2-Structural-Design 2012 Strip Method
2-Structural-Design 2012 Strip Method
2-Structural-Design 2012 Strip Method
Slabs
Dr.-Ing. Girma Zerayohannes
Dr.-Ing. Adil Zekaria
Chapter 2- Strip Method for Slabs
• 2.1 Introduction
• Different methods of analysis are allowed by
ES EN 1995, 2015
• One of these is plastic methods
• Strip method is a plastic method of analysis
mx m y mxy
2 2 2
2 w
x 2
y 2
xy
w
x 2
y 2
my
2
(1 k ) w
y 2
Figure 2
Dr.-Ing. Girma Zerayohannes 19
Chapter 2- Strip Method for Slabs
• The load on all strips in each direction is thus
w/2 ( with k=0.5), as illustrated by the load
dispersion arrows
• This gives maximum design moments mx = my
= wa2/16, implying a constant curvature for all
strips in the x-direction at mid-span
corresponding to a constant moment wa2/16
across the width of the slab (see fig. 2)
Figure 3
Dr.-Ing. Girma Zerayohannes 23
Chapter 2- Strip Method for Slabs
• Here the regions of different load dispersion
separated by the dash-doted discontinuity
lines follow the diagonals, and all of the load
on any region is carried in the direction giving
the shortest distance to the nearest support.
• k=0 or 1 in the different regions
Figure 4
Dr.-Ing. Girma Zerayohannes 28
Chapter 2- Strip Method for Slabs
• Two different strip loadings are now identified,
strip along A-A and along B-B.
• This design leads to practical arrangement,
one with constant spacing through the center
strip of width a/2 and a wider spacing through
the outer strips, where the elastic curvatures
and moments are known to be less.
A A
Figure 7
Figure 8