The building is located in seismic zone V and the basic wind speed in this location is 55m/s. The preliminary gravity and lateral load analysis are carried out manually for a typical 2D frame and compared with software results. The member sizes for beams and columns were found out from the preliminary manual analysis and design. 3D finite element modeling was carried out in ETABS for the building. Based on the analytical results (moment, shear force), the member sizes are finalized and design was carried out as per the codes IS 456, SP16, IS 13920. Ductile design and detailing is carried out as per IS 13920 & SP34.
2. PROJECT DESCRIPTION
The Hospital building is a G+8 structure and
its height is 32.08m from above the ground
level. It is located in zone V.
The structure is modeled in ETABS software.
Based on the analytical results (moment, shear
force), the member sizes are finalized and
designed.
Ductile design and detailing is carried.
3. BUILDING FUNCTION
Ground
Floor
1st
floor
2nd
Floor
3rd
floor
4th – 8th
floor
Store room
Kitchen
Pantry
Dining hall
(120 persons)
multipurpose
hall
Lecturer hall-1
(100 persons)
Waiting area
Lobby
Toilet
Laboratories
Lecturer hall-2
Principal
Room
Faculty room
Office room
Waiting area
Toilet
Laboratories
Lecturer hall-3
Faculty room
Common
room
Stores
Waiting area
Toilet
Recreation
room
Library
Study hall
Computer Lab
Lecturer hall-3
counseling
room
Waiting area
Toilet
Hostel
rooms
Toilet
4. CODAL PROVISION
LOAD TYPE CODES USED
Gravity load IS 875 part 1&2
Wind load IS 875 Part 3
Seismic load IS 1893
Load combination IS 875 part 5
5. GENERAL DATA
Plinth area 963.9m2
Building type Framed structure
Building designation Training Institute & Hostel block
Types of soil Hard – Type III
Basic wind speed 55 m/s
Seismic zone V
Safe bearing capacity of soil 450 kN/mm2
Type of foundation Isolated footing
Type of slab Conventional 1 way slab
Type of staircase Dog-legged
Number of stories G+8
6.
7. AREA LOADING SUMMARY - as per IS 875 part 1
S.NO DESCRIPTION FLOOR
FINISH
kN/m2
SCREEDING
kN/m2
FALSE
CEILING
kN/m2
FILLING
kN/m2
TOTAL
DL
kN/m2
IMPOSED
LOAD
kN/m2
1 Lobby 1 0.2 1.2 3
2 Corridors 1 0.2 1.2 4
3 Dining hall 1 0.2 1.2 3
4 Kitchen 1 0.2 1.2 3
5 Toilet Area 1 0.2 1.2 2
6 Drying and
washing
1 0.2 1.2 2
7 Store area 1 0.2 1.2 5
8 Multipurpose
hall
1 0.2 0.5 1.2 3
9 Lecture hall 1 0.2 1.2 4
10 Electrical room 1 0.2 1.2 3
11 Lab 1 0.2 0.5 1.2 3
9. I FLOOR DEAD IMPOSED LOAD &
LIVE LOAD
AREA LOADING DIAGRAM
II FLOOR DEAD IMPOSED LOAD &
LIVE LOAD
10. AREA LOADING DIAGRAM
III FLOOR DEAD IMPOSED LOAD &
LIVE LOAD
IV, V, VI,VII & VIII FLOOR DEAD IMPOSED LOAD &
LIVE LOAD
11. BRICKWALL LOADING
Brick wall loading = Thickness of wall x Unit wt of wall x ht of the wall
FLOORS FOR 125mm WALL
kN/m
FOR 250mm WALL
kN/m
Ground Floor 15.75 7.875
First Floor 15.75 7.875
Second Floor 15.75 7.875
Third Floor 17.25 8.625
Fourth Floor 12.75 6.375
Fifth Floor 12.75 6.375
Sixth Floor 12.75 6.375
Seventh Floor 12.75 6.375
Eighth Floor 12.50 6.250
Terrace 03.00
Staircase head room 10.75
12. WIND LOAD CALCULATION
Data Values As per IS 875 Part 3 1987
Basic wind speed 55 Appendix A
Risk coefficient, k1 1.00 Table1
Terrain factor, k2 varies with height Table 2
Terrain category, k3 3 Cl 5.3.2.3
Class C Cl 5.3.2.2
Width of building, a 63m Along X
Length of building, b 15.35m Along Y
No of stories 8 Including Terrace
Height of the building 36.9m
Wind force, F Cf Ae Pz Referring fig 4
Force Coefficient Cfx =1
Cfy =1.18
For wind along X,
For wind along Y.
14. MANUAL ANALYSIS OF FRAME
CONSIDER A FRAME 7-7,
Gravity load acting on each beam and Lateral load acting on each floor
The considered frame is analyzed manually by moment distribution method for gravity
and lateral loads.
The software comparison is done and has been concluded that theoretical values match
with the Software values.
Preliminary design of beam and column is carried out.
A typical beam and column is considered, say Beam AB and Column AD of ground floor
is considered.
The moment acting on the column and beam is taken.
Using IS 456: 2000 code Beam is designed and using SP 16 code column is designed.
15. ETABS MODELLING INPUTS AND OUTPUTS:
Material properties
Grade of concrete:
Column, Beam, Tank wall & Slab M30
Grade of steel: Fe 500
Structural element
S.No ELEMENTS DESCRIPTION IN ETABS
1 COLUMN C 900X750, C 750X900
C 900X450, C 450X900
2 BEAM B 250X600, B 300X600, B 450X600,
B 450X450, B 300X450, WT 200X1500
3 SLAB MEM 125, MEM 150, MEM 325
16. LOAD CASES
Gravity load case:
DL Self weight
DI Super imposed load
LL 1 live load greater that 3
LL 2 live load lesser than 3
Seismic load case:
Response spectrum user defined file
ELX Res spec x
ELY Res spec y
Wind load case:
Applied as point load in floor diaphragms
WLX Wind load along X direction
WLY Wind load along Y direction
17. CALCULATION OF RESPONSE SPECTRUM COEFFICIENT:
As per IS 1893 part 2,
Zone factor, Z 0.36
Importance factor, I 1
Response factor, R 5
Type of soil Hard
For Hard Soil Sites
Sa/g 1+15T 0<=T<=0.1
2.5 0.1<=T<=0.4
1/T 0.4<=T<=4
LOAD COMBINATION:
Seismic load case have both maximum and minimum load cases for +ve and –ve
directions respectively , Ref IS 1893: 2002, Table 1 , Pg 15.
Column design live load is considered as per IS 875- part 2, 1987.
Design load combination:
Basic load combinations
Seismic load combinations
Wind load combinations
18. OUTPUTS:
1.) General data:
Height of the building 32.5m
Width in X- direction 63m
Width in Y- direction 19m
Seismic weight of the
building, W
152220 kN
Zone factor, Z 0.36
Importance factor, I 1
Response factor, R 5
2.) Fundamental natural period
Y-Direction(without infill)
T 1.02sec
X–Direction(with infill)
T 0.368sec
3.)Calculation of Sa/g for Hard soil,
Y- Direction, 0.98
X- Direction, 2.5
4.) Calculation of Ah:
Y-Direction(without infill)
Ah= (ZI/2R) X Sa/G 0.035
X–Direction(with infill)
Ah=(ZI/2R) X Sa/G 0.09
5.) Base shear Vb= AhXW
X-Direction
Vb’ = 0.09 x 149769 13480kN
Y–Direction
Vb’ =0.035 x 149769 5242kN
6.) Base shear (from analysis)
X-Direction
Vb 2952kN
Y–Direction
Vb 2865kN
7.) Multiplication factor
X-Direction(Vb’/Vb) 4.56
Y–Direction(Vb’/Vb) 1.83
19. CHECK BASE REACTION FOR SCALE FACTOR
BASE REACTION FOR SCALE FACTOR =1
BASE REACTION FOR SCALE FACTOR =4.56
LOAD CASE Fx Fy Fz
ELX max 2952 - -
ELY max - 2865 -
SEISMIC
WEIGHT
- - 149769
LOAD CASE Fx Fy Fz
ELX max 13819 - -
ELY max - 13408 -
SEISMIC
WEIGHT
- - 149769
22. BENDING MOMENT DUE TO GRAVITY LOAD AND
LATERAL LOAD ACTING ON SECTION 6-6
23. DESIGN OF BUILDING
The design method adopted is Limit state method. The building is designed as per IS 456:
2000 and SP 16.
SLAB DESIGN
First floor slab is designed as per IS 456:2000 and detailing is drawn as per Sp 34.
BEAM DESIGN
A full span of beam for first floor is designed as per IS 456:2000 and detailing is
drawn as per Sp 34.
STAIRCASE DESIGN
Dog-leg type staircase is adapted. It is designed as per IS 456:2000 and detailing is
drawn as per Sp 34.
COLUMN DESIGN
Column for first floor is designed as per IS 456:2000 and Sp16. And detailing is
drawn as per Sp 34.
FOOTING DESIGN
Isolated footing type is adapted. It is designed as per IS 456:2000 and Sp16. And
detailing is drawn as per Sp 34.
DUCTILE DESIGN
Ductile design is carried out as per IS: 13920-1993 and Sp16. And detailing is drawn
as per Sp34
24. Structural
components
AMOUNT OF REINFORCEMENT USED
SLAB
DESIGN
Depth = 130mm
Main reinforcement:
Provide 10mm dia bars @ 270mm c/c and alternate bars are bent up at
supports.
Distribution reinforcement:
Provide 8mm dia bars @ 300mm c/c.
BEAM
DESIGN
(450x600mm)
amount of reinforcement in the
top layer:
First layer, 4 – Y32
Second layer, 4 – Y25
Third layer, 4 – Y20
Amount of reinforcement in the
bottom layer:
First layer, 4 – Y25
Second layer, 4 – Y16
STAIRCASE
DESIGN 175mm
Main reinforcement - 416mm2
Distribution reinforcement - 216 per m
COLUMN
DESIGN
700x900mm
Use 32mm dia bars of 4 nos and 25mm dia bars of 28 nos distributed in
four sides.
FOOTING
DESIGN
Reinforcement in central band width – 17400mm2
Minimum reinforcement – 1440mm2
DUCTILE
DESIGN
Anchorage of external bars:
Top reinforcement = 4Y + 10Y – 8Y = 1568mm
Bottom reinforcement = 4Y + 10Y – 8Y = 1225mm