EARTHQUAKE HAZARDS RELATED TO GEOTECHNICAL ENGINEERING

•         Ground Shaking: Shakes structures constructed on ground causing them to collapse

•         Liquefaction: Conversion of formally stable cohesionless soils to a fluid mass, causing damage to the structures

•         Landslides: Triggered by the vibrations

•         Retaining structure failure: Damage of anchored wall, sheet pile, other retaining walls and sea walls

•         Fire: [...]

Lateral Deformation and Spreading

Lateral Spreading: Liquefaction related phenomenon

Upslope portion of lateral spread at Budharmora, Gujarat

Lateral spreading in the soil beneath embankment causes the embankment to be pulled apart, producing the large crack down the center of the road.

Cracked Highway, Alaska, 1964

Lateral Deformation and Spreading

Ø  Down slope movement of soil, when loose sandy [...]

Earthquake Destruction: Fire

Earthquakes sometimes cause fire due to broken gas lines, contributing to the loss of life and economy.

The destruction of lifelines and utilities make impossible for firefighters to reach fires started and make the situation worse

eg.    1989 Loma Prieta

        1906 San Francisco

Earthquake Destruction: Tsunamis

Tsunamis can be generated when the sea floor [...]

Ground Improvement for Liquefaction Hazard Mitigation

Ground Improvement in IS Code

        “In poor and weak subsoils, the design of conventional shallow foundation for structures and equipment may present problems with respect to both sizing of foundations as well as control of foundation settlements. Traditionally, pile foundations have been employed often at enormous costs. A more [...]

A tuned mass damper, also known as an active mass damper (AMD) or harmonic absorber, is a device mounted in structures to prevent discomfort, damage, or outright structural failure caused by vibration. They are frequently used in power transmission, automobiles, and buildings.
How Tuned Mass Dampers Work

A tuned mass damper (TMD) consists [...]

MULTISTOREY REINFORCED CONCRETE BUILDINGS
A large number of reinforced concrete multistoreyed frame buildings were heavily damaged and many of them collapsed completely in Bhuj earthquake of 2001 in the towns of Kachchh District (viz., Bhuj, Bhachao, Anjar, Gandhidham and Rapar) and other district towns including Surat and Ahmedabad. In Ahmedabad alone situated at more than 250 [...]

Base Isolation Method
Conventional Construction Practice assumes Fixed Base Structures

The Dynamic Characteristics of Fixed Base Structures are determined by the general characteristics of the structural system
The Designer can only slightly adjust those Dynamic Characteristics
As a matter of fact, most common Building Structures have unfavorable Dynamic Characteristics that result in increased [...]

The following types of damage are quite common in reinforced concrete buildings:

Sliding of roofs off the supports

Where the beams simply rest on walls or columns, they are bound to slide, when the earthquake intensity exceeds the frictional resistance and many times leave the support and fall down, particularly if the bearing length is small.

Falling [...]

Reinforced concrete multi-storied buildings are very complex to model as structural systems for analysis. Usually, they are modeled as two-dimensional or three-dimensional frame systems using finite beam elements. For evaluating stiffness matrix of beam elements, the properties required are – area of section, effective area in shear, and moment of inertia about the axis of [...]

Structural dynamics is a subset of structural analysis which covers the behaviour of structures subjected to dynamic loading. Dynamic loads include people, wind, waves, traffic, earthquakes, and blasts. Any structure can be subject to dynamic loading. Dynamic analysis can be used to find dynamic displacements, time history, and modal analysis.
A static load is one which [...]

What is an Earthquake and How does it has effect on Civil Engineering Structures?
WHAT IS AN EARTHQUAKE?
An earthquake is a sudden, rapid shaking of the Earth caused by the breaking and shifting of rock beneath the Earth’s surface. For hundreds of millions of years, the forces of plate tectonics have shaped the Earth as the [...]

Dynamics of Structures: Theory and Applications to Earthquake Engineering
Earthquake Dynamics of Structures, a Primer
Seismic Behavior and Design of Steel Shear Walls
Seismic Design Manual