The document summarizes the preliminary design of a continuous beam between grid lines B and C with a span of 24'6". It determines the required depth of the beam to meet deflection criteria according to design standards. It then checks ductile detailing criteria for hoop spacing at the beam ends and selects a beam depth of 18" x 18" to satisfy both criteria.

1. CRITICAL BEAM:
Beam bothside continuous:
between horizontal grid lines B and C
Span of the beam: 24’6” (7467.60mm)
PRELIMINARY DESIGN OF BEAM
DEFLECTION CRITERIA:(fromIS456:2000, cl. 23.2.1)
Span/depth = abcde
i) Beam bothside continuous:
a = 26
b = 1 (beam having span < 10m)
c = 0.8 (assuming 2.5% tension steel)
d = 1.25 (assuming 1% compression steel)
e = 0.8 (assuming web width/flangewidth < 0.3)
so, span/depth = 26*1*0.8*1.25*0.8 =20.8(approx.)
and, depth = span/20.8
=7467.6/20.8
=359.01mm
Overalldepth = depth + dia. of bar/2 + clear cover = 359.01+25/2+25
=396.51
Assumedepth of beam as 500mm
DUCTILE DETAILING CRITERIA:(fromIS13920:1993,cl.6.3.5)
The spacing of hoops over a length of 2d at either end of a beam
S < [ deff /4, 8*φ small longitudinal bar] min
• Assume, s =100 mm
• Effective depth of the beam/4 =100 mm
• Effective depth of the beam =400mm
• Overalldepth of the beam = 400+25/2+25=437.5
Assumedepth of beam as 450mm(18”). And width 450mm