Title Seismic Design Concepts and Calculations 1.6 MB 130
```                            UNIT I
Magnitude:
Measure of the amount of energy released during an earthquake. It is usually expressed using Richter scale.
UNIT II
EARTHQUAKE HISTORY
Fig 1
Solution
MDH=MDC=29.9 kN-m
MIE=119.2 Kn-m
Corner joints
Detailing for Ductility
A.  Girders
Solution
Bending of column about weak axis
EARTHQUAKE RESPONSE OF STRUCTURES
INTRODUCTION
BASED ON ELASTIC PROPERTY OF STRUCTURAL
ACCELERATION RESPONSE SPECTRUM
VELOCITY RESPONSE SPECTRUM
DISPLACEMENT RESPONSE SPECTRUM
INELASTIC RESPONSE SPECTRUM
SDOF SYSTEM
SEISMOGRAPHIC INSTRUMENTS
VIBROMETER
Φ =
GENERAL
RESISTANCE OFFERED BY VARIOUS STRUCTURAL ELEMENTS
METALS
CONCRETE
REINFORCED CONCRETE
PRESTRESSED CONCRETE
BRICK AND MASONRY
WOOD
DUCTILITY & ENERGY ABSORPTION
Design objectives
Anatomy of building
Overall form
Web reinforcement shall consist of vertical hoops. A vertical hoop is a closed stirrup having a 135 hoop with a 10-diameter extension (but not < 75 mm) at each end that is embedded in the confined core. The min diameter of the bar forming a hoop shall be 6 mm. However, in beams with a clear span exceeding 5 m, the minimum bar diameter shall be 8-mm.

Columns
Spiral or circular hoops or rectangular hoops
Beam column joints
Damage studies have shown that considerable distress may be suffered in this area, the principal failure mechanism being
Shear within joint
Anchorage failure of beam bars anchored in the joint
Bond failure
It should be emphasized that these effects exists under non-seismic loading but are of much insignificance under seismic conditions and the effects are much aggravated by cyclic loading. Design practice is based on the fundamental concept that failure should not occur within the joint, so that it should be strong enough to withstand the yielding of connecting beams (usually) or columns.
Anchoring
Shear walls
DISCUSSION ON THE CODAL PROVISIONS GIVEN IN IS1893-2002 AND IS4326-1993
6.3.5 INCREASE IN PERMISSIBLE STRESSES
6.3.5.2 Allowable pressure in soils is given in table 1 of IS code 1893
IS4326 – 1993 – E.Q. Resistant design and construction of building
TYPES OF CONSTRUCTIONS