Book contents
- Frontmatter
- Contents
- Preface
- Acknowledgements
- Notation
- Acknowledgements for tables and diagrams
- Acronyms and abbreviations
- Part I Reinforced concrete
- 1 Introduction
- 2 Design properties of materials
- 3 Ultimate strength analysis and design for bending
- 4 Deflection of beams and crack control
- 5 Ultimate strength design for shear
- 6 Ultimate strength design for torsion
- 7 Bond and stress development
- 8 Slabs
- 9 Columns
- 10 Walls
- 11 Footings, pile caps and retaining walls
- Part II Prestressed concrete
- Appendix A Elastic neutral axis
- Appendix B Critical shear perimeter
- Appendix C Development of an integrated package for design of reinforced concrete flat plates on personal computer
- Appendix D Strut-and-tie modelling of concrete structures
- Appendix E Australian Standard precast prestressed concrete bridge girder sections
- References
- Index
9 - Columns
from Part I - Reinforced concrete
- Frontmatter
- Contents
- Preface
- Acknowledgements
- Notation
- Acknowledgements for tables and diagrams
- Acronyms and abbreviations
- Part I Reinforced concrete
- 1 Introduction
- 2 Design properties of materials
- 3 Ultimate strength analysis and design for bending
- 4 Deflection of beams and crack control
- 5 Ultimate strength design for shear
- 6 Ultimate strength design for torsion
- 7 Bond and stress development
- 8 Slabs
- 9 Columns
- 10 Walls
- 11 Footings, pile caps and retaining walls
- Part II Prestressed concrete
- Appendix A Elastic neutral axis
- Appendix B Critical shear perimeter
- Appendix C Development of an integrated package for design of reinforced concrete flat plates on personal computer
- Appendix D Strut-and-tie modelling of concrete structures
- Appendix E Australian Standard precast prestressed concrete bridge girder sections
- References
- Index
Summary
Introduction
Columns exist in all conventional building structures. Whereas beams, slabs or even trusses may be used to span the floors, columns carry loads vertically, floor by floor, down to the foundations. Even in specialised systems such as shear wall, shear-core and framed-tube structures, columns are used to support parts of the floor areas.
Figure 9.1(1)a shows a portion of a three-dimensional building frame. For the purposes of discussion on the role of columns, the frame may be taken as representative of other popular building systems, such as multistorey flat slabs, as well as beam/slab and column structures. At each level, the floor spans in both the x and z directions. As a result, bending occurs in both the x-y and y-z planes. Thus, for a typical column AB, the forces acting at the top end or joint A, include
(i) N, the axial force equal to the portion of the vertical load (from the floor immediately above) to be carried by column AB plus the axial load transmitted by the column above (i.e. column CA)
(ii) Mx, the bending moment about the z-axis
(iii) Mz, the bending moment about the x-axis.
These are illustrated in Figure 9.1(1)b. Note that a similar set of end forces also exists at the bottom end (joint B).
These three-dimensional forces are statically indeterminate and computer-based structural analysis procedures are normally relied on to determine their values.
- Type
- Chapter
- Information
- Reinforced and Prestressed ConcreteAnalysis and Design with Emphasis on Application of AS3600-2009, pp. 210 - 244Publisher: Cambridge University PressPrint publication year: 2010