IE DESIGN ASSIGNMENT
DESIGN OF EARTHQUAKE RESISATNT
BUILDING
BY
JEETU RANA(roll no 39)
HEMANTH KUMAR(roll no 36)
ABSTRACT
In
this project work, an attempt has been made to plan and design a G+4 storied shopping
complex building. This project work involves planning, analysis, designs,
drawings and estimation of a typical multistoried building.
The salient features of the G+4
storied building are as given below the basement floor is 1.20m above the
existing ground level. The shopping complex consists of G+4 floors with 3.60m
ceiling height. The carpet area available in each floor is 1220sq.m.
This shopping complex having all
facilities under one roof, designed with shops, Super market, Food court, Net
point, Gym, Table tennis court, Coffee shop with ample car parking etc, with very good water supply and sanitary
arrangements.
The planned five storey commercial building frame
in modeled in STAAD Pro.Various load combinations are included in the frame analysis
and the lateral loads are calculated by seismic coefficient method for the
earthquake zone III with response reduction factor 3. The amount of concrete
and steel required along with the total cost of the building is calculated.
The
structural design has been manually done. The estimate of the building is
prepared on the basis of plinth area rate. Necessary structural drawings are
enclosed at appropriate places.
INTRODUCTION
1.1. SCOPE &
IMPORTANCE:
Shopping
and Entertainment is an important for each and every one. But they have short
of time, so they need a shopping complex under one roof to save the valuable
time.
1.2. LOCATION:
We
have decided to choose the site for the construction of shopping complex at Vadapalani
in Chennai city.
The
site accommodates the following special feature.
Ø Land is available in the centre of city.
Ø The site is located in main road.
Ø 24 hour transportation facilities available.
3.2. ANALYSIS:
3.2.1. MATERIAL:
Grade of reinforcement :
Fe415
Grade of concrete :
M25
Density of concrete :
2500Kg/m3
3.2.2. LOADING:
Dead load:
Partition wall and
other external walls, floor finish etc., as per the provisions of IS: 875-1987(part
I)
Superimposed load:
As per the provisions
of IS: 875-1987(part II)
For Commercial
Buildings (AL) = 4.00 KN/m2
Seismic load
Dead load + part of live load = DL+0.5LL
3.2.3. CODES:
Concrete design : IS: 456-2000
Steel design : IS: 800-1984
3.2.4. PARTIAL SAFETY
FACTORS:
Load factors:
For dead load = 1.50
For live load = 1.50
The above partial safety factors are taken from IS: 456-2000
Material safety factor:
For reinforcement steel = 1.15
For concrete = 1.50
3.2.5. LOAD CALCULATION:
Dead load:
At any floor level except ground floor (per m width)
Load from slab = 0.15 x 23.5 = 3.525 KN/m2 (assuming 150mm
thickness)
Partitions (G.F) = 0.23 x 4.20 x 20 =19.32 KN/m
Partitions (F.F TO F.F) = 0.23 x 3.00 x 20 =13.80 KN/m
Partitions (Terrace floor) = 0.23 x 1.00 x 20 =4.60 KN/m
Floor finishes = 1.00 KN/m2
Floor finishes (Terrace floor) = 2.00 KN/m2
B) Live load
For Commercial Buildings = 4.00
KN/m2
C) Seismic load
Dead load + part of live load = DL+0.5LL
3.2.6. ANALYSIS ABOUT
STAAD Pro:
4.2. LIMIT STATE METHOD:
Limit
state of Design is a further improvement of ultimate load design in the limit
state methods a structure is designed to with stand all loads like to act on it
in the duration of its life span and also to satisfy the service requirements
like deflection and limitation of crack width, limit means an acceptable limit,
for the safety and serviceability requirements before anything can occur.
The
design provides a condition that the structure will not become unfit for use
for which it is meant or in other words the structure will not reach a limit
state.
The
entire limit state that are relevant are
considered in the design to ensure an adequate degree of safety and
serviceability, the structure in general shall be designed on the basis of the
most critical state and shall also be checked for other limit states.
4.2.1. LIMIT STATE OF COLLAPSE :
The design on limit state of collapse provides the
necessary safety of the structure against partial or total collapse of the
structure.
4.2.2. LIMIT STATE OF SERVICEABILITY :
This limit state is
introduced to prevent objectionable deflection and cracking.
4.2.3. CHARACTERISTICS
STRENGTH OF CONCRETE:
Grade
|
M15
|
M20
|
M25
|
M30
|
M35
|
M40
|
Fck
N/mm2
|
15
|
20
|
25
|
30
|
35
|
40
|
4.2.4. CHARACTERISTICS
STRENGTH OF STEEL:
Grade
|
Fe250
|
Fe415
|
Fe500
|
fyN/mm2
|
250
|
415
|
500
|
4.2.5. CHARACTERISTIC LOADS:
Characteristics load means the value of the
load, which has a 95 percent probability of not being exceeded during the life
of the structure.
Characteristics load is the weight
of the structure itself. Characteristic live load and wind load are taken as
per IS875-1964 characteristic seismic loads are taken as per 1873-1975.
4.2.6. OBJECTS OF LIMIT STATE
DESIGN:
The object of limit state design is the
guarantee adequate safety consistent with economy against the structure being
rendered unfit for service due to cracking, deflection, failure and such other
cases. A limit sate corresponds to each of the states in which the structure
becomes unfit.
5. DESIGN OF BEAM
5.1. DESIGN OF BEAMS BY
MANUAL (Beam No: 303):
Step - 1
Width of Beam = 300 mm
Over all depth of Beam = 600m
Thickness of slab, Df = 150mm
Breadth of web, bw = 300mm
Concrete grade = M25
Steel grade = Fe415
Step – 2:
Bending moment and shear force
Negative moment @ interior support
= 170.806 kNm
Positive moment @ centre of span = 367.60
kNm
Maximum shear force at its support, Vu =
224.952 kN
Limiting moment of Resistance
Mulimit = 0.138fck
bd2
= 0.138 x25x300x5502
Mulimit = 313.088
kNm
Mu
limit < Mumax
Hence the section is designed for doubly reinforced.
Mu2 = 367.60-313.088
=
54.512kN.m
Ast
calculation:
Mu = 0.87
fy Ast d (1- (fyAst/fckbd))
313.088x106 =
0.87 x 415 x Ast x 550
(1- (415 x
Ast
/ 25x300x550))
313.088 x 106 =
198577.5 Ast – 19.978
Ast2
Ast1 = 1965.19 mm2
Use 25mm dia bars
No of bars required = Ast / ast = 1965.19
/ ((π/4) x 252)
= 4.00 Say 4 nos
Main reinforcement (excess reinforcement Positive)
Mu1 = 0.87
fyAst2(d-d’)
54.512x 106
= 0.87 x 415 x Ast2 x
(550-50)
54.512 x 106
= 180525 Ast2
Ast =
301.97 mm2
No of bars required = Ast / ast
=
301.96 / ((π/4) x 252)
= 0.62 Say 1 nos
Provide 5 nos of bars #25 at the Bottom tension face
at centre of span section.
Asc calculation:-
Main reinforcement (Negative)
Mu = fsc
Asc (d-d’)
d’/d = 50/550 =0.09
fsc = 353.40N/m2
170.806x 106
= 353.40 x Asc x
(550-50)
Ast = 966.64 mm2
No of bars required = Ast / ast = 966.64 / ((π/4) x 252)
= 1.97 Say 2 nos
Provide 2 Nos of bars #25 at the top tension face near support
6. DESIGN OF COLUMN
6.1 GENERAL
From
the STAAD Pro Analysis done we obtain the maximum positive moment, maximum
negative moment and maximum shear force from these the beams are designed
manually.
Maximum moments and shear forces
Beam node Env Fx
Fy Fz Mx
My
Mz
kN kN kN kNm kNm kNm
231 86
+ve 3513.2 94.90 100.4 1.33 277.73 233.99
-ve
-63.88 -104.1 -114.8 -1.32 -248.0 -253.11
6.2. DESIGN OF COLUMNS BY MANUAL
(Beam No: 231):
Beam
size = 450 x 450mm
Concrete
grade = M25
Steel
grade = Fe415
Factored
load Puz = 2477.56kN
Factored
Moment Muz = 11.747kN.m
Muy = 262.42kN.m
Moments due to minimum eccentricity are less than the
values given above
Reinforcement is distributed equally on four sides
As a first trail assume the reinforcement P = 3.75
P/fck
= 3.75/25 = 0.15
Uniaxial moment capacity of the section about XX and YY axis
Effective
cover d’ = cover +dia of
rod/2
= 40+25/2 = 52.5mm
Effective
depth d = 450-25-(25/2)
d = 412.50mm
D = 450mm
d’/D = 52.5/450
=
0.1167
Check for d’/D 0.15 will be used
Pu/fck
bd = 2477.56 x 103/ (25 x 450 x
450)
= 0.49
Referring to chart45
Mu/
fck bd2 = 0.135
Mux1
= Muy1 = 0.135
x 25 x 450 x 4502
= 307.55kN.m
7. DESIGN OF FOUNDATION:
7.1 GENERAL
The
outer Column footings are designed as Isolated footings where as the Inner
column footings are designed as Combined footings. In these combined footings
the two adjacent columns are combined in the Z axis direction. From the STAAD
Pro analysis done we obtain the Axial
load for the designing of footing
7.2 Design of combined
footing: - (Node No: 89 and 91)
Axial load
Pu2 = 3938.35 say 4000 kN
To find Shear
force,
= 7.2m2
Thickness of
footing required against bending moments:-
حcu = Ks. حc
= 0.5
+ (0.45 /0.45)
Check for Effective depth required against two way
shear (or) punching shear. The critical section of two way shear is taken at a
distance of d/2 around form the pedestal
Bearing capacity of soil = 250 kN/m2
To find length of footing
Taking moment about B,
4000 x 6.5 + 172 + 160 = 8000 X
X = 3.29m
Taking AB = 0.75m 7.2.1plan
Total length up to CG from A =3.29m+0.75m
=4.04m
Length of footing = 2(m+n)
= 2(0.75+3.29) = 8.08m
Length of projection CD = 0.83m
Taking 10% of total weight as self weight of foundation
Bearing area required = (8000+800) / 250
= 35.20 m2
Width of foundation = 35.20 / 8.08
= 4.36 m say 4.50m
Footing
Area = 8.08 x 4.50 = 36.36 m2
Net upward soil pressure = 8000 / 36.36
=
220.02kN/m2
Net upward soil pressure < safe
bearing capacity
220.02
kN/m2 < 250 kN/m2
Hence safe.
Bearing area per meter length =
220.02 x 4.50
= 990.09kN/m2
SF @ A =0
SF @ B left =742.57kN
SF @ B right =-3257.43kN
SF @ C left =3178.15
kN
SF @ C right =-821.85
kN
SF @ D = 0
To find shear
force at Zero 7.2.2.SFD &BMD
4000 – (0.75 x 990.09) – 990.09x = 0
X = 3.29m
To find Longitudinal bending
moment:-
Maximum hogging Bending moment,
M
max = 990.09 x 4.042 / 2 –
4000x3.29– 172
= -5252.08 kNm
Max sagging Bending moment:-
At Support, B
Mx = 990.09 x 0.75 2/ 2 -172
= 106.46kN.m
At support C,
Mu = 990.09 x 0.832 / 2
=
341.04kN.m
Thickness of footing based
on shear:-
The effective thickness of footing may be determined
by considering that the shear is resisted without shear reinforcement as
follows,
Vumax = ﺡc b.d
d = Vumax / ﺡc b
For one way Shear:-
Vumax
= Max ultimate shear at the section at distance‘d’
from the inner face of pedestal of column
C2.
=3178.15
– 990.09d
bo
= B = 4500mm
ﺡvu = shear strength of concrete in foundation slab
= Ks which may taken as
1.0, and shear strength of concrete which may be taken as its minimum value of
0.25 N/mm2
= 0.25
N/mm2
dx1000 = (3178.15 – 990.09d) x 1000 / (0.25 x
4500)
1125000d = 3178.15
x103 – 990.09x103 d
d = 1.50
m
= 1500mm. Say 1540mm
Over all depth = 1600mm
DESIGN FOR MOMENTS:-
The bottom reinforcement for
transverse moments is placed below the bottom reinforcement for longitudinal
moment. Distribution reinforcement in transverse direction.
= 0.12% of gross sectional area
= (0.12 / 100) x1000 x 1300
= 1560mm2 Provide 20mm # @ 200mmc/c
Use 20mm φ rods
Spacing = (314.15
/ 1560) x 1000
= 201.38mm say 200mm
1)
3d = 3 x 1240 = 3720mm
2)
And mm300
Which ever is minimum
Provide
20mm #@200mmc/c
Ast Calculation:-
Longitudinal span moment:-
Mu = 0.87 fy Ast d (1- (fyAst/fck
bd))
5252.08 x 106 = 0.87 x 415 x Ast x 1240 (1-
(415 x Ast / 25x4500x1240))
5252.08 x 106 = 447702 Ast – 1.33 Ast2
Ast =
12171.28mm2
Provide min Ast
= 0.12% of gross sectional area
= (0.12 / 100) x4500 x 1240 =6696mm2
Ast per meter length = (12171.28 / 4.5) = 2704.73mm2 /m
Use 25 mm φ rods
Spacing = (490.57
/ 2704.43) x 1000
= 181.49 mm Say 180 mm c/c
Provide 25mm # @ 180mmc/c
Support moment:-
Mu = 0.87
fy Ast d (1- (fyAst/fckbd))
341.04 x 106 =
447702 Ast – 1.33 Ast2
Ast = 763.49 mm2 < 6696 mm2
Ast per meter length = (6696 / 4.5) =1488mm2/m
Use 20 mm φ rods
Spacing = (314
/ 1488) x 1000
= 211.13 mm Say 200 mm c/c
Provide 20mm # @ 200mmc/c
7.3. DESIGN OF ISOLATED
FOOTING:-
DATA FOR DESIGN:
Axial load = 1541.4kN say 1800kN
Moment, Mx = 141.271
kN
Moment, Mz = -141.19kN
Safe bearing capacity of soil = 250kN/m2
Area required for foundation = 1800 / 250
Area required = LxB
BxB = 7.2m2
B2 = 7.2m2
B = 2.68m
L = 2.68m
Length required = 2.68 m 7.2.
Breadth required = 2.68 m 7.3.1.
Plan
Length provided = 2.70 m
Breadth provided = 2.70m
Original area = 2.70m
x 2.70m
= 7.29 m2
Column size:-
Length = 0.45m
Width = 0.45m
Self weight of the footing:-
Unit weight of concrete = 25.00kN/m3
Depth below Ground level = 2.40m
Depth of footing @ face of column = 1.00m
Depth of footing @ Edge of footing = 0.30m
Volume of footing:-
Volume of frusta of pyramids and concrete,
=
(1.00 – 0.30) / 3 ((0.45 x 0.45) + (2.70x 2.70) +
(0.45 x 0.45 x 2.70 x 2.70)
=1.559m3
Thickness of footing required against bending moments:-
Mumax = Qubd2
431.52 x 106= 0.138
x25x 2700x d2
d = 215.23mm
Say 220mm
D = 220+
60
= 280mm
Upward soil pressure at B = 203.86
+ (203.06 – 289.98) / 2.7
X (2.7 -1.125-0.45)
= 240.102kN/m2
Mux
= Muy = Pnu Lx ((B-b)
2/ 8)
= 240.102 x 2.7 x (2.7-0.45)2 /
8
= 410.24kNm
Maximum Bending moment @ face of column = 410.24kNm
Mumax = Qubd2
410.24 x 106= 0.138x25x2700
xd2
d =
(410.24 x 106)
/ 0.138x25x2700
= 209.85 mm say220mm
D = 220 + 60
= 280mm 7.3.2 one way shear plan
Check for Effective depth
required against shear:-
The critical section of shear is taken at a distance of‘d’ from the
pedestal
Vu max =Pu B ((L-a)/2) –d)
=252.56
x 2.70 x (2.70- 0.45) /2 –d)
=681.912(1.125
–d)
Vumax =767.15 – 681.91 d
The total shear stress induced at critical section is
resisted by the shear stress, developed by concrete section,
Ks = 0.5
+ βc
= 1.50
>1
Ks = 1
حc = 0.25
fck
= 1.25N/mm2
7.3.2 critical section plan
حcu = 1x1.25
=
1.25N/mm2
حvu = (Vumax/bd)
حvu = (767.15 – 681.91d)/2700
x d
حvu = حcu
1.25x103 = (767.15 – 681.91d)/2.70d
d = 0.189m
d = 189 mm
D = 250mm
Vumax = Pnu ((LxB – (a+d) (b+d))
=
252.56(2.70x2.70 –
(0.45+d)(0.45+d))
= 252.56(7.088-d2-0.9d) 7.3.3
Two way shear plan = 1719.27 – 218.30d – 252.56 d2
ﺡvu = (Vumax)/(2(a+d)+2(b+d))d)
= 1719.27
– 218.30d – 252.56 d2 /
(2(0.45+d)
+2(0.45+d)) x d
1.25 x 103 (1.8d + 4d2) = 1719.27 – 218.30d –
252.56 d2
5252.56 d2 + 2468.30 d – 1719.21 = 0
d = 384mm say 390mm
D = 450mm Provide maximum depth d = 450mm
Reinforcement along x
direction:-
Mu = 0.87
fy Astd(1- (fyAst/fck bd))
431.52 x 106 =
0.87 x 415 x Ast x 390(1-
(415 x
Ast
/ 25x2700x390))
Ast = 3228.94mm2
Provide 20mm dia bars.
No of bar = 3228.94 / ((π /4) x 202)
= 10.28 nos Say 11nos
CONCLUSION
Our project deals with planning,
analysis and design of shopping complex
using STAAD Pro at Vadapalani, Chennai.
The shopping complex is
designed with all necessary facilities such as shops, super markets, coffee
shops, Food courts, offices, Escalators, Lifts etc., as per BIS specifications.
In this project, the
Analysis of frame is done by stiffness matrix method using STAAD Pro. Software.
Design of footings, columns, beams & slabs
are done manually by limit state method as per IS456 – 2000, IS 1893-2002 and SP16.
All sites are working.. This is great thing..A huge thanks from my side…:)
ReplyDeleteBoom Lift Rental In Pune