Analysis & design of Multi storey RCC frame structure and comparision between NBC and IS code

1. ANALYSIS & DESIGN OF MULTI-STORY RCC
FRAME STRUCTURE AND COMPARISON
BETWEEN IS AND NBC CODES
Presented By :
Arjun Sigdel (1305)
Lochan Shrestha (1313)
Nirmal Dangi (1317)
Suman Gautam (1327)
Tek B. Nepali (1329)
BE (Civil-2013)
Group No:- 1
Asian Institute of Technology & Management (AITM)
(Khumaltar, Lalitpur, Nepal)
Department of Civil Engineering
January 7, 2018

2. Introduction
• Design of earthquake resistant multistory building
with medical purpose.
• Earthquake is the most destructive natural
phenomenon.
• The seismic design should be such that it prevents
loss of life and minimize the damage to the property
when earthquake occurs.
2

3. Rationale
• In 25 April 2015 Nepal rumbled
with a 7.8 magnitude
earthquake that killed 8,856,
injured 22,309 people and 956
hospitals were damaged.
Hospital should be functional
even after the disaster. So we
feel the importance to design
and analyze the hospital
building in final year project
3Source: www.dailymail.co.uk

4. Location of Study Area
• It is located at Basundhara, Kathmandu, which is
belongs to seismic risk zone A (NBC 105: 1994).
4Source: Google map

5. Building Description
Building Type Medical Building
Structural system RCC Space frame
Total land area 15255.24 Sq. ft (1417.27 Sq. m)
Plinth area covered 5680.45 Sq. ft (527.68 Sq. m)
No. of Story 5 and half story with basement
Floor Height 3.6 m
5

6. Objectives
1. Modeling of the building for structural analysis
2. Detail structural analysis using SAP 2000 V19
3. Design of structural components
4. Comparison of structural Analysis and Design
between IS and NBC codes
5. Structural detailing of members and the system
6. Estimation and costing of building
6

7. Limitations
• Architectural drawing has been provided.
• Bearing capacity of soil will be assumed because we are not
going to conduct the soil test.
• Structural detailing will be done only from NBC code result
• Design and layout of the building service like electrical, pipeline,
sanitary and sewage system will be out of the scope of the project.
• The environmental, social and economic condition will not be
taken into account.
7

8. LITERATURE REVIEW
BUILDING
• A building is a structure with a roof and walls standing
more or less permanently in one place.
• Buildings come in a variety of sizes, shapes and
functions.
8

9. SYSTEM OF BUILDING
CONSTRUCTION
1. Massive / Load Bearing masonry walls
• Those structure which carry the dead load, live load
in addition to its own weight.
• Such walls may be much thicker towards the base,
where maximum loads accumulate.
9

10. 2. Skeleton / Frame Structure
a. Steel frame structure
This type of building consists of a frame or skeleton of
steel, beam and column.
Characteristic of steel frame structure
• It is immensely strong.
• It has more flexibility.
• It has good ductility.
• It quickly loses its strength in a fire.
10

11. b. Concrete frame structure
• This type of building consists of a frame or skeleton of
concrete, beam, column and slab.
• Column is the most important member of the frame
structure.
• Column must be stronger then beam and slab.
• The skin can be made of brick, aluminum or glass, and
is attached to the outer surface of the building.
11

12. Advantages of concrete frame
structure
• It has a high compressive strength.
• It can also withstand a good amount of tensile stress.
• It is more durable.
• The maintenance cost of reinforced concrete is very low.
• It acts like a rigid member with minimum deflection.
12

13. Disadvantages of concrete frame
structure
• Casting cost is relatively higher.
• The compressive strength is lower in the case of RCC.
• Shrinkage causes crack development and strength loss.
13

14. Objectives of the RCC Structure
Design
• The structures so designed should have an acceptable
probability of performing satisfactorily during their
intended life.
• The designed structure should sustain all loads and
deform within limits for construction and use.
• The designed structures should be durable.
• The designed structures should adequately resist to the
effects of misuse and fire.
14

15. Design Loads and Forces
1. Dead loads
2. Imposed loads
3. Wind loads
4. Snow loads
5. Earthquake forces
6. Shrinkage, creep and temperature effects
7. Other forces and effects
15

16. Design Methods
Common Steps
• To assess the dead loads and other external loads and
forces likely to be applied on the structure.
• To determine the design loads from different
combinations of loads.
• To estimate structural responses due to the design
loads.
• To determine the cross-sectional areas of concrete
sections and amounts of reinforcement needed.
16

17. Types of Design Methods
• Working Stress design
• Ultimate load design
• Limit state design
• Performance based design
17

18. Working stress design
• Traditional method
• It assumes that the structural material behaves in
a linear elastic manner
• Permissible stresses of steel are kept well below
the actual strength
• It is deterministic approach
18

19. Drawbacks
• Concrete displays inelastic behavior even under very
low stress.
• This method fails to provide a uniform overload
capacity for the structure.
• It is difficult to incorporate the effects of shrinkage and
creep in the working stress design method.
19

20. Ultimate Load Method
• More improved method.
• The nonlinear stress strain behavior of concrete was
considered.
• The safety is ensured by introducing load factor.
20

21. Merits
• The stress block parameters are defined by the actual
stress-strain curve.
• The calculated failure load matches with the
experimental results.
• It utilizes the reserve strength in plastic region.
• It takes ultimate strain as the failure criteria.
• The load causing collapse is taken as the limit of safety.
• The method allows selection of different load factors.
21

22. Demerits
• It totally neglects the serviceability criteria of deflection
and cracking.
• The uses of high strength deform bars affects in increase
of deflection and crack width.
• The effect on deflection due to creep and shrinkage is
neglected.
22

23. Limit State Method
• Acceptable limits for the safety and serviceability
requirements of the structure before failure occurs.
• It is probabilistic approach
Types of limit state method
1. limit state of collapse
2. limit state of serviceability
23

24. 24
Stress-Strain curve
Fig :- Stress-Strain curve for steel Fig :- Stress-Strain curve for concrete

25. Performance Based Design
• This concept describes the required and possessed
performance of a structure.
• Evaluated to ensure compliance with the agreed
objectives.
• Main performance objectives can be summarized as
follows:
1. Functionality
2. Serviceability
3. Strength
4. Economy
25

26. Factor Of Safety
• 𝐹𝑎𝑐𝑡𝑜𝑟 𝑜𝑓 𝑠𝑎𝑓𝑒𝑡𝑦 =
𝑦𝑒𝑖𝑙𝑑 𝑠𝑡𝑟𝑒𝑠𝑠
𝑤𝑜𝑟𝑘𝑖𝑛𝑔 𝑠𝑡𝑟𝑒𝑠𝑠
Partial safety factors
𝐷𝑒𝑠𝑖𝑔𝑛 𝑠𝑡𝑟𝑒𝑛𝑔𝑡ℎ 𝑜𝑓 𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙 𝑓𝑑 =
𝐶ℎ𝑎𝑟𝑎𝑐𝑡𝑒𝑟𝑖𝑠𝑡𝑖𝑐𝑠 𝑠𝑡𝑟𝑒𝑛𝑔𝑡ℎ 𝑜𝑓 𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙,𝑓
𝑃𝑎𝑟𝑡𝑖𝑎𝑙 𝑠𝑎𝑓𝑒𝑡𝑦 𝑓𝑎𝑐𝑡𝑜𝑟 𝑜𝑓 𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙, 𝛾 𝑚
26

27. Characteristics load
• The load which has a 95 percent probability of not
being exceeds during the life of the structure.
27
• Thestrength of material not more than 5 percent
of the test results are expected to fall.
Characteristics strength of
material

28. Analysis of Structure
• Structures when subjected to external loads (actions)
have internal reactions in individual members. As
a result, the structures develop internal stresses
and undergo deformations.
• For the purpose of seismic analysis, we SAP2000
V19used the structure analysis program.
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29. Comparative Analysis of Seismic
Codes of Nepal and India
• Nepal National Building Code (NBC 105: 1994)
a) Load combinations
• DL + 1.3 LL + 1.25 E
• 0.9 DL + 1.25 E
• DL + 1.3 SL + 1.25 E
b) Methods of analysis
• Seismic Coefficient Method
• Modal Response Spectrum Method
29

30. I. Seismic Coefficient
Method
1. Horizontal Seismic Base
Shear
V = Cd Wt
Cd =basic seismic coefficient for the
fundamental traditional period
Cd= CZIK
• Basic Seismic Coefficient (C)
30

31. Periods of Vibration
T1 = 0.085H3/4
for steel frames
T1 = 0.06 H3/4
for concrete frames
For other structures:
𝑻 𝟏 =
𝟎.𝟎𝟗𝑯
𝑫
Where,
H= Height of building in m,
D= Base dimension of the building at the plinth level in m
31

32. Seismic Zoning Factor (Z)
32

33. Importance Factor (I)
33
SN Type of Building Importance
Factor (I)
(a) Monumental Buildings 1.5
(b) Essential facilities that should remain functional
after an earthquake
1.5
(c) Distribution facilities for gas or petroleum products
in urban areas.
2.0
(d) Structures for the support or containment of
dangerous substances (such as acids, toxic
substances, etc.).
2.0
(e) Other structures 1.0

34. Structure Performance Factor (K)
34
Item Structural Type Minimum Detailing
Requirements
Structural
Performance
Factor, K
1.(a)
(b)
Ductile moment-
resisting frame
Must comply with the detailing for ductility requirements.
1.0
Frame as in 1(a) with
reinforced concrete
shear walls
For frames: as for 1(a).
Reinforced concrete shear walls must comply with appropriate
detailing for ductility requirements.
1.01
2.(a)
(b)
Frame as in 1(a) with
either steel bracing
members detailed for
ductility or reinforced
concrete infill panels
For frames: as for 1(a).
Steel bracing members must comply with the detailing for
ductility requirements NBC 111-94.
Reinforced concrete infill panels must comply with the
detailing requirements of NBC 109-94.
1.51.2
Frame as in 1(a) with
masonry infill’s
Must comply with the detailing for ductility requirements.
2.01.2

35. 2. Horizontal Seismic Forces
The horizontal seismic force at each level i shall be taken as:
Fi =V
𝑾𝒊𝒉𝒊
𝑾𝒊𝒉𝒊
where
V = Base shear,
Wi = seismic weight of floor I,
hi= Height of floor measured from base
35

36. • Indian Standard (IS 1893 Part-1: 2002)
Combination of load
1. 1.5(DL+IL)
2. 1.2(DL+IL±EL)
3. 1.5(DL±EL)
4. 0.9DL±1.5EL
Design Seismic Base Shear
VB = Ah W
Where,
Ah = Design horizontal acceleration spectrum value
W = seismic weight of a building
36

37. Design horizontal seismic coefficient Ah as per
Cl. 6.4.2
Ah =
𝑍𝐼 𝑆𝑎
2 𝑅 𝑔
Where,
Z = Zone factor
I = Importance factor
R = Response reduction factor
Sa/g = Average response acceleration coefficient
37

38. Calculation of seismic weight (W)
Floor loads (KN/ m2) Percentage of Imposed load
Up to and including 3.0 25
Above 3.0 50
Zone factor Z
38
Seismic zone II III IV V
Seismic
intensity
low Moderate Severe Very severe
Z 0.10 0.16 0.24 0.36

39. Importance factors, I
SI No. structure Importance factor
1
Important service and community buildings, such as
hospitals; schools; monumental structures;
emergency buildings like telephone exchange,
television stations, radio stations, railway stations, fire
station buildings; large community halls like cinemas,
assembly halls and subway stations, power stations
1.5
2
All others buildings
1.0
39

40. Response reduction factor R for building system
S.N Building system R
1. Ordinary RC moment- resisting frame
(OMRF)
3
2. Special RC moment resisting frame
(SMRF)
5
40

41. Calculation of Sa/g
41

42. Fundamental Natural period
Ta = 0.075 h 0.75 for RC frame building
Ta = 0.085h0.75 for steel frame building
For other structures:
𝑻 𝟏 =
𝟎.𝟎𝟗𝒉
𝒅
Where
h= Height of building in m,
d= Base dimension of the building at the plinth level in m,
42

43. Distribution of design force
Qi =
𝑾𝒊𝒉𝒊 𝟐
𝒋=𝟏
𝒏 𝑾𝒋𝒉𝒋 𝟐VB
where
Qi = Design lateral forces at floor I,
Wi = seismic weight of floor I,
hi= weight of floor measured from base
n= Number of storey in in the building is the number of levels at
which the measures are located
43

44. Methodology
44

45. Software’s
• MS Word
• Excel
• SAP2000 V19
• AutoCAD
• Gantt Project
45

46. Implementation Schedule
46

47. Bibliography
• Liang Qing Quan, Performance-Based Optimization of Structures_ Theory and
Applications, Spon Press, 2004
• Jain Ashok K., Reinforced Concrete (Limit State Design), Nem Chand & Bros., 2012
• Dr. Thapa Kamal b., Er. Dhakal Bharat B., Design of Reinforced concrete, Heritage
Publishers & Distributers Pvt. Ltd., 2017
• http://www.understandconstruction.com/concrete-frame-structures.html, 12/10/2017
• http://nptel.ac.in/courses/105105104/3, 12/10/2017
• https://civildigital.com/3-design-philosophies-ultimate-load, 12/15/2017
• http://time.com/3838989/nepal-earthquake-hospitals/ , 12/28/2017
• http://www.dailymail.co.uk/wires/ap/article-3551129/A-list-effects-Nepals- earthquake-1-
year-ago.html, 12/28/2017
• NBC: 105-1994, Seismic Design of Buildings in Nepal, 1994
• IS: 1893 (Part-1)-2002, Criteria for Earthquake Resistant Design of structures, 2002
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