this presentation contain design philosophies as per IS Code and designs for structure designs in civil engineering

1. S.N.P.I.T. & R.C.,
UMRAKH
DESIGN PHILOSOPHY
- Professor Urvesh N.Barot
- Assis. Professor Keyur P. Shah
1S.N.P.I.T. & R.C.

2. Presentation by:
 Mehta Mrunali- 130490106064
 Modi Nagma- 130490106065
 Nakrani Akash- 130490106066
 Nikam Sejal- 130490106067
 Pansuriya Prashant- 130490106068
 Patel Akshar- 130490106071
2S.N.P.I.T. & R.C.

3. DESIGN PHILOSOPHY
The main buildings in the stadium complex are
the stands, members and player's pavilion block,
venue operating centre, media centre and
landscaped seating stand apart from service
buildings and underground structures.
The structural system adopted for the buildings
are concrete/structural steel framed conventional
beam slab and column structures on pile caps over
bored cast-in-situ concrete piles/pre-cast concrete
piles/green heart timber piles. The slabs are
proposed in composite construction with concrete
on profiled metal decking (serving as
reinforcement). The stands are designed with pre-
cast bleachers on raker beams in concrete/structural
steel
3S.N.P.I.T. & R.C.

4. . The roof covering the stands are designed with
structural steel elements in profiled sections to
match the architectural form. The columns in cast-
in-situ concrete/structural steel have insert
plates/base plates to seat the roof-supporting
member. The structures are analysed for dead
load, live load and wind loads as per the codal
provisions. Waterproofing on concrete surfaces
exposed to atmosphere is done with reinforced
modified bituminous membrane and is protected
by cement concrete tiles. The waterproofing of
sunken slabs in toilets is also achieved with the
same material. All structural steel surfaces are
protected from corrosion with anti-corrosive paint.
4S.N.P.I.T. & R.C.

5. SERVICEABILITY:
 It implies satisfactory performance of the structure
under service loads, without discomfort to the user due
ti excessive deflection, cracking, vibration and so on.
Other considerations that comes under the preview of
serviceability are durability, acoustic and thermal
insulation etc.
 The adverse effect of excessive deflections are:
1. it creates feeling of lack of safety
2. Asthetic view is spoiled.
3. Creates ponding of water on roof slabs
4. Cracking of floor finish materials
5. In machines, it result into misalignment of machines.
S.N.P.I.T. & R.C. 5

6. DESIGN LOADS
Dead Loads
The self weight of the various elements are computed
based on the unit weight of materials as given below:
Material Unit Weight kN/m3
Steel 78.5
Plain Cement Concrete 24
Reinforced Cement Concrete 25
Cement Concrete Screed 24
Soil 20
6S.N.P.I.T. & R.C.

7. Imposed Loads
As per BS:6399 (Part 1)-1996 the building is classified
as Public Assembly building.
The superimposed loads or otherwise live load is
assessed based on the occupancy classification as
per BS:6399(Part 1)-1996 for assembly building. The
imposed loads (in kN/m2) considered are as listed
below:
7S.N.P.I.T. & R.C.

8. Occupancy Classification Load (kN/m2
)
a) Assembly areas:
1) with fixed seats 4.0
2) without fixed seats 5.0
b) Kitchens, laundries 3.0
c) Stages 7.5
d) Corridors, hallways, stairs 4.0
e) Dressing rooms 2.0
f) Areas for equipment 2.0
g) Toilets and bathrooms 2.0
8S.N.P.I.T. & R.C.

9. On flat roofs, sloping roofs and curved roofs with
slopes up to and including 10 degrees, the imposed
loads due to use or occupancy of the buildings and the
geometry of the roofs are given below:
As per cl 6.2, BS:6399 (Part 1)-1996
a) For roofs with access provision 1.5
b) For roofs without access provision 0.75
On sloping roof of slope greater than 10o, as per
clause 6.3 of BS:6399(Part1)-1996 the imposed loads
(kN/m2 of the plan area) that are likely to act
permanently are as follows:
Waterproofing* 1.5 (On roof / terrace)
Partitions 1.0 (wherever applicable)
False ceiling 0.5 wherever applicable)
9S.N.P.I.T. & R.C.

10. Structural slab shall be sloped suitably to avoid
achieving requisite slopes with screed/brick bat coba
Bleachers are designed to resist a horizontal force
applied to seats of 3.0 kN per linear meter along the
line of seats and 1.5 kN per linear meter perpendicular
to the line of seats.
10S.N.P.I.T. & R.C.

11. Wind Load
The wind pressure is calculated based on the data
furnished below and as per the provisions laid in
BS:6399 (Part 2)-1997
Basic Wind speed = 50m/sec
(As assessed from UBC)
Maximum gust = 30mph
(13.5m/sec) As given
Mean probable = 50 years
11S.N.P.I.T. & R.C.

12. DESIGN LIFE OF STRUCTURE
Building Type factor Kb = 1.0
Ground roughness category = town
Built up areas with an average level of roof tops at
least Ho =5m above GL
Dynamic Augmentation Factor Cr
=0.03
12S.N.P.I.T. & R.C.

13. Static Simplified method is used for design for
wind loads with the following parameters as per cl
2.2 BS:6399 (Part2)-1997
Directional Factor Sd = 1.0
Altitude Factor Sa = 1.0
Seasonal Factor Ss = 1.0
Probability Factor Sp = 1.0
Site Wind Speed Vs = Vb x Sa x Sd x Ss x Sp
= 50 x 1 x 1 x 1 x 1 x 1 = 50m/sec
Effective Wind Speed = Vs x Sb
Where Sb is the terrain and building factor
obtained from cl 2.2.3.3 of BS:6399(Part2)-1997
13S.N.P.I.T. & R.C.

14. Earthquake Load
Guyana is not within the earthquake belts and also
does not figure in the places listed in the
seismological active zones. It has been mentioned
that Guyana experiences tremors every 5-10 years.
Earthquake loads are not considered for analysis and
design. With the given conditions it is assumed that
the wind load on the structure would be sufficient
for the lateral loads that would be generated during
the tremors.
14S.N.P.I.T. & R.C.

15. Structural
Codes Description
Indian Standards
IS: 456-2000 Code of Practice for Plain and Reinforced Concrete
IS: 800-1984 Code of Practice for General Construction in Steel
IS: 808-1989 Dimensions for hot rolled steel beams, columns,
channels and angle sections
IS:875-1987(Part-1) Code of Practice for Design Loads (Other than
Earthquakes) for Buildings and Structures.
Dead Loads — Unit Weights of Building Materials
and Stored Materials
IS:875-1987(Part-2) Code of Practice for Design Loads (Other than
Earthquakes) for Buildings and Structures.
Imposed Loads
IS:875-1987(Part-3) Code of Practice for Design Loads (Other than
Earthquakes) for Buildings and Structures.
Wind Loads 15S.N.P.I.T. & R.C.

16. Codes Description
Indian Standards
IS:875-1987(Part-5) Code of Practice for Design Loads (Other than
Earthquakes) for Buildings and Structures.
Special Loads and Load Combinations
IS:1786-1985 Specification for High Strength Deformed Steel
Bars and Wires for Concrete Reinforcement.
16S.N.P.I.T. & R.C.

17. Design process: analysis, design
and detailing:
 Analysis:
Structural analysis is necessary to determine the
stress resultant like,
1. Shear stress
2. Bending moment
3. Axial force
4. Torsional moment
Acting at various cross sections of structural
elements. IS:456 permits the analysis of all
structures by linear elastic theory. Code also
permit use of approximate methods like
substitute frame method, use of coefficients for
the continuous beams and slabs.
For the analysis of statically determinate
beams and frames, conditions of static
equllibrium 17S.N.P.I.T. & R.C.

18. Structural analysis: modelling
18S.N.P.I.T. & R.C.

19.  Design:
A systematically planned structure:
1. Should satisfy the functional requirements of the
client and should be asthetic, which needs an
architect.
2. Should be structurally safe so as to withstand the
loads it has to bear, which needs a structure
engineer.
The functional design of the building consists of
planning the areas in best possible ways to obtain
maximum usage and functions from the building.
For a given residential bunglow,
19S.N.P.I.T. & R.C.

20. Functional planning
20S.N.P.I.T. & R.C.

21.  The structural design is concerned with the
strength of the building and its components. The
aim of structural design is to decide the size of the
member and provide appropriate reinforcements
so that the structures being designed will perform
satisfactorily during their intended life.
 With the appropriate degree of safety, the structure
should:
1. Sustain all loads
2. Sustain the deformation during and after
construction
3. Should have adequate durability
4. Should have adequate resistance to misuse and
fire
21S.N.P.I.T. & R.C.

22. Structural planning
22S.N.P.I.T. & R.C.

23.  Detailing:
On completion of the structural design, the design
ideas normally need to be communicated for
construction at the site by translating them into
detailed structural and comprehensive. In fact, an
elaborate analysis becomes worthless if the
computations are not translated effectively into the
structural drawings.
Two main aims of RCC detailing are:
1. Providing an outline of the concrete to give
necessary information regarding formwork to
provide finished section of the desired size.
2. Providing enough reinforcement details for
fabrication of the steel skeleton and its placement
in the desired position.
23S.N.P.I.T. & R.C.

24. Detailing
24S.N.P.I.T. & R.C.

25. Limit state method
 In this method of design, the structure shall be
designed to withstand safety all loads liable to
act on it throughout its life. It shall also safety
the serviceability requirements, such as
limitations on deflection and cracking.
 The aim of design is to achieve acceptable
probabilities that the structure will not become
unfit for use for which it is intended, that is, that
it will not reach a limit state.
 All relevent limit state shall be considered in
designed to ensure an adequate degree of
safety and serviceability. In general, the
structure shall be designed for the most critical
limit state and shall be checked for the other
limit states. 25S.N.P.I.T. & R.C.

26.  The limit state design philosophy, uses a multiple
safety factor format, which attempts to provide
adequate safety at ultimate loads as well as
adequate serviceability at service loads, by
considering all possible limit states.
 For ensuring the above objectives, the design
should be based on characteristics values for
material strengths and applied loads, which takes
into account the variation in the material strength
and in the loads to be supported.
26S.N.P.I.T. & R.C.

27. 27
Serviceability Limit States:
• Cracking
• Excessive Deflection
• Buckling
• Stability
Limit States
S.N.P.I.T. & R.C.

28. Working stress method:
 This is the traditional method of design, used not
only reinforced concrete but also for structural steel
and timber. This method of design was evolved
around the year 1900. this method was accepted
by many national codes. This method is based on
linear elastic method.
 This method ensures adequate safety by suitably
restricting the stresses in the materials induced by
the expected working loads on the structure.
 In this method it is assumed that concrete and steel
are elastic. At the worst combination of working
loads, the stresses in materials are not exceeded
beyond permissible values.
28S.N.P.I.T. & R.C.

29.  The permissible stresses are found out by using a
suitable factor of safety to material strength, e.g.
for concrete in compression due to bending, a
factor of safety equal to 3.0 is considered on 28
days. Characteristic strength and factor of safety
equal to 1.8 is considered on the yeild strength for
mild steel reinforcement in tension due to bending.
 Working stress method does not consider the mode
of failure of the structure . Also, the reserve
strength of materials beyond yield point is not
considered in this method of design.
 The WSM assumes strain compatibility, whereby
the strain the reinforcing steel is assumed to be
equal to that in the adjoining concrete to which it is
bonded.
29S.N.P.I.T. & R.C.

30. Demerits of WSM:
 The WSM does not show the real strength nor gives
the true factor of safety the structure under failure.
 Because of creep and non linear stress- strain
relationship , concrete does not have definite
modulus of elasticity.
 It assumes stress-strain relationship for concrete is
constant, which is not true
 WSM does not consider the mode of failure of the
structure i.e. ductile or brittle.
 It give large sections of structural elements, thus
uneconomical.
30S.N.P.I.T. & R.C.

31. Merits of WSM:
 It is simple, both in concept as well as in
application.
 The design usually results in large sections of
structural members, compared to LSM. Due to this,
structures designed by WSM give better
serviceability performance. i.e., less deflection, less
crack width etc.
 It is reasonably reliable.
31S.N.P.I.T. & R.C.

32. 32S.N.P.I.T. & R.C.