Thạc Sĩ Seismic Evaluation of Reinforced Concrete Buildings

CERTIFICATE
​

This is to certify that the work presented in Thesis entitled “Seismic Evaluation of
Reinforced Concrete Buildings” submitted by Mr. Taranpreet Singh in partial
fulfillment of requirements for the award of degree of Masters of Engineering in Civil
(Structures) at Thapar Institute of Engineering & Technology (Deemed University),
Patiala, is an authentic record of student’s own work carried out under my supervision
and guidance. The matter embodied in thesis has not been submitted anywhere for award
of any other degree.

ABSTRACT
​

The Buildings, which appeared to be strong enough, may crumble like houses of
cards during earthquake and deficiencies may be exposed. Experience gain from the
recent earthquake of Bhuj, 2001 demonstrates that the most of buildings collapsed
were found deficient to meet out the requirements of the present day codes. Due to
wrong construction practices and ignorance for earthquake resistant design of
buildings in our country, most of the existing buildings are vulnerable to future
earthquakes. In light of these facts, it is imperative to seismically evaluate the existing
building with the present day knowledge to avoid the major destruction in the future
earthquakes. The Buildings found to be seismically deficient should be
retrofitted/strengthened.
The present study deals with the evaluation of R.C buildings using inelastic method
(Pushover Analysis). Capacity Curve, which is Load-Deformation Plot is the Output
of Pushover Analysis. As, Pushover Analysis is Non-Linear Static Analysis, so the
Load-Deformation Curve can be obtained from ANSYS. Finite Element Software
ANSYS 5.4 is used to perform the Non-Linear Static Pushover Analysis and
Cracking pattern can also be observed in ANSYS. Cracking Pattern provides the need
for Strengthening required for particular Elements. Firstly, a symmetrical building is
analysed using ANSYS for the procedure development as per ATC-40. Then, Seismic
Evaluation is performed on unsymmetrical building (L-shape), which is designed in
the first part as without considering seismic effect and in the second part, Analysis is
carried out on the same building designed seismically as per I.S 1893:2002. The
results have been compared for these two Analysis cases and Strengthening is
suggested for the affected members.
TABLE OF CONTENTS
CERTIFICATE i
ACKNOWLEDGEMENTS ii
ABSTRACT iii
TABLE OF CONTENTS iv
LIST OF FIGURES vi
LIST OF TABLES vii
Chapter 1 Introduction
1.1 General
1.2 Evaluation Criteria
1.3 Simplified Non-Linear Approach
1.4 Objective
Chapter 2 Literature Review 6-18
2.1 Introduction 6
2.2 Evaluation by elastic approach 6
2.3-2.7 Non-Linear Approach Research find outs 8
2.8 Direction for Present Research 18
Chapter 3 ATC-40 procedure for Seismic Evaluation 19-26
3.1 Procedure to determine Capacity 19
3.2 Conversion of Capacity Curve to Capacity Spectrum 21
3.3 Performance Point 23
Chapter 4 Analysis of Symmetrical Building 27-42
4.1 Description of Building 27
4.2 Loading Calculations 27
4.3 Normalized mode shape calculations 28
4.4 Description of ANSYS Model 30
4.4.1 Element Types 31
4.4.2 Element Constants 32
4.4.3 Material Properties 33
4.4.4 Modeling on ANSYS 33
4.4.5 Meshing 34
4.4.6 Boundary Conditions 35
4.4.7 Analysis Procedure and options 35
4.5 Capacity Curve 38
4.5.1 Conversion to Capacity Spectrum 38
4.6 Response Spectrum Plot 39
Performance Point 40
Observations 41
iv
Chapter 5 Analysis of L-shaped Building 43-67
Part 1 Analysis of building designed as per I.S 456:2000 43-56
5.1 Description of Building 43
5.2 Loading Calculations 44
5.2.1 Loading on Beams 44
5.2.2 Weight Calculations 46
5.2.3 Normalized mode shapes 46
5.3 Description of ANSYS Model 47
5.3.1 Element Types 47
5.3.2 Element Constants 47
5.3.3 Material Properties 48
5.3.4 Modeling on ANSYS 48
5.3.5 Meshing 49
5.3.6 Boundary Conditions 50
5.3.7 Analysis Procedure and options 50
5.4 Capacity Curve 52
5.4.1 Capacity Spectrum 53
5.5 Response Spectrum 53
5.6 Observations 54,56
Part 2 Analysis of building designed as per I.S 1893:2002 57-67
5.8 Description of ANSYS Model 57
5.8.1 Element Constants 58
5.8.2 Meshing 60
5.8.3 Boundary Conditions 61
5.8.4 Analysis procedure and options 61
5.9 Capacity Curve Plot 62
5.9.1 Capacity Spectrum 63
Performance point 63
5.11 Observations 64,66
5.12 Comparison 67
Chapter 6 Conclusion
Scope of Further Study
68
69
References 70-72