CONTENTS PART 1. WATER TANKS 1. BEAMS CURVED IN PLAN 1.1.Introduction : Torsionalmomentsin beams 1 1.2.Circular beam supported symmetrically 4 1.3.Semicircular beam simply supported on three equally spaced columns 11 1.4. Curved beam simply supported at ends and continuous over two equally spaced intermediate supports 17 1.5.Curved beam fixed at ends 20 1.6.Semi-circular beam with slab 26 1.7.Torsion factor 29 1.8.Stresses due to torsion in concrete beams 33 1.9.Indian standard Code for design for torsion (IS : 456-1978)42 Problems 56 2. DOMES 2.1.Introduction 57 2.2.Nature of stresses in spherical domes 57 2.3.Analysis of spherical domes 59 2.4.Stresses due to wind load 65 2.5.Design of R.C. domes 65 2.6.Conical domes 72 Problems 76 3. CIRCULAR AND INTZE TANKS 3.1. Introduction 77 3.2.General design requirements according to Indian Standard Code of Practice (IS : 3370, Part II, 1965) 78 3.3.Joints in water tanks 83 3.4.Circular tank with rigid joint between floor and wall 86 3.5.I.S. Code method and other methods for cylindrical tanks 95 3.6.Design of flat base slab for elevated circular tanks 126 3.7. Circular tank with domed bottom and roof 139 3.8. Intze tank 160 3.9. Effects of continuity 166 3.10. Design of tank supporting towers 166 3.11. Design of foundations 180 Problems 230 4. RECTANGULAR TANKS 4.1 Introduction 231 4.2 Approximate method 232 4.3. Exact method241 Problems 260 5. UNDERGROUND TANKS 5.1.Introduction261 5.2. Earth pressure on tank walls 261 5.3. Uplift pressure on the floor of the tank 264 5.4. Design of rectangular tank 264 Problems 278 PART 2. PIPES, SILOS & CHIMNEYS CHAPTER 6. REINFORCED CONCRETE PIPES 6.1. Loads on pipes 281 6.2 Stresses due to hydrostatic pressure282 6.3.Stresses due to self weight 283 6.4.Stresses due to weightof water inside 286 6.5 Stresses due to earthfill over haunches 287 6.6. Stresses due to uniformly distributed load on top 288 6.7.Stresses due to uniform pressure from sides 288 6.8.Stresses due to triangularly distributed load 289 6.9.Stresses due to point load on crown 290 6.10. Stresses due to over-burden and external loads 291 Problems 300 7. BUNKERS AND SILOS 7.1.Introduction 301 7.2. Janssen's theory 302 7.3. Airy's theory 306 7.4. Bunkers .. 311 7.5. Hopper bottom 313 7.6. Indian Standard on design of bins 316 Problems 340 8. CHIMNEYS 8.1.Introduction341 8.2. Wind pressure 341 8.3. Stresses in chimney shaft due to self- weight and wind 342 8.4.Stresses in horizontal reinforcement due to wind shear 347 8.5.Stresses due to temperature difference 348 8.6 Combined effect of self load, wind and temperature 350 8.7.Temperature stresses in horizontal reinforcement 355 8.8.Design of R.C. chimney356 Problems 366 PART 3. CONCRETE FRAMES 9. PORTAL FRAMES 9.1. Introduction 369 9.2.Analysis of portal frames 370 9.3.Design of rectangular portal frame with vertical loads 370 9.4.Design of hinge at the base385 Problems 386 10. BUILDING FRAMES 10.1 Introduction387 10.2. Substitute frames 388 10.3. Analysis for vertical loads 391 10.4. Methods of computing B.M. 394 10.5. Analysis of frames subjected to horizontal forces407 10.6. Portal method 408 10.7. Cantilever method 410 10.8. Factor method 419 Problems 433 PART 4. CONCRETE BRIDGES 11. AQUEDUCTS AND BOX CULVERTS 11.1. Aqueducts and syphon aqueducts 437 11.2. Design of an aqueduct 438 11.3. Box culvert 444 11.4. Design of box culvert 444 Problems 462 12. CONCRETE BRIDGES 12.1. Introduction : Various types of bridges 463 12.2. Selection of type of bridge and economic span length 467 12.3. Types of loads, forces and stresses 468 12.4. Live load 468 12;5. Impact effect 476 12.6. Wind load 478 12.7. Longitudinal forces 479 12.8. Lateral loads 481 12.9. Centrifugal force 481 12.10. Width of roadway and footway 482 12.11. General design requirements 482 12.12. Solid slab bridges 487 12.13. Deck girder bridges 505 12.14. B.M. in slab supported on four edges 507 12.15. Distribution of live loads on longitudinal beams 522 12.16. Method of distribution coefficients 524 12.17. Courbon's method 547 12.18. Design of a T-beam bridge 549 12.19. Balanced cantilever bridge 613 Problems 657 PART 5. LIMIT STATE METHOD 13. DESIGN CONCEPTS 13.1. Methods of design 661 13.2. Safety and serviceability requirements (IS : 456-1978) 663 133. Characteristic and design values and partial safety factors 664 Problems666 14. SINGLY REINFORCED SECTIONS 14.1. Limit state of collapse in flexure667 14.2. Stress strain relationship for concrete 669 143. Stress-strain relationship for steel 669 14.4. Stress block parameters 672 14.5. Design stress block parameters (IS : 456-1978) 675 14.6. Singly reinforced rectangular beams 677 14.7. Procedure for finding moment of resistance 679 14.8. Design of rectangular beam section 682 Problems692 15. DOUBLY REINFORCED SECTIONS 15.1. Necessity 693 15.2. Stress block and KA. 693 153. Determination of moment of resistance 695 15.4. Design of a doubly reinforced section 697 Problems 704 16. T AND L-BEAMS 16.1. Introduction 705 16.2. Stress block and N.A. 706 16.3. Moment of resistance when xu<Df 707 16.4. Moment of resistance when N.A. falls in the web 708 16.5. IS Code procedure for finding moment of resistance (IS : 456-1978) 714 16.6. Design of T-beam 717 16.7. Doubly reinforced T-beams 727 Problems 738 17. SHEAR, BOND AND TORSION 17.1. Limit state of collapse : Shear739 17.2. Development length 746 17.3. Limit state of collapse : Torsion 748 Problems752 18. DESIGN OF BEAMS AND SLABS 18.1. Design of beams 753 18.2. Design of cantilever 760 18.3. Design of doubly reinforced beam 764 18.4. Design of one way slab 769 18.5. Design of one way continuous slab 775 18.6. Design of T-beam roof 785 Problems 785 19. AXIALLY LOADED COLUMNS 19.1. Limit state of collapse : Compression 787 19.2. Shortcolumns 789 193. Short axially loaded members in axial compression789 19.4. Short axially loaded columns with minimum eccentricity 790 19.5. Design charts 791 19.6. Compression members with helical reinforcement 794 19.7. Design specifications (IS : 456-1978) 794 Problems 806 20. COLUMNS WITH UNlAXIAL AND BIAXIAL BENDING 20.1. Introduction 807 20.2. Combined axial load and uniaxial bending 807 20.3. Construction of interaction curves for column design 810 20.4. Short columns subjected to axial load and biaxial bending 829 Problems 835 21. DESIGN OF STAIR CASES 21.1. General notes on design of stairs 837 21.2Design of stairs spanning horizontally 841 21.3. Design of dog-legged stair 843 21.4. Design of stairs with quarter space landing 846 Problems 850 22. TWO-WAY SLABS 22.1. Introduction851 22.2. Simply supported slab with corners free to lift (I.S. Code method) 852 22.3. Restrained slabs (I.S. Code method) .. 859 Problems .. 868 CHAPTER 23. CIRCULAR SLABS 23.1. Introduction869 23.2 Slab freely supported at edges and carrying U.D.L. 870 23.3. Slabs fixed at edges and carrying U.D.L. 871 23.4. Slab simply supported at the edges with load w uniformly distributed along the circumference of a concentric circle 872 23.5. Slab simply supported at edges, with U.D.L. inside a concentric circle 873 Problems 882 24. YIELD LINE THEORY AND DESIGN OF SLABS 24.1. Introduction 883 24.2. Yield jine patterns 884 24.3. Moment capacity along an yield line 888 24.4. Ultimate load on slabs 889 24.5. Analysis by virtual work method 890 24.6. Analysis by equilibrium method902 Problem913 25. FOUNDATIONS 25.1. Indian Standard Code Recommendations for design of footings (IS: 456-1978) 915 25.2. Isolated footing of uniform depth 920 25.3. Isolated sloped footing 925 Problems 929 PART 6. PRESTRESSED CONCRETE & MISCELLANEOUS TOPICS 26. PRESTRESSED CONCRETE 26.1. Introduction933 26.2. Basic concepts 935 26.3. Classification and types of prestressing 952 26.4. prestressing systems : End anchorages 956 26.5. Losses of prestress 971 26.6. Computation of elongation of tendons 984 26.7. Properties of materials 995 26.8. Merits and demerits Sf prestressed concrete . 1002 26.9. Basic assumptions 1003 26.10. Analysis of beams for flexure 1003 26.11. Kern distances and efficiency of section 1009 26.12. Design of sections for flexure :Magnet's method 1015 26.13. Rectangular section 1025 26.14. I-Section 1029 26.15. Alternative design procedure 1044 26.16. Shear and diagonal tension 1050 26.17. Stresses at anchorage 1055 26.18. Indian Standard Code recommendations (IS : 1343-1980) 1060 26.19. Procedure for limit state design1084 Problems 1101 27. SHRINKAGE AND CREEP 27.1. Introduction 1103 27.2. Shrinkage of concrete 1103 27.3. Shrinkage stresses in symmetrically reinforced sections 1107 27.4. Shrinkage stresses in singly reinforced beams1109 27.5. Instantaneous and repeated loading on concrete1112 27.6. Sustained loading : Creep 1114 27.7 Factors affecting creep 1116 27.8. Effect of creep on Ec and m 1117 27.9 Effect of shrinkage and creep in columns1118 27.10 Effect of shrinkage and creep in oeams 1120 APPENDIX-A.B.M. and S.F. coefficients 1123 APPENDIX-B. Properties of materials and concrete1127 APPENDIX-C. Reinforcement 1134 APPENDIX-D. Loading 1137