Effect of U-Turn in Reinforced Concrete Dog-Legged Stair Slabs
Reinforced concrete stair slabs with mid landings i.e.
Dog-legged shaped are conventionally designed as per specifications
of standard codes of practices which guide about the effective span
according to the varying support conditions. Presently, the behavior
of such slabs has been investigated using Finite Element method. A
single flight stair slab with landings on both sides and supported at
ends on wall, and a multi flight stair slab with landings and six
different support arrangements have been analyzed. The results
obtained for stresses, strains and deflections are used to describe the
behavior of such stair slabs, including locations of critical moments
and deflections. Values of critical moments obtained by F.E. analysis
have also have been compared with that obtained from conventional
analysis. Analytical results show that the moments are also critical
near the kinks i.e. junction of mid-landing and inclined waist slab.
This change in the behavior of dog-legged stair slab may be due to
continuity of the material in transverse direction in two landings
adjoining the waist slab, hence additional stiffness achieved. This
change in the behavior is generally not taken care of in conventional
method of design.
[1] Building Code Requirement for Structural Concrete (ACI-318-05),
American Concrete Institute, 2005.
[2] British Standard: Structural Use of Concrete Part-I (Code of Practice for
Design and Construction), BS 8110 Part 1: 1985, British Standards
Institution, May, 1989.
[3] Indian Standard: Plain and Reinforced Concrete- Code of practice (IS-
456: 2000) Bureau of Indian Standards, New Delhi, July, 2000.
[4] I. Ahmed, A. Muqtadir and S. Ahmed, "A Design Basis for Stair Slabs
Supported at Landing Level", Journal of Structural Engineering, ASCE,
Vol. 121(7), July 1995, pp.1051-1057.
[5] I. Ahmed, A. Muqtadir and S. Ahmed, "Design Provisions for Stair
Slabs in the Bangladesh Building Code", Journal of Structural
Engineering, ASCE, Vol. 122(3), March 1996, pp.262-266.
[6] M. Aslam, "Analysis of Two Flight Staircase by Finite Element
Method", M. Tech. (Civil Engg.) Dissertation, Department of Civil
Engineering, Aligarh Muslim University, Aligarh, India, 2004.
[7] M. Y. Yahya, "An Analysis of the effect of Staircase Intermediate
Landing Floor on the Evaluation Time", Journal Alam Bina, Jilid 12 :
No.3, 2008.
[1] Building Code Requirement for Structural Concrete (ACI-318-05),
American Concrete Institute, 2005.
[2] British Standard: Structural Use of Concrete Part-I (Code of Practice for
Design and Construction), BS 8110 Part 1: 1985, British Standards
Institution, May, 1989.
[3] Indian Standard: Plain and Reinforced Concrete- Code of practice (IS-
456: 2000) Bureau of Indian Standards, New Delhi, July, 2000.
[4] I. Ahmed, A. Muqtadir and S. Ahmed, "A Design Basis for Stair Slabs
Supported at Landing Level", Journal of Structural Engineering, ASCE,
Vol. 121(7), July 1995, pp.1051-1057.
[5] I. Ahmed, A. Muqtadir and S. Ahmed, "Design Provisions for Stair
Slabs in the Bangladesh Building Code", Journal of Structural
Engineering, ASCE, Vol. 122(3), March 1996, pp.262-266.
[6] M. Aslam, "Analysis of Two Flight Staircase by Finite Element
Method", M. Tech. (Civil Engg.) Dissertation, Department of Civil
Engineering, Aligarh Muslim University, Aligarh, India, 2004.
[7] M. Y. Yahya, "An Analysis of the effect of Staircase Intermediate
Landing Floor on the Evaluation Time", Journal Alam Bina, Jilid 12 :
No.3, 2008.
@article{"International Journal of Architectural, Civil and Construction Sciences:52406", author = "Abdul Baqi and Zaid Mohammad", title = "Effect of U-Turn in Reinforced Concrete Dog-Legged Stair Slabs", abstract = "Reinforced concrete stair slabs with mid landings i.e.
Dog-legged shaped are conventionally designed as per specifications
of standard codes of practices which guide about the effective span
according to the varying support conditions. Presently, the behavior
of such slabs has been investigated using Finite Element method. A
single flight stair slab with landings on both sides and supported at
ends on wall, and a multi flight stair slab with landings and six
different support arrangements have been analyzed. The results
obtained for stresses, strains and deflections are used to describe the
behavior of such stair slabs, including locations of critical moments
and deflections. Values of critical moments obtained by F.E. analysis
have also have been compared with that obtained from conventional
analysis. Analytical results show that the moments are also critical
near the kinks i.e. junction of mid-landing and inclined waist slab.
This change in the behavior of dog-legged stair slab may be due to
continuity of the material in transverse direction in two landings
adjoining the waist slab, hence additional stiffness achieved. This
change in the behavior is generally not taken care of in conventional
method of design.", keywords = "Dog-legged, Stair slab, F.E. Analysis, Landing, Reinforced concrete.", volume = "7", number = "6", pages = "433-6", }