DESIGN BASIS REPORT
RESIDENTIAL BULDING AT ADHERI EKTA, MUMBAI
STRUCRURAL DESIGN BASIS REPORT
SUBMMITING ENGINEER - PALLAV BISEN
Page | 1
DESIGN BASIS REPORT
Table of Contents
Foreword .......................................................................................................................................3
Project Description.........................................................................................................................3
Architectural floor plan .................................................................................................................4
Structural floor plan .......................................................................................................................7
List of Code....................................................................................................................................9
Deign parameter.............................................................................................................................11
Software input data in Etabs .........................................................................................................12
Loading parameter .......................................................................................................................13
Load calculation ............................................................................................................................16
Risk indicators ...............................................................................................................................24
Stability check ..............................................................................................................................28
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DESIGN BASIS REPORT
Foreword
This report covers the minimum design requirement to establish the unified design basis that will
form the overall design philosophy to be adopted in the structural design of the building.
The design will aim to achieve.
Structural & functional integrity.
Desirable Structural performance under characteristic service design loads.
Resistance to loads due to natural phenomena Like Wind and earthquakes.
Structural durability & maintainability.
Project Description
Project
: G+12 RESIDENTAIL BUILDING
Location
: ADHERI EKTA, Mumbai.
Structural Floor
: Stack Parking floor + Ground Floor +11 Typical Floor + Terrace +
OHT&LMR
Project Information Data
Specific requirements of a floor like habitual, sinking, kitchen and toilet area for services. External
architectural features, and entrance canopies will be provided as required by architects. The
relevant information will be obtained from them in the form of drawings.
Lift loads and lift machine room equipment and cutout layouts will be obtained from the lift
manufacturers. An impact factor will be considered in the lift supporting structures.
Soil report provided by geotechnical constants.
Site Environment Data
Average weather data:
Temperature: Max 45˚c
Min 15˚c
Wind direction & basic wind pressure: As per IS 875 (Part III)
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DESIGN BASIS REPORT
Seismic Data
: As per IS 1893-2016
Rainfall: Rainy season: June to October.
Avg. Annual rainfall ----2000 mm.
Max Rainfall ----150mm.In 24Hrs
Architectural Floor Plan
Ground Floor Plan
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DESIGN BASIS REPORT
First Floor Plan
7th To 10th Floor Plan
Page | 5
DESIGN BASIS REPORT
11th Floor Plan
Terrace Floor Plan
Page | 6
DESIGN BASIS REPORT
Structural Floor Plan
Ground Floor Plan
IST Floor Plan
Page | 7
DESIGN BASIS REPORT
Typical Floor Plan
7th to 10th floor plan
Page | 8
DESIGN BASIS REPORT
Terrace floor plan
List of Code
Design Load (Other Than Earthquake)
IS Code
IS 875(Part 1): 1987
IS 875(Part 2): 1987
IS 875(Part 3): 1987
Description
Dead Loads - Unit Weight of Building Material
and Stored Material
Imposed Loads
Wind Loads
Design for Earthquake Resistance
IS Code
IS 1893:2002
IS 4326: 1993
IS 13920: 1993
Description
Criteria for earthquake resistance design of
structures.
Earthquake Resistant Design and Construction
of Buildings – Code of Practice
Ductile Detailing of Reinforced Concrete
Structures Subjected to Seismic Forces - Code
of Practice.
Page | 9
DESIGN BASIS REPORT
Design of plain and RCC Concrete Element
IS Code.
Description.
IS 456: 2000
Plain and Reinforced Concrete - Code of practice
Structural use of concrete. Design charts for
singly reinforced beams doubly reinforced
beams and columns.
Handbook on Concrete Reinforcement &
Detailing
Indian Standard Code of practice for design &
construction foundations in Soil: General
Requirements
Indian Standard Code of Practice for Design and
Construction of Raft Foundation (Part – 1)
SP 16
SP 34
IS 1904
IS 2950
Proposed Approach of Structural Analysis
The building is an R.C.C shear wall/columns and beam, slab frame structure.
After preliminary sizing of various structural members, computer model of the structural frame of
the building will be generated for carrying out computer analysis for the effects of vertical and
lateral load that are likely to be imposed on the structure.
The building structure will be analyzed using the ETABS software.
Geometrical dimensions, member properties, and member-node connectivity, including
eccentricities, will be modeled in the analysis problem. Variation in material grades, if present,
will also be considered.
Wind load derivations will be carried out using gust factor method in accordance with the relevant
codes.
The seismic loads will be derived from the results of dynamic analysis of the structure in
accordance with the relevant code of practice.
The permissible values of the load factors and stresses will be utilized within the purview of the
Indian Standards.
The computer analysis will evaluate individual internal member forces, reactions at foundation
level and deflection pattern of the entire structure and in the individual members. This data will
then be used to verify the adequacy of the member sizes adopted and after further iterations arrive
at the most appropriate design of the structural members. Some re-runs of the analysis program
Page | 10
DESIGN BASIS REPORT
might be required for arriving at the optimum structural space frame characteristics that satisfy the
strength and stability criteria in all respects.
Space frame analysis will be carried out for gravity loads, wind loads and seismic load.
Design Parameters
For the design of R.C.C. elements, the Limit State Method will be used as per IS 456-2000.
The building is RCC frame structure with columns shear walls/cores; floor slabs being used as
diaphragms in redistribution of lateral forces.
The minimum Grade of Concrete in all RCC structural members beam and slab shall be M 25
The Grade of Concrete in RCC shear wall shall be M 30
The concrete of Grade M20 shall be used in filling, plain concrete, leveling courses and other nonstructural items.
The density of reinforced concrete is assumed as 25 kN/m3
Minimum cement content, water cement ratio etc. shall conform to IS 456:2000 provisions for
durability and strength criteria.
High Yield Strength Deformed bars conforming to IS: 1786 with Fy = 500MPa
Covers to reinforcement shall be in accordance with IS: 456:2000 corresponding to moderate
exposure conditions for the super-structure or severe exposure conditions for the sub-structure and
to satisfy a fire rating of 2 hrs.
Value Engineering Exercises
In order to optimize the material consumption, sample analysis and design exercises have been
undertaken with different combinations of member sizes and the required reinforcement and
formwork will be estimated. Results of these exercises have been considered in arriving at the
structural scheme of the building.
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DESIGN BASIS REPORT
Software Input Data in Etabs model
Section Used For Framing Structure
Slab
Slab 150mm thickness – for habitual floor (Indication pink color)
Slab 125 mm thickness - For habitual floors (Indication brown color)
Slab 200mm thickness - For staircase (Indication blue color)
Slab 200mm thickness - For water tank and lift machine room (Indication green color)
Slab 200 mm thickness - For sunk slab (Indication blue yellow)
Beam
B150X300 - Secondary Beam (Indication green yellow)
B230x600 - Primary Beams (Indication red yellow)
Shear Wall
300 mm Thickness (Indication blue yellow)
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DESIGN BASIS REPORT
Support
Fixed Support translation x, y, z axis and rotation about x, y, z axis restraints.
Loading parameters
Self-Weights
Self-weight of the structural members will be considered on the basis of the following properties.
Density of reinforced concrete
Density of plain concrete
Density of steel
Density of floor finishes/plasters
Density of soil
Density of light weight concrete blocks
Plastering / Screeds
Cementitious water proofing
25 KN/m3
24 KN/m3
78.5 KN/m3
21 KN/m3
18 KN/m3
10 KN/m3
21 KN/m3
2.0 KN/m3
(As per IS code 875-part 1)
Dead load (DL):
Dead load including self-weight of various materials & finished items relevant to the design work
and shall be considered as per IS: 875 (Part I). Suspended loads if any such as cable tray, piping
& lighting fixtures shall also be considered as dead loads.
Imposed Gravity Loads on floors
The loads assumed are not imposed by the intended use of occupancy of a building including the
weight of movable partitions, distributed/concentrated loads, loads due to impact & vibrations &
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DESIGN BASIS REPORT
dust load etc. shall be considered. These loads are assumed only for the purpose for study and
comparison for the more effective model of the structure.
(AS per IS 875-2015 Part-2 clause 3.1 Table 1, Table 2)
Load Component
Fitness Centre Slab
Dead load
Live load
UDL (kN/m2)
Load Component
Canopy slab
Dead load
Live load
UDL (kN/m2)
Load Component
FRD Slab
Dead load
Live load
UDL (kN/m2)
Load Component
Stack parking
maintains slab
Dead load
Live load
UDL (kN/m2)
Load Component
Habitual Slab
Dead load
Live load
UDL (kN/m2)
Load Component
Lift Slab
Dead load
Live load
UDL (kN/m2)
1.5
4
1.5
0.75
1.5
3
1.5
1.5
1.5
2
10
0.75
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DESIGN BASIS REPORT
Load Component
Lobby Slab
Dead load
Live load
UDL (kN/m2)
Load Component
Security office Slab
Dead load
Live load
UDL (kN/m2)
Load Component
OHT Slab
Dead load
Live load
UDL (kN/m2)
Load Component
Refuge Slab
Dead load
Live load
UDL (kN/m2)
Load Component
Service Slab
Dead load
Live load
UDL (kN/m2)
Load Component
Staircase
Dead load
Live load
UDL (kN/m2)
Load Component
Terrace slab
Dead load
Live load
UDL (kN/m2)
1.5
3
1.5
3
35
0.75
1.5
5
1.5
1.5
3
3
3
2
Load Component
UDL (kN/m2)
Sunk slab or toilet
slab
Dead load
3
Live load
2
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DESIGN BASIS REPORT
Load calculation
Sunk slab load calculation
Dead load = light weight filling material + floor finish
Light weight filling material = thickness of filling x density of material
=0.15 x 8
=1.2 kN/m2
Floor finish = (density of cement motor x thickness of cement motor + density of tiles x
Thickness of tiles + density of plaster x thickness of plaster)
= 0.025x21+0.025x23+0.015x21
=1.2+0.525+0.575+0.315
=1.4 kN/m2
Dead load = 1.2+1.4
=2.6 kN/m2
=3 kN/m2 Approx.
(As per IS 875-2015 Part 1 All material density Taken)
Water Tank load calculation
Flat no in floor = Typical floor 9 having no of flat 4
= Floor 10 th having no of flat 3
=Floor 11 th having no. of flat 2
Total no. of flat =9x4+3+2
=41
Considering no of persons in each flat is 5
So total no. of person in building 41x5=205
Required water for 205 persons =135x205=27675 liters of one day
(Considering 135 LPCD from the UPPFI Guideline)
Considering 2 days of storage of water =2x27675=55350 liters
Therefore,
Volume of water tank =55350/1000= 55.35 m3
Deal load of water =55.35x1000=55350 kg
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DESIGN BASIS REPORT
Considering density of water 1000 kg/m3
Dead load of water in kN =0.00981x55350=542.985kN
Area of water tank supporting slab =16.33 m2
Deal load of water tank in kN/m2 =542.985/16.33=33.25 kN/m2
So providing Dead load of water tank slab =35 kN/m2
Lift machine Room load calculation
Mechanical data for lift
Lift type = counter weight type
12 person capacity of lift
Passenger weight = 820 kg
Lift car weight =800 kg
Counter weight = 1620 kg
Impact factor = 2
(As per IS 875 part 2)
Total weight of lift core = (820+800+1620) x2
= 6480 kg
=64.8 kN
Total weight of Tow lift core = 2 x 64.8
=129.6
Area of slab supporting lift = 20.45
Dead load of lift = 129..6/20.45
= 6.32 kN/m2
=10 kN/m2 (Providing)
Wall load calculation
Thickness of wall x density of material x (floor to floor height – depth of beam)
Page | 17
DESIGN BASIS REPORT
External Wall Load Calculation = 0.15 x 10 x (2.9-0.6)
=3.45 KN/m
Internal Wall Load Calculation = 0.1 x 10 x (2.9-0.6)
= 2.3 KN/m2
Parapet Wall Load Calculation = 0.15 x 10 x 1.2
=1.8 KN/m2
Water Tank Wall Calculation
Volume of Tank = L x B x H
55.35 = 16.33 x H
H = 3.38 m
= 3.4 m
= 0.15 x 25 x 3.4 = 12.75 KN/m2
Water Tank Top cover slab load calculation
Total load of top cover slab of water tank =density of concrete x thickness of slab
=25x0.125
=3.125 kN/m2
Top cover slab of water tank having tow way action so the load transfer machines of nearby
element shown in figure
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DESIGN BASIS REPORT
`
Area of tringluer portion
B2 /4 = (3.22x3.22)/4
=2.59 m2
Load shared by triangular portion on beam
=2.59x3.125
=8.09 kN
Area of trapezoidal portion
= (B (2L-B))/4
= (3.22x (2x5.07-3.22))/4
=5.57 m2
Load shared by trapezoidal portion
=5.57x3.12
=17.40 kN
Load on beam
(Assumption 60% load shared by beam)
=60%x17.40
=10.44 kN
40% shared by shear wall
Wind load Calculation
AS per Is 875 part 3 clause 7 if the structure having frequency less than 0.1 then analysis done as
per gust factor method.
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DESIGN BASIS REPORT
Guest factor analysis is done for the structure.
Gust factor is defend as the ratio between peak wind gusts and mean wind speed over a period of
time, can be used along with other statistics to examine the structure of the wind. Gust factor are
heavily dependent on upstream terrain condition (roughness), but are also affected by transition
flow regimes,
Design wind speed Vz = Vb x K1 x K2 x K3
Vb Basic wind velocity for Mumbai= 44 m/s
(As per 875 2015 part 3 clause 6.2 annex A)
k1= 1
probability factor (Risk coefficient) for a design life of 50 years
(As per 875 2015 part 3 clause 6.3.1 table 1 (General building)
k2=Terrain roughness and height factor
(As per 875 2015 part 3 table 33)
Terrain category = 2 (Mumbai is located in coast near coast area with expose of building
few obstruction)
k3= 1
FLOORS
OHT&LMR
TERRACE
11
10
9
8
7
6
5
4
3
2
1
G
Topography factor
(As per Is 875 2015part 1 per 3 clause 6.3.3)
Fx
97.86
97.86
100.25
100.25
100.25
100.25
100.25
100.25
71.36
71.36
73.40
96.29
88.49
30.76
Table of wind load in x and y direction
Fy
240.70
240.70
246.60
246.60
246.60
246.60
246.60
246.60
175.42
175.42
180.46
236.75
217.56
75.64
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DESIGN BASIS REPORT
Earthquake load Calculation
Zone = III
(IS 1893-2016 Part 1 Fig. 1 seismic zone of India)
&
(IS 1893-2016 part 1 annex E)
Location: Mumbai city
Zone Factor = 0.16
(1893-2016 Part 1 Clause 6.4.2 Table 3)
Approximate Time Period Ta= (As per 1893-2016 part 1 clause 7.6.2)
Considering Building with infilled wall Panel
At X direction = 0.09h/√dx
=0.09 x 43.9 / √20.52
=0.872 Sec
At Y Direction = 0.09h/√dy
=0.09 x 23.3 / √17.65
=0.940 Sec
Importance Factor = 1.2 Building having occupancy more than 200.
(As per 1893-2016 part 1 clause 7.2.3 Table 8)
Response Reduction Factor= 5 RC building with special moment resisting fame (SMRF)
(As per 1893-2016 part 1 clause 7.2.6 table 9)
The Design Base Shear is given by
Vb = Z/2 x I/R x Sa/g,
(Per As 1893-2016 part 1 clause 6.4.2)
Where,
Z= Zone Factor
I = Importance Factor
R= Response Reduction Factor
Sa/g = horizontal acceleration coefficient
Page | 21
DESIGN BASIS REPORT
Design lateral force (As per 1893-2016 part 1 clause 7.2.1)
Vb = Ah.W,
Where,
Ah= Design horizontal acceleration spectrum value as per using the fundamental Natural period
Time period
W= Seismic weight of the building
Qi = Vb x Wihi2 / ∑Wjhj 2 (As per 1893-2016 part 1 clause 7.6.3)
Where,
Qi =Design lateral force at floor
Wi =Seismic weight of floor
Percentage of imposed load to be considered in seismic weight calculation
50% for live load grater then 3 KN/m2
(As per 1893 part 1 clause 7.3.1 table 10)
Dynamic analysis of space frame done by response spectrum method and scaling for static base
shear and dynamic base shear done as per IS 1893-2016 part 1 clause 7.7.3
Eccentricity ratio (applied to diaphragms other than torsional irregulaty) = 5 %
Since the structure is an R.C.C. structure a damping value of 5% will be considered
(As per is 1896 part 1 clause 7.2.4)
Temperature Load calculation
For terrace slab temperature load is considered. Temperature taken for the load is 30 C0 for slab
and beams.
Uniform temperature change =Maximum day time temperature – minimum night time temperature
=45 C0 – 15 C0 = 30 C0
Page | 22
DESIGN BASIS REPORT
Bending Moment Diagram
Shear Force Diagram
Page | 23
DESIGN BASIS REPORT
Axial Force Diagram
Risk Indicators
Orthogonal axis:
(Not consider)
When the local axis of column and shear wall are not parallel or perpendicular to the global x and
y direction. The structure is said to be structurally Irregular structural mathematical model is done
in such way that this Irregularity is not found because the vertical load carrying element in global
x and global y direction
P delta analysis: (Consider)
P-delta is secondary effect on shear forces and bending moment of lateral force resisting elements
generated under the action of vertical gravity loads interacting with the lateral displacement of
building resulting from the seismic effects.
This additional demand is in addition to the earthquake shear demands. Which means that if we
have not considered the P-delta demands and if we provided insufficient shear resistance, than the
building might get collapse? So it is beneficial to take the P-Delta effects while designing the
building.
Page | 24
DESIGN BASIS REPORT
Factor taken 1.5 for deal load in P delta analysis
Buckling analysis: (not consider)
But as per the analysis observation structure is more stable.
Height to width ration found to be
43.9/22.5=1.95
So ratio is less than 6 then not required for buckling analysis.
Stability of Structures
For the purpose of stability of the structure as a whole against overturning, the restoring moment
shall not be less than 1.2 times the maximum overturning moments due to dead load plus 1.4 times
the maximum overturning moments due to imposed loads. Especially for uplift of raft foundation
.In case where dead load provides the restoring moments only 0.9 times in dead load shall be
considered. The restoring moments due to imposed loads shall be ignored.
The factor of safety against sliding shall not be less than 1.40.
Factor of safety against buoyancy shall be not less than 1.20 ignoring the superimposed loading.
Torsional Irregularity Check
Building having torsion ally irregular when the ration of maximum horizontal displacement at one
end of floor is more than 1.2 times its average horizontal displacement at the far end of same floor
in that direction
(AS per UBC code)
Story Load
Directi Maxim Avera Rat Ax
Acc.
Wid Eccentr
Case/Co on
um
ge
io
Torsion th
icity
mbo
OHT& SPEX
X
15.314 14.58 1.0 0.7660 0.03830 5.47 0
LMR
Max
1
5
2
101
5
TERR SPEX
X
18.378 15.74 1.1 0.9464 0.04732 19.6 0
ACE
Max
2
67
86
43
2
8/11
SPEX
X
17.297 14.83 1.1 0.9439 0.04719 19.6 0
Max
6
66
42
711
2
10
SPEX
X
16.119 13.84 1.1 0.9407 0.04703 19.6 0
Max
9
64
56
779
2
9
SPEX
X
14.806 12.74 1.1 0.9377 0.04688 19.6 0
Max
1
62
91
954
2
Page | 25
DESIGN BASIS REPORT
8
7
6
5
4
3
2
1
G
FLOO
R
SPEX
Max
SPEX
Max
SPEX
Max
SPEX
Max
SPEX
Max
SPEX
Max
SPEX
Max
SPEX
Max
SPEX
Max
X
13.34
X
11.728
X
9.992
11.49
6
10.12
3
8.64
X
8.163
7.074
X
6.283
5.458
X
4.416
3.845
X
2.66
2.32
X
1.173
1.013
X
0.398
0.206
Load
Case/Comb
o
11
SPXY Max
Y
25.825
10
SPXY Max
Y
23.782
9
SPXY Max
Y
21.609
8
SPXY Max
Y
19.259
7
SPXY Max
Y
16.75
6
SPXY Max
Y
14.113
5
SPXY Max
Y
11.388
Aver
age
25.73
9
25.47
3
23.78
2
21.93
7
19.93
2
17.76
2
15.44
6
13.01
2
10.49
7
4
SPXY Max
Y
8.633
7.958
Story
OHT&
LMR
SPXY Max
TERRA
CE
SPXY Max
Direct Maxi
ion
mum
Y
27.585
Y
27.79
1.1
6
1.1
59
1.1
56
1.1
54
1.1
51
1.1
49
1.1
47
1.1
58
1.9
33
Rat
io
1.0
72
1.0
91
1.0
86
1.0
84
1.0
84
1.0
84
1.0
84
1.0
85
1.0
85
1.0
85
0.9350
95
0.9321
1
0.9287
84
0.9247
13
0.9202
47
0.9160
16
0.9129
03
0.9311
39
2.5922
04
0.04675
474
0.04660
548
0.04643
922
0.04623
565
0.04601
237
0.04580
079
0.04564
517
0.04655
696
0.12961
021
19.6
2
19.6
2
19.6
2
19.6
2
19.6
2
19.6
2
19.6
2
19.6
2
17.6
59
Ax
0.797
628
0.826
522
0.818
882
0.816
168
0.816
216
0.816
434
0.816
648
0.816
936
0.817
339
0.817
247
Acc.
Torsion
0.03988
138
0.04132
61
0.04094
411
0.04080
842
0.04081
08
0.04082
172
0.04083
242
0.04084
68
0.04086
693
0.04086
233
widt
h
11.5
2
21.5
098
22.4
398
22.4
398
22.4
398
22.4
398
22.4
398
22.4
398
22.4
398
22.4
398
0
0
0
0
0
0
0
0
2.28878
671
Eccentr
icity
0
0
0
0
0
0
0
0
0
0
Page | 26
DESIGN BASIS REPORT
3
SPXY Max
Y
5.938
5.48
2
SPXY Max
Y
3.449
3.197
1
SPXY Max
G
FLOOR SPXY Max
Y
1.453
1.36
Y
0.589
0.325
1.0
84
1.0
79
1.0
68
1.8
15
0.815
374
0.808
237
0.792
667
2.280
874
0.04076
869
0.04041
184
0.03963
336
0.11404
372
22.4
398
22.4
398
22.4
398
19.4
25
0
0
0
2.21529
929
Soft Story stiffness check
If soft story is a whose lateral strength is less than that of story above
Percentage of Stiffness of below story –stiffness of present story /stiffness of below story
If it is more than 70% then the story is soft story
(As per 16700-2016 clause5.3)
Story
Load Case Stiffness
Soft story
OHT&LMR SPEX
162519.612 48.33
TERRACE SPEX
314575.658 36.44
11
SPEX
494997.883 18.14
10
SPEX
604759.554 10.23
9
SPEX
667463.913 5.7
8
SPEX
709423.485 4.67
7
SPEX
744214.12
3.8
6
SPEX
778572.33
6.09
5
SPEX
820149.643 5.74
4
SPEX
879264.94
11.22
3
SPEX
980660.049 11.22
2
SPEX
1209531.58 38.6
1
SPEX
1970007.837 82.79
G FLOOR
SPEX
7031432.001 27.08
SP
SPEX
9677313.993 Stable
Story
OHT&LMR
TERRACE
11
10
9
8
Load Case
SPXY
SPXY
SPXY
SPXY
SPXY
SPXY
Stiffness
92349.751
184532.086
276389.44
331351.901
365895.324
391245.426
Soft story
49.95
33.23
18.18
9.09
7.69
4.87
Page | 27
DESIGN BASIS REPORT
7
6
5
4
3
2
1
G FLOOR
SP
SPXY
SPXY
SPXY
SPXY
SPXY
SPXY
SPXY
SPXY
SPXY
414821.05
441429.515
476058.179
525179.606
601010.616
764950.075
1378442.672
6525677.307
10227076.91
6.81
6.83
9.6
13.33
21.05
44
78.87
36.19
Construction sequence analysis (consider)
Construction sequence analysis required to be performed for the building having non-uniformly
distributed vertical stiffness and also in case of building having floating column and transfer girder.
In this project need to be consider building having non- uniformly distributed vertical stiffness
Creep analysis (consider)
In this project deflection in serviceability model deflection criteria is not stratified the need for
creep analysis
Ritz vector used in model analysis
For missing model participating added its more realistic result. Model participating ration more
the 90%
Stability Checks
Maximum allowable Deflection in analysis
Maximum deflection against cantilever or any individual element allowed span/350 or 20mm
=Span /350
=6575/ 350
= 18.78 mm (allowable)
Deflection in slab- deflection in column
= 9.217-3.621
= 5.596
Actual deflection due to creep
= 16.788 (deflection in building)
Page | 28
DESIGN BASIS REPORT
Check
Deflection
Calculations
6575/350
Values
16.78
Limits
18.78
Modal Analysis
Mode
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Period
1.52
1.347
1.019
0.401
0.379
0.306
0.219
0.198
0.172
0.164
0.15
0.135
0.12
0.115
0.109
0.104
0.097
0.087
0.084
0.079
0.072
0.066
0.062
0.06
0.047
0.034
0.03
0.027
0.022
0.021
Sum UX
0.0025
0.0227
0.6877
0.6887
0.6922
0.8006
0.8007
0.8014
0.8112
0.8449
0.845
0.8462
0.8476
0.8533
0.8643
0.8716
0.8749
0.8774
0.8777
0.8866
0.8868
0.8869
0.9047
0.9073
0.9113
0.9119
0.9463
0.9468
0.9713
0.9717
Sum UY
0.6674
0.6684
0.6705
0.7902
0.7946
0.7948
0.8294
0.8332
0.8434
0.8468
0.8633
0.8633
0.864
0.8789
0.8946
0.8959
0.8966
0.8986
0.9206
0.9207
0.9207
0.9256
0.9264
0.9329
0.9338
0.9485
0.9486
0.9568
0.957
0.9869
RZ
0.0002
0.6259
0.019
0.0033
0.1181
0.0035
0.0015
0.0309
0.0091
0.0054
0.0047
0.001
0.0184
0.0024
0.0000319
0.0069
0.0001
0.0149
0
0.003
0.0004
0.0036
0.0018
0.0102
0.0024
0.0118
0.0004
0.054
0.0076
0.001
Sum RX
0.3599
0.3603
0.362
0.5826
0.5902
0.5909
0.6263
0.6301
0.6448
0.6495
0.6774
0.6774
0.6789
0.7059
0.7339
0.7358
0.737
0.7426
0.7914
0.7915
0.7923
0.8053
0.8067
0.8193
0.8212
0.8497
0.8499
0.8671
0.8676
0.9563
Sum RY
0.0015
0.0122
0.3438
0.3454
0.3514
0.5925
0.5928
0.5936
0.605
0.6432
0.6433
0.6472
0.6493
0.6607
0.6809
0.6929
0.7003
0.7041
0.7045
0.7192
0.7195
0.7195
0.7535
0.7582
0.7694
0.7712
0.8411
0.8429
0.9157
0.9168
Sum RZ
0.0002
0.626
0.6451
0.6483
0.7664
0.7698
0.7713
0.8022
0.8114
0.8168
0.8215
0.8225
0.8408
0.8433
0.8433
0.8502
0.8503
0.8653
0.8653
0.8683
0.8687
0.8723
0.8741
0.8843
0.8867
0.8985
0.8989
0.9529
0.9605
0.9615
Page | 29
DESIGN BASIS REPORT
The time period of the 1st mode of the translation is 1.52 sec.
Rz valve in first mode is 0.2% < 5%. The 1st mode is not torsional.
The first mode of the building is in translation mode. So total mass of the building participated in
X direction is 97.17% & in Y direction 98.69% achieving which is greater than 90% according
to IS1893:2016 table 6
The first three modes contribute at least 65 % mass participation factor in each principal plan
direction
(As per IS 1893: 2016 table 6)
Sum of Ux fires three mode =68.77
Sum of Uy first three mode =67.05
The fundamental lateral natural periods of the building in tow principal plan direction are away
from each other by at least 10 %
As per IS1893:2016 table 6
(1.52-1.347) x100 = 17.3%
The natural period of fundamental torsional mode of vibration shall not exceed 0.9 times the
natural period of the fundamental translation mode of vibration as per IS 16700:2017 clause 5.5.1
Time period of torsional mode = 1.347
Time period of fundamental mode = 1.52
= 0.9x1.52
= 1.368 >1.347 (time period of torsional mode)
Maximum story displacement in a Seismic analysis
Maximum story displacement due to seismic load is 21.16 mm in X-Direction. According to IS
16700-2017 clause 5.4.1 allowable displacement is (H/250) 178 mm.
Maximum story displacement due to seismic load is 26.94 mm in Y-Direction. According to IS
16700-2017 clause 5.4.1 allowable displacement is (H/250) 178 mm.
Page | 30
DESIGN BASIS REPORT
Check
Story displacement X
Story displacement Y
Values
21.16
26.94
Limits
178
178
Page | 31
DESIGN BASIS REPORT
Maximum allowable displacement in Wind analysis
Maximum story displacement occurred due to wind load which is 10.34 mm in X-Direction.
According to IS 456:2000 allowable displacement is (H/500) 89 mm.
Maximum story displacement occurred due to wind load is 48.80 mm in Y-Direction. According
to IS 456:2000 allowable displacement is (H/500) 89 mm
.
Check
Story displacement X
Story displacement Y
Values
10.34
48.80
Limits
89
89
Page | 32
DESIGN BASIS REPORT
Maximum allowable drift for Seismic analysis:
Maximum story drift occurred in X-direction due to Seismic load is 0.000749. This story drift is
less than allowable story drift which is 0.004 x story height 2.9 = 0.0116 according to
IS1893:2016.
Maximum story drift occurred in Y-direction due to Seismic load is. This story drift is less than
allowable story drift which is 0.004x story height 2.9 = 0.0116 according to IS1893:2016
Page | 33
DESIGN BASIS REPORT
Check
Story drift X
Story drift Y
Values
0.000749
0.000987
Limits
0.0116
0.0116
Maximum story shears due to seismic and wind analysis:
Story shear
Direction x
Direction y
Seismic
1612.93
1493.02
Wind
1245.18
1394.027
Here, Earthquake base shear is more governing than wind base shear.
Load Combination
The results obtained from the computer analysis in the form of member forces and reactions will
be used for design the structural members. Following load combinations of the member forces will
be considered for arriving at the design forces.
For dead
1.5 D
For dead and live 1.5 D + 1.5 L
load
For wind load
In x direction
1.5D + 1.5 Wx
For wind load
In y direction
1.5D + 1.5 Wy
1.5D -1.5 Wx
1.5D -1.5 Wy
1.5D + 1.5 Wx
1.5D + 1.5 Wy
0.9D + 1.5 Wx
0.9D + 1.5 Wy
0.9D - 1.5 Wx
0.9D - 1.5 Wy
1.2 D +1.2 L + 1.2
Wx
1.2 D +1.2 L + 1.2 Wy
1.2 D +1.2 L -1.2
Wx
1.2 D +1.2 L -1.2 Wy
Page | 34
DESIGN BASIS REPORT
For Earthquake 1.5D + 1.5 Spex
load
In x
direction
For Earthquake load 1.5D + 1.5 Spey
In y direction
0.9D + 1.5 Spex
0.9D + 1.5 Spey
1.2 D +1.2 L + 1.2
Spex
1.2 D +1.2 L + 1.2 Spey
Load combination for Soft story
For Earthquake 1.5D + 2.5 Spex
load
In x
direction
For Earthquake load 1.5D + 1.5 Spey
In y direction
0.9D + 2.5 Spex
0.9D + 2.5 Spey
1.2 D +1.2 L +
2.5Spex
1.2 D +1.2 L + 2.5 Spey
The fundamental translation lateral natural period in any of the horizontal plan direction, shall not
exceed 8 sec, considering sectional properties as per table 6 16700-2016 considering serviceability
model
(AS per clause 5.5.2 16700-2016)
Stiffness Modification Factor
(As per IS 16700:2017 clause 7.2 table 6)
Serviceability model
Slab = 0.3 Ig
Beam = 0.5 Ig
Column = Ig
Shear wall = Ig
Beam
Cross- section (axial) 1
area
Shear area
direction
in
2 1
Column
Cross- section (axial) 1
area
Shear area
direction
in
2 1
Page | 35
DESIGN BASIS REPORT
Shear area
direction
3 1
in
0.5
Torsional constant
Shear area
direction
in
3 1
Torsional constant
1
Moment if inertia 0.5
about 2 axis =
Moment if inertia 1
about 2 axis =
inertia 0.5
Moment of inertia 1
about 3 axis
Moment of
about 3 axis
Slab
Membrane
direction
f11 1
Shear wall
Membrane
direction
f11 1
Membrane
direction
f12 1
Membrane
direction
f12 1
Membrane
direction
f12 1
Membrane
direction
f12 1
Bending
direction
m11 0.3
Bending
direction
m11 1
Bending
direction
m22 0.3
Bending
direction
m22 1
Bending
direction
m12 0.3
Bending
direction
m11 1
Shear v13 direction
1
Shear v13 direction
1
Shear v23 direction
1
Shear v23 direction
1
Check of serviceability
1. Maximum deflection against cantilever or any individual element allowed span/350 or 20mm
Span /350
6575/350 = 18.78 mm or 20 mm (allowable)
Deflection in slab
Page | 36
DESIGN BASIS REPORT
=14.173 mm
Deflection is column
=4.562
Deflection in slab – axial in column
= 14.173-4.562
= 9.611
Actual deflection due to creep
= 3x 9.611= 28.833(deflection in building)
28.883>20mm (allowable)…………………………..Unsafe
Its valve is higher than limiting valve then it is unsafe then we have to go for material nonlinear
analysis. Creep
Serviceability criteria
Creep Analysis +Including P-delta +shrinkage+ Material Strength + Construction sequence
(As per CEB-FIP-94)
Page | 37
DESIGN BASIS REPORT
Strength Criteria
For Design
Construction sequence + P Delta analysis
Because bending moment more so achieving strength of building.
After design of all member check of rebar percentage for value engineering propose.
Maximum percentage of rebar in beam = 0.9 % > 4 %
Maximum percentage of rebar in shear wall = 1.432 % > 4 %
Hence satisfied criteria of value engineering.
Page | 38