Relationship Of The Ratio Between Longer to Shorter Span

DESIGN OF GLOBE VIEW RESIDENTIAL BUILDING
Introduction
The proposed site is located at Queenhithe and near river Thames and close to Millennium
Bridge. The area contains a residential building known as Globe view that provides a clear view
of River Thames. The total area of the site is approximately 235.1 square meters and the building
consists of two bedrooms.
Construction work and sequences
Construction of the residential building would involve the following;
a. Paper work: this would involve drawing preparation, material estimation cost, cost of
labor and drawing approval from the authorities.
b. Layout mark: The approved drawings would then be marked on the ground with claear
and accurate orientation and dimensions
c. Foundation work: It would involve excavation and compaction of the bottom, reinforced
footing would be laid, and concrete shuttering would be done based on the mentioned
dimensions in the drawing.
d. Footing concrete: The foundation levels would be checked before concrete work, the
concrete would then be poured based on the drawing.
e. Column casting: This would be done through shutter fixing formwork then after the
concrete would be poured into the formwork
f. Wall construction: Walls would be constructed either using wooden, brick or precast
concrete.
g. Roofing: The roof slab would first be poured after the masonry work would be completed
h. Fixing windows and doors: Frames would be fixed during masonry work, thereafter the
panel would be fixed using hinges
i. Electrical and plumbing work: This would be done before applying final finishes
Detailed design
Slab design
In reference to IS 456:2000 the slabs would be designed under limit state
Take fck = 15 N/mm2
Take fy =415 N/m2
Span

a. Shorter span:- Lx = 5.8 m
Longer span:-Ly =7.6 m
b. Check Lx/Ly= 7.6/5.8 =1.3<2 (the slab will be designed as two way slab)
c. Take the overall slab depth be = 120mm and cover depth be 15 mm
Effective depth= Depth -15- ∅/2 =120-15-10/2=100mm
d. The slab is supported on its four sides.
e. Calculation of loads:
Dead load = 25x0.12 m x1m = 3.0KN/m
Live load =2 x 1 = 2.0KN/m
Floor finish = 1x1KN/m
Total load = 6.0 KN/m
f. Calculation of Bending moment : (Based on IS code 456-2000)
Panel types:- Discontinuous two adjacent edges
ax(+) = 0.049 ax(-) = 0.065
ay(+) = 0.035 ay(-) = 0.047
In shorter directions
Positive bending moment at mid-span
Mx(+) = ax(+)wlx2 = 0.049x6x5.82 = 9.9 kN-m
Factored bending moment = 9.9 x 1.5 =14.9 kN-m
Diameter and spacing
Based on sp- 16
Provide a bar of diameter 8 mm at a spacing of 210 mm
Negative bending moment at continuous edge
Mx(-) = ax(-)wlx2 = 0.062x6x5.82 = 13.1 kN-m

Factored bending moment = 13.1 x 1.2 =19.7 kN-m
Longer directions
Positive bending moment at mid-span
My(+) = ay(+)wlx2 = 0.035x6x5.82 = 7.1 kN-m
Factored bending moment = 7.1 x 1.5 =10.7 kN-m
Negative bending moment at continuous edge
My(-) = ay(-)wlx2 = 0.047x6x5.82 = 9.5 kN-m
Factored bending moment = 9.5 x 1.5 =14.2 kN-m
Checking depth
Permissible depth is 100 mm
Mu. limit =0.36 * Xu,max/d * (1 – 0.42* Xu,max/d)fck*bd2
14.86 * 106 = 0.36* Xu,max/d * (1 – 0.42*0.48)*15 *1000*d2
d = 84.7 < 100 mm
Therefore, it’s ok
BEAM DESIGN
Beam member in a building helps in transferring slab load to column and for foundation into the
soil
 Slab span would determine the beam spacing
 Loads that acts on the beam includes; Live load, dead load and wind load
Beam loads
Beam: B1
Shorter span = 5.8 m
Consider the size of the beam = 230 * 405 mm

Height of wall = 3 m
Calculation of loads
Wall load = 0.23 * 19 = 13.1 kN-m
Self-load = 0.23 *0.406 * 25 = 2.3 kN/m
Load of the slab
W = 6 kN
Lx = 5.8
W*Lx/3 = (6 * 5.8)/3 = 11.6 kN/m
Total load = 13.1 + 2.3 + 11.6
= 27.0 kN.m
Design of stirrups
Beam: B1
Va = Vb = (27.0 *5.8)/2
= 78.42 kN
 Normal shear calculation
Tv = Vu/Bd = (1.5 * 71.42 * 103)/(373 *230)
= 1.37
 Permissible shear stress calculations
Tc = percentage of steel
Pt = Ast/Bd * 100
Ast = (2*162 * pi)/4 = 402.12 mm2
Pt = (402.12 * 100)/(230 *373) = 0.60%
Tc = 0.50