Friday 28 October 2016

                              LITERATURE REVIEW

Earthquake is a phenomenon that devastates the entire humankind. During such an event the

casualties are found to be in a large number because of the poorly constructed structures in

which we reside in. The major cause were found to be the weak beam-column joints, soft

ground storeys, improper and inadequate detailing, complex plan configuration and many more

by Prof C.V.R MURTY’S many research papers and publishes. IIT K people have done a decent

job in the preparation of examples on Earthquake resistant design of buildings. And also EERC

HYD people have found some critical reasons behind the collapse of buildings. The stiffness

variation and improper detailing are the reasons in common among all. Indian codes as well as

Euro codes laid recommendations for the design. The problems: stiffness variation and

improper detailing had been taken into consideration in the task. It is always the smart

buildings which perform better than the sturdiest one during an earthquake.


CHAPTER-1 DESIGN
According to IS: 456-2000, there are three methods for design of RC, Pre-stressed and Steel Structures which are as followed:
a)      Working Stress Method
b)      Ultimate Load method
c)      Limit State Method(this method is followed in this report)

1.1 Limit State Method
In this method, all relevant limit states are considered in design to ensure an adequate degree of safety and serviceability. According to this method, the structure can achieve two different types of limit states:
a)      Limit State of collapse
b)      Limit state of serviceability

1.1.1 Limit State of Collapse
This limit may corresponds to Maximum load carrying capacity. Four different types of behavior of structure are:
a)      Flexure
b)      Compression
c)      Shear
d)      Torsion

1.1.2 Limit State of Serviceability
This limit state corresponds to development of excessive deformation. Three different types of behavior of structure in this state are:
a)      Deflection
b)      Cracking
c)      Vibration


 

1.2 General Principles of Earthquake Resistant Buildings

The most happening principles to be considered for the design of earthquake –resistant structures are discussed as followed:
a)      Design Basis Earthquake
b)      Pseudo-Static Earthquake
c)      Components of Acceleration
d)      Increase in Permissible Stresses
e)      Increase in Allowable Bearing Capacity
f)       Horizontal and Vertical Inertia  Forces
g)      Resonance
h)      Base Shear

CHAPTER-2 BUILDING PLANNING

2.1 Plan for G+2 Residential Building
The following two storey building is an RCC building with 18.35m length and 11.29m width. Floor to floor height from ground floor is 2m and for the other remaining stories, height is 3m (Total height 11m).
2.1.1 Orientation
After having selected the site, the next step is proper orientation of building. Orientation means proper placement of rooms in relation to sun, wind, rain, topography and outlook and at the same time providing a convenient access both to the street and back yard. 
The factors that affect orientation most are as follows. 
ü  Solar heat 
ü  Wind direction 
ü  Humidity 
ü  Rain fall 
ü  Intensity of wind site condition 
ü  Lightings and ventilation

Based on it, arrangement of rooms are given as followed:
Table 2.1 Aspects of Room
S. No
Room
Aspect
1
Bed
NW – W - SE
2
Kitchen
E & rarely NE
3
Dinning
SE – S – SW
4
Drawing
SE – S – SW - W
5
Reading
N – NW
6
Store
NW – N – NE
Based on these factors, the plan layout is as shown below:        

     Building Plan

The building plan involves series of steps to achieve a proper detailed design of the building. The steps involved in this process are:
2.2 Grid Line Marking
The orientation of the columns is done in such a way to utilize the complete capacity of them. In general the depth of the column is placed along the longer direction to provide proper stability to structure.
2.3 Slab Numbering
2.4 Structural Details
Based on the Thumb-Rules which are in IS 456-2000, the details of Building are given as below in table 2.2.           

Table 2.2 Structural Details
Total Length in X direction
11.29m
Total length in Y direction
18.35m
Total Height
8m
Live Load(Typical floor)
3 KN/m2
Live load ( Terrace)
1.5 KN/m2
Floor Finish(Typical Floor)
1 KN/m2
Water Proofing(Terrace)
1.2 KN/m2
Location
Guwahati
Zone no.
V
Z : Zone Factor
0.36
I : Importance Factor
1
R : Response Reduction Factor (OMRF)
3
Column Dimension
0.3x0.4m
Beam Dimension
0.23x0.3m
Slab Thickness
0.12m
External wall Thickness
0.23m
Internal, Parapet, Gallery wall Thickness
0.12m
Concrete Grade
M20
Steel Grade
Fe415

2.5 Gravity Load Calculations
The gravity loads are considered as per IS: 875. The different loads are considered as followed:
Table 2.3 Assumed Loads on Structures (IS 875 (Part I & II))
Live Load (Typical Floor)
3     KN/m2
Live Load (Terrace)
1.5  KN/m2
Floor Finish (Typical Floor)
1     KN/m2
Water Proofing (Terrace)
1.2  KN/m2






Table 2.4: Gravity Loads on Slab
Type of load
Name of load
Typical floor
Terrace
Units
Dead load
Self-Weight
3
3
KN/m2

Floor Finish
1
1
KN/m2

Water Proofing
-
1.2
KN/m2

Total
4
5.2
KN/m2
Live load

3
1.5
KN/m2

2.6 Transfer of Loads from Slabs to Beams
The gravity loads are transferred from slabs to beams, beams to columns, columns to foundations and foundations to soil. The loads coming from slabs to beams are transferred based on yield line theory. There are two types of slabs:

                                              

                                                                      Table 2.5 Load Distribution of Slab
SLAB  DESIGN
Slab Name
Llonger
Lshorter
Ll/Ls
Type
S1
5
4
1.25
Two Way
S2
4
3
1.33
Two Way
S3
5
4
1.25
Two Way
S4
5
3
1.67
Two Way
S5
3
3
1.00
Two Way
S6
5
3
1.67
Two Way
S7
6
5
1.20
Two Way
S8
6
3
2.00
Two Way
S9
6
5
1.20
Two Way
S10
5
3
1.67
Two Way
S11
3
3
1.00
Two Way
S12
5
3
1.67
Two Way
S13
5
4
1.25
Two Way
S14
4
3
1.33
Two Way
S15
5
4
1.25
Two Way
S16
3
2
1.50
Two Way
S17
5
2
2.50
One Way


Slab Name
Llonger
Lshorter
    Dead Load(kN/m)
Live Load(kN/m)
Typical Floor 
Terrace
Typical Floor 
Terrace
(m)
(m)
Lshorter
Llonger
Lshorter
Llonger
Lshorter
Llonger
Lshorter
Llonger
S1
5
4
5.33
12.91
6.93
16.78
4
9.68
2
4.84
S2
4
3
4.00
10.13
5.20
13.16
3
7.59
1.5
3.80
S3
5
4
5.33
12.91
6.93
16.78
4
9.68
2
4.84
S4
5
3
4.00
11.52
5.20
14.98
3
8.64
1.5
4.32
S5
3
3
4.00
4.00
5.20
5.20
3
3.00
1.5
1.5
S6
5
3
4.00
11.52
5.20
14.98
3
8.64
1.5
4.32
S7
6
5
6.67
15.65
8.67
20.34
5
11.74
2.5
5.87
S8
6
3
4.00
12.50
5.20
16.25
3
9.38
1.5
4.69
S9
6
5
6.67
15.65
8.67
20.34
5
11.74
2.5
5.87
S10
5
3
4.00
11.52
5.20
14.98
3
8.64
1.5
4.32
S11
3
3
4.00
4.00
5.20
5.20
3
3.00
1.5
1.50
S12
5
3
4.00
11.52
5.20
14.98
3
8.64
1.5
4.32
S13
5
4
5.33
12.91
6.93
16.78
4
9.68
2
4.84
S14
4
3
4.00
10.13
5.20
13.16
3
7.59
1.5
3.80
S15
5
4
5.33
12.91
6.93
16.78
4
9.68
2
4.84
S16
3
2
2.67
7.26
3.47
9.44
2
5.44
1
2.72
S17
5
2

4.00

5.20

3.00

1.50



2.7 Wall Load Calculations
External Wall(230 mm thick )
12KN/m
Internal Wall(120mm thick)
6.25KN/m
Gallery Wall(120mm thick)
3KN/m
Parapet Wall(230mm thick)
4KN/m
Self-Weight of Beam (Load/unit weight)
1.725KN/m

 table 2.6 Wall Load Calculations





2.8 Load Distribution by Yield Line Theory on Typical Floor

Load Distribution by Yield Line Theory on Top Floor
Total Loading on All Frames 

frame 1-1

frame 2-2

frame 3-3
frame 4-4

frame 5-5
frame 6-6
frame 7-7
2.9 Analysis of 2D Frame Using Kani’s Method (For Frame A-A)
Out of all the classical methods of analysis of portal frame, this method is the easiest and approximate method. Though it is an iterative process, it is self-correcting. This method uses the following formulas:
Fixed End Moments:                 


        








Final End Moments:



             
              



CHAPTER-3 3D model SAP 2000                                                                                                                                                                           
3.1 3D View of Building Plan
CHAPTER-4 LATERAL LOAD ANALYSIS

The primary purpose of all kinds of buildings is to resist gravity loads besides vertical loads caused by wind loads, blasting or earthquake also develop high stresses, produce sway movements or causes vibration. Therefore, it is important for a structure to resist against vertical loads together with gravity loads.

4.1 Methods for Determining of Design Lateral Loads
    a)  Equivalent Static Method
    b)  Dynamic Analysis
              1) Response Spectrum Analysis
              2) Time History Analysis

4.1.1 Equivalent Static Method
This Concept is most commonly used because it converts dynamic forces into equivalent static forces for finding out the maximum displacements induced in the structure. This equivalence is restricted to a single mode of vibration of the structure.
Step 1:
Preliminary data from IS 1893:
  • Building Height is less than 90m hence; Equivalent Static Analysis (ESA) can be applied.
  • Building is located in Guwahati in Zone V, so Zone Factor Z = 0.36(IS 1893).
  • Building is resting on soft soil.

Step 2:




Table 4.1 Seismic Weight of Ground Floor
Components
Length (m)
Width (m)
Depth (m)
Density (kN/m3)
Numbers
Weight (kN)
Beam along Y
23.5
0.3
0.4
25
4
282
Beam along X
13.9
0.3
0.4
25
7
291.90
Column
2.5
0.3
0.4
25
28
210
External wall Load along X
27.8
0.23
1.35
20
1
172.64
External wall Load along Y
21.5
0.23
1.35
20
2
267.03
Internal wall Load along X
33.8
0.11
1.35
20
1
100.3 9
Internal wall Load along Y
37.1
0.11
1.35
20
1
110.19
Gallery wall load
10.6
0.11
1.25
20
1
29.15
Stair case Load 
12.06
12.06
Stair case Live Load 
10
10
25% OF live load
2.5
2.5
Total Seismic Load(25% Live Load)
1477.85

Table 4.2 Seismic Weight of Typical Floor
Components
Length (m)
Width (m)
Depth (m)
Density (kN/m3)
Numbers
Weight (kN)
Slab 1 Load
8.6
2
0.18
25
1
77.4
Slab 2 Load
13.9
21.3
0.18
25
1
1332.32
Beam along Y
23.5
0.3
0.4
25
4
282
Beam along X
13.9
0.3
0.4
25
7
291.90
Column
2.5
0.3
0.4
25
28
210
Floor Slab 1
8.6
2
0
1
1
17.2
Floor Slab 2
13.9
21.3
0
1
1
296.07
External wall Load along X
27.8
0.23
2.7
20
1
345.28
External wall Load along Y
21.5
0.23
2.7
20
2
534.06
Internal wall Load along X
33.8
0.11
2.7
20
1
200.77
Internal wall Load along Y
37.1
0.11
2.7
20
1
220.37
Gallery wall Load
10.6
0.11
1.25
20
1
29.15
Stair case Load 
15

3851.52
Live load Slab 1
8.6
2
0
3
1
51.6
Live load Slab 2
13.9
21.3
0
3
1
888.21
Stair case Live Load 
5.7
25%live load
236.38

Total Seismic Load (25% Live Load)
4087.89

Table 4.3 Seismic Weight of Top Floor
Components
Length (m)
Width (m)
Depth (m)
Density (kN/m3)
Numbers
Weight (kN)
Slab 1 Load
8.6
2
0.18
25
1
77.4
Slab 2 Load
13.9
23.5
0.18
25
1
1469.93
Beam along Y
23.5
0.3
0.4
25
4
282
Beam along X
23.9
0.3
0.4
25
7
501.90
Column
1.5
0.3
0.4
25
28
126
External wall Load along X
27.8
0.23
1.35
20
1
172.64
External wall Load along Y
21.5
0.23
1.35
20
2
267.03
Internal wall Load along X
33.8
0.11
1.35
20
1
100.39
Internal wall Load along Y
37.1
0.11
1.35
20
1
110.19
Stair case Load 
2
30

Total Seismic Load
3137.47

Step 3:
Fundamental Natural Period
Of a moment resisting frame building without brick infill panels may be estimated as           

    
4.1.2     Distribution of Base Shear To Storey Shear
Step 7:
Table 4.4 Distribution of Base Shear to Storey Shear

STOREY
Wi (kN)
H (m)
Wi*Hi2
Qi (kN)
3
3137.47
8
200798
849
2
4087.89
5
102197
432
1
1477.85
2
5911
25
SUMMATION
308907
1305
Seismic Force at Floor Levels along X-direction (all units in KN)

4.1.3 Distribution of Lateral Storey Load to each Frame
Distribution of Lateral Load to each frame is in proportion to stiffness of each frame.
             Table 4.5 Distribution of Storey Shear to Frame Shear along X-direction

Frame
Stiffness (kN/m)
Dis.Factor
I-Storey
II-Storey
III-Storey



Grid 1
10000
0.14
3.50
60.47
118.80
Grid 2
10000
0.14
3.50
60.47
118.80
Grid 3
10000
0.14
3.50
60.47
118.80
Grid 4
10000
0.14
3.50
60.47
118.80
Grid 5
10000
0.14
3.50
60.47
118.80
Grid 6
10000
0.14
3.50
60.47
118.80
Grid 7
10000
0.14
3.50
60.47
118.80

Table 4.6 Distribution of Storey Shear to Frame Shear along Y-direction
Frame
Stiffness (kN/m)
Dis.Factor
I-Storey
II-Storey
III-Storey



Grid A
25000
0.25
6.25
107.98
212.1
Grid B
25000
0.25
6.25
107.98
212.1
Grid C
25000
0.25
6.25
107.98
212.1
Grid D
25000
0.25
6.25
107.98
212.1

 4.2 Centre of Mass and Centre of Stiffness Calculations
 4.2.1 Centre of Mass         
     
                   
                                 
             Where Wi =Weight of components (Slab, Beam, Wall, Column and Staircase)


                                                                                                                                                                                   
Component
CG(X) (m)
CG(Y) (m)
Breadth (m)
Length (m)
Mass (Kg)
M x X
M x Y
Slab 1 
9.56
22.3
2
8.53
7677
73392.12
171197.1
Slab 2
6.91
10.65
21.3
13.83
132560.55
915993.4
1411769.86
Beam 1
6.91
0
0.3
13.83
4149.00
28669.59
0
Beam 2
6.91
4.3
0.3
13.83
4149.00
28669.59
17840.70
Beam 3
6.91
7.53
0.3
13.83
4149.00
28669.59
31241.97
Beam 4
6.91
13.76
0.3
13.83
4149.00
28669.59
57090.24
Beam 5
6.91
17.0
0.3
13.83
4149.00
28669.59
70491.51
Beam 6
6.91
21.29
0.3
13.83
4149.00
28669.59
88332.21
Beam 7
6.91
23.3
0.3
13.83
4149.00
28669.59
96671.70
Beam 8
0
11.65
0.3
23.3
6990.00
0
81433.50
Beam 9
5.3
11.65
0.3
23.3
6990.00
37047.00
81433.50
Beam 10
8.53
11.65
0.3
23.3
6990.00
59624.70
81433.50
Beam 11
13.83
11.65
0.3
23.3
6990.00
96671.70
81433.50
Wall 1
9.56
23.3
0.11
8.53
2345.75
22425.37
54655.98
Wall 2
13.83
22.3
0.11
2
550
7606.5
12265
Wall 3
6.91
21.3
0.23
13.83
19085.4
131880.11
406519.02
Wall 4
2.65
17.0
0.11
5.3
3498
9269.7
59431.02
Wall 5
11.18
17.0
0.11
5.3
3498
39107.64
59431.02
Wall 6
2.65
13.76
0.11
5.3
3498
9269.7
48132.48
Wall 7
2.65
7.53
0.11
5.3
3498
9269.7
26339.94
Wall 8
11.18
7.53
0.11
5.3
3498
39107.64
26339.94
Wall 9
2.65
4.3
0.11
5.3
3498
9269.7
15041.4
Wall 10
6.91
0
0.23
13.18
18188.4
125681.84
0
Wall 11
1
11.76
0.11
2
1320
1320
15523.2
Wall 12
0
21.3
0.23
21.3
29394
0
626092.2
Wall 13
2
14.26
0.11
5
3300
6600
47058
Wall 14
5.3
19.14
0.11
4.3
2838
15041.4
54319.32
Wall 15
5.3
10.64
0.11
6.23
4111.8
21792.54
43749.55
Wall 16
5.3
2.15
0.11
4.3
2838
15041.4
6101.7
Wall 17
8.53
12.26
0.11
9.43
6223.8
53089.01
76303.79
Wall 18
8.53
3.76
0.11
7.53
4969.8
42392.4
18686.45
Wall 19
13.83
10.65
0.23
21.3
29394
406519.02
313046.1
Stair case
5.3
22.3
2
0.16
96
508.8
2140.8
342884
2348908.5
4181546.2
                                               Table 4.7 Centre of Mass Calculation

Centre of Mass
                                                            
Table 4.8 Centre of Stiffness Calculation

Component
CG(X) (m)
CG(Y) (m)
Width (m)
Depth (m)
Leangth (m)
Kx
Ky
Kx * X
Ky * Y
Column 1
0
0
0.3
0.4
3
15.90
8.94
0
0
Column 2
5.3
0
0.3
0.4
3
15.90
8.94
84.27
0
Column 3
8.6
0
0.3
0.4
3
15.90
8.94
136.75
0
Column 4
13.9
0
0.3
0.4
3
15.90
8.94
221.02
0
Column 5
0
4.3
0.3
0.4
3
15.90
8.94
0
38.46
Column 6
5.3
4.3
0.3
0.4
3
15.90
8.94
84.27
38.46
Column 7
8.6
4.3
0.3
0.4
3
15.90
8.94
136.75
38.46
Column 8
13.9
4.3
0.3
0.4
3
15.90
8.94
221.02
38.46
Column 9
0
7.6
0.3
0.4
3
15.90
8.94
0.00
68.0
Column 10
5.3
7.6
0.3
0.4
3
15.90
8.94
84.27
67.98
Column 11
8.6
7.6
0.3
0.4
3
15.90
8.94
136.75
67.98
Column 12
13.9
7.6
0.3
0.4
3
15.90
8.94
221.02
67.98
Column 13
0
13.9
0.3
0.4
3
15.90
8.94
0.00
124.33
Column 14
5.3
13.9
0.3
0.4
3
15.90
8.94
84.27
124.33
Column 15
8.6
13.9
0.3
0.4
3
15.90
8.94
136.75
124.33
Column 16
13.9
13.9
0.3
0.4
3
15.90
8.94
221.02
124.3
Column 17
0
17.2
0.3
0.4
3
15.90
8.94
0.00
153.84
Column 18
5.3
17.2
0.3
0.4
3
15.90
8.94
84.27
153.84
Column 19
8.6
17.2
0.3
0.4
3
15.90
8.94
136.75
153.84
Column 20
13.9
17.2
0.3
0.4
3
15.90
8.94
221.02
153.84
column 21
0
21.5
0.3
0.4
3
15.90
8.94
0.00
192.30
column 22
5.3
21.5
0.3
0.4
3
15.90
8.94
84.27
192.30
column 23
8.6
21.5
0.3
0.4
3
15.90
8.94
136.75
192.3
column 24
13.9
21.5
0.3
0.4
3
15.90
8.94
221.02
192.30
column 25
0
23.5
0.3
0.4
3
15.90
8.94
0.00
210.19
column 26
5.3
23.5
0.3
0.4
3
15.90
8.94
84.27
210.19
column 27
8.6
23.5
0.3
0.4
3
15.90
8.94
136.75
210.19
column 28
13.9
23.5
0.3
0.4
3
15.90
8.94
221.02
210.19


Table 4.9 Final Lateral Force in Frames along X direction
Frame
Storey 1
Storey 2
Storey 3
1
3.94
68.16
133.91
2
3.80
65.66
128.99
3
3.69
63.70
125.15
4
3.54
61.08
120.00
5
3.65
63.09
123.96
6
3.80
65.66
128.99
7
3.87
66.88
131.39
A
0.63
10.83
21.28
B
0.15
2.59
5.10
C
0.12
2.14
4.20
D
0.58
10.07
19.78

Table 4.10 Final Lateral Force in Frames along Y direction

Frame
Storey 1
Storey 2
Storey 3
1
0.44
7.69
15.11
2
0.30
5.19
10.19
3
0.19
3.23
6.35
4
0.04
0.61
1.20
5
0.15
2.62
5.16
6
0.30
5.19
10.19
7
0.37
6.41
12.59
A
6.88
118.81
233.38
B
6.40
110.57
217.20
C
6.37
110.12
216.30
D
6.83
118.05
231.88
                                           
. 4.4: Storey Drift
 Storey drift in any storey due lateral force shall not exceed 0.004 times the storey height
Table 4.11 Storey Drift Calculations in X- direction 
STOREY
HEIGHT(mm)
DISP.(mm)
STOREY DRIFT
MAX. DRIFT
LIMIT
II FLOOR
3000
18.8
6.9
12
OK
I FLOOR
3000
11.9
9.1
12
OK
PLINTH
2000
2.8
2.8
8
OK
  
Table 4.12 Storey Drift Calculations in Y- direction
STOREY
HEIGHT(mm)
DISP.(mm)
STOREY DRIFT
MAX. DRIFT
LIMIT
II FLOOR
3000
17
6
12
OK
I FLOOR
3000
11
8.4
12
OK
PLINTH
2000
2.6
2.6
8
OK
  
Hence the building is safe.
  
CHAPTER-5 DESIGN OF SLAB
Example Solution for Slab1: 
                      Table 5.1 Assumed Data of Depth
ASSUMED DEPTH
Depth
120mm
Diameter of Bar
10mm
Cover
15mm
Support Width
300mm
Effective Depth Along X
100mm
Effective Depth Along Y
90mm
     





Effective Depth:
spacing required= 185.83mm
5.1.1 Loading on Slab
Table 5.3 Loading on Slab (all units are kn/m2)
Self-Weight of slab
Floor finish
1
Live load(For typical floor)
3
Live load (For terrace)
1.5
Factored Dead load
Factored live load

Table 5.4 Effective Length and Bending Moment Coefficients

Slab Name
Llonger
Lshorter
Depth of Slab (D) (mm)
ɸ of Bar (mm)
Cover(C) (mm)
Support Width (mm)
Ll/Ls
Type
S1
5
4
120
10
15
230
1.25
Two Way
S2
4
3
120
10
15
230
1.33
Two Way
S3
5
4
120
10
15
230
1.25
Two Way
S4
5
3
120
10
15
230
1.67
Two Way
S5
3
3
120
10
15
230
1.00
Two Way
S6
5
3
120
10
15
230
1.67
Two Way
S7
6
5
120
10
15
230
1.20
Two Way
S8
6
3
120
10
15
230
2.00
Two Way
S9
6
5
120
10
15
230
1.20
Two Way
S10
5
3
120
10
15
230
1.67
Two Way
S11
3
3
120
10
15
230
1.00
Two Way
S12
5
3
120
10
15
230
1.67
Two Way
S13
5
4
120
10
15
230
1.25
Two Way
S14
4
3
120
10
15
230
1.33
Two Way
S15
5
4
120
10
15
230
1.25
Two Way
S16
3
2
120
10
15
230
1.50
Two Way
S17
5
2
120
10
15
230
2.50
One Way






Design Moments
                                        Table 5.5 Design Moments according to IS 456


αx-
αx+
αy-
αy+
0.0854
0.064
0.047
0.035
0.078
0.06
0.037
0.028
0.085
0.064
0.047
0.035
0.057
0.044
0.037
0.028
0.051
0.039
0.032
0.024
0.057
0.044
0.037
0.028
0.044
0.033
0.037
0.028
0.043
0.032
0.047
0.035
0.044
0.033
0.037
0.028
0.044
0.033
0.037
0.028
0.043
0.032
0.032
0.024
0.044
0.033
0.037
0.028
0.067
0.051
0.037
0.028
0.07
0.058
0.047
0.035
     5.3 Flexural Reinforcement
   for,     Mx- =185.83mm
                Mx+ = 256mm
                 My- =233 mm
                My+ =314.81 mm

b) Spacing required should be minimum of the following conditions
           1) Spacing Required
           2) 3 Times Effective Depth
           3) 300mm
For,      
Table 5.6
Design moments
A
B
C
Spacing provided mm
Mx-
300
300
185.83
180
Mx+
300
300
256
250
My-
270
300
233
230
My+
270
300
314.81
270

Table 5.7 No. of bars :- 
Desigm moments
No. of bars provoded 
Ast.(prov.) mm2
Mx-
6
471.24
Mx+
4
314.16
My-
5
392.69
My+
4
314.16

Table 5.8 %Pt:-
Desigm moments
%Pt
Fs
Modification factor
Mx-
0.47
215.87
1.42
Mx+
0.31
235.03
1.56
My-
0.44
206.58
1.6
My+
0.35
191.14
1.78

5.9 Check for Effective Depth (Typical and Terrace)
Table 5.10 Check for deflection (Typical and Terrace)
Design moments
L/d max
l/d (prov.)
Check
Mx-
36.92
31.88
Safe
Mx+
40.56
31.88
Safe
My-
41.6
40.67
Safe
My+
46.28
40.67
Safe

5.5 Deflection Check
The vertical deflection limits may generally be assumed to be satisfied, provided that the span to depth ratios are not greater than the max span to depth ratio.

5.6 Slab Detailing
5.6.1 Flexure Reinforcement
Bottom steel obtained from moment Mux+ and Muy+ should be uniformly distributed across the middle strip in short and long span directions respectively and to be provided up to 0.251 of a continuous edge and 0.151 of a discontinuous edge. It is also recommended that alternate bars should extend fully into the support.
Top steel obtained from moment Mux- and Muy- should be provided up to a distance of 0.151 and alternate bars up to 0.31 on either side of continuous support. At discontinuous edge tension reinforcement equal to 50 percent of that provided at mid span in same direction should be provided extending over a length of 0.11.
5.6.2 Torsional Reinforcement
Torsional Reinforcement is required at the corners of rectangular slab panels whose edges are discontinuous, it can be provided in form of mesh at top and bottom. Mesh should extend beyond the edge over a distance not less than one-fifth of the shorter span.

 


{If  you are unable to see all details in google document just download it an run it on MS office of your system it will be clear}