THEORY EXAMINATION (SEM–VIII) 2016-17 EARTHQUAKE RESISTANT DESIGN

SECTION – A

Explain the following (Short Answer Type)

Seismic waves are the waves of energy generated during an earthquake that travel through the earth. The main types include P-waves, S-waves, and surface waves.

The epicenter is the point on the earth’s surface located directly above the earthquake focus where the earthquake originates.

Dynamic degrees of freedom represent the number of independent ways a structure can move during vibration, such as horizontal or vertical displacement.

Governing equations of vibrating systems can be developed using Newton’s method, energy method, and Lagrange’s equation approach.

To simplify structural modeling, assumptions such as linear elasticity, small deformations, and uniform material properties are used.

The time history method analyzes structural response by studying how a structure reacts to earthquake forces over time.

A response spectrum is a graph showing maximum structural response at different vibration frequencies during an earthquake.

Typical damage in masonry buildings includes cracks in walls and collapse of unsupported sections during earthquakes.

Indian codes prescribe web reinforcement to improve shear strength and ductility in structural members.

Machine foundations support heavy machines and reduce vibration effects. Common types include block and frame foundations.

Questions (Section A)

What are seismic waves?

Define epicenter.

What is dynamic degree of freedom?

What is response spectrum?

List types of machine foundation.

SECTION – B

Attempt any five (Long Answer Type)

The theory of elastic rebound explains earthquakes as the sudden release of stored energy when stressed rocks break along faults.

Faults and dips are geological features where rock layers shift, leading to earthquake formation.

An SDOF system represents a structure with one degree of freedom and is used to study vibration response under external forces.

Building response during earthquakes depends on factors such as structural stiffness, building height, material properties, and soil conditions.

Holzer’s numerical technique helps determine natural vibration periods of multi-degree-of-freedom systems.

Proper reinforcement arrangement in beam-column joints improves structural strength and earthquake resistance.

Response spectrum analysis helps engineers design structures capable of resisting earthquake forces.

IS code recommendations focus on ductility, reinforcement detailing, and structural safety during earthquakes.

Questions (Section B)

Explain the theory of elastic rebound.

What are faults and dips?

What factors affect building response during earthquakes?

What is response spectrum analysis?

Explain reinforcement detailing for earthquake resistance.

SECTION – C

Attempt any two (Detailed Explanation)

Earthquakes occur due to tectonic plate movements, volcanic activity, and sudden release of stress in the earth’s crust.

The equation of motion for a single-degree-of-freedom damped system describes displacement behavior over time during vibration.

Typical damages in reinforced concrete buildings include beam cracking, column failure, and foundation settlement.

Capacity design principles ensure structural safety by controlling where failure occurs during earthquakes.

Natural frequencies and mode shapes describe how multi-story structures vibrate during seismic activity.

Questions (Section C)

What are the causes of earthquakes?

Explain the equation of motion for damped systems.

What is capacity design principle?