BASICS OF DYNAMICS AND ASEISMIC DESIGN

BASICS OF DYNAMICS AND ASEISMIC DESIGN                                                         L T P C

3   0   0 3

OBJECTIVE

   The main objective of  this course is to introduce to the student the phenomena of
      earthquakes,  the  process,  measurements  and  the  factors  that  affect  the  design  of
      structures in seismic areas. This objective is achieved through imparting rudiments of
      theory of vibrations necessary to understand and analyse the dynamic forces caused by
      earthquakes and structures. Further, the student is also taught the codal provisions as
      well as the aseismic design methodology.

UNIT I             THEORY OF VIBRATIONS                                                                                   9

Concept of inertia and damping - Types of Damping - Difference between static forces and dynamic excitation - Degrees of freedom - SDOF idealisation - Equations of motion of SDOF system for mass as well as base excitation - Free vibration of SDOF system - Response to harmonic excitation - Impulse and response to unit impulse - Duhamel integral

UNIT II            MULTIPLE DEGREE OF FREEDOM SYSTEM                                                   9

Two degree of freedom system  - Normal modes of vibration  - Natural frequencies  - Mode shapes - Introduction to MDOF systems - Decoupling of equations of motion - Concept of mode superposition (No derivations).

UNIT III           ELEMENTS OF SEISMOLOGY                                                                            9

Causes of Earthquake - Geological faults - Tectonic plate theory - Elastic rebound - Epicentre - Hypocentre - Primary, shear and Raleigh waves - Seismogram - Magnitude and intensity of earthquakes - Magnitude and Intensity scales - Spectral Acceleration - Information on some disastrous earthquakes

UNIT IV           RESPONSE OF STRUCTURES TO EARTHQUAKE                                         9

Response and design spectra  - Design earthquake  - concept of peak acceleration  - Site specific response spectrum - Effect of soil properties and damping  - Liquefaction of soils -
Importance of ductility - Methods of introducing ductility into RC structures.

UNIT V            DESIGN METHODOLOGY                                                                                    9

IS 1893, IS 13920 and IS 4326 - Codal provisions - Design as per the codes - Base isolation

techniques - Vibration control measures - Important points in mitigating effects of earthquake

on structures.

TOTAL: 45 PERIODS

TEXT BOOK

1.  Chopra,  A.K.,     “Dynamics  of  Structures     -  Theory  and  Applications  to  Earthquake

Engineering”, Second Edition, Pearson Education, 2003.

REFERENCES

1.  Biggs, J.M., “Introduction to Structural Dynamics”, McGraw-Hill Book Co., N.Y., 1964

2.  Dowrick, D.J., “Earthquake Resistant Design”, John Wiley & Sons, London, 1977

3.  Paz, M.,  “Structural Dynamics  - Theory & Computation”, CSB Publishers & Distributors,
      Shahdara, Delhi, 1985

4.  NPEEE Publication