 Analysis and Design of slab Decks 325
20.3 Analysis and Design of Tee beam and slab decks 334
20.4 Design Example 335
20.5 Design Example 339
20.9 Examples for Practice 351
Appendix 1 355
Appendix 2 356
References 357