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Questions and Answers

What is acceleration in the context of seismic terminology?

The time rate of velocity change, commonly measured in 'g'.

What is an aftershock?

One of a series of smaller quakes following the main shock of the earthquake.

What does an accelerogram represent?

The record from an accelerograph showing acceleration as a function of time.

What is meant by the term 'brittle failure'?

Failure in material due to limited plastic range, occurring suddenly without warning. Signup and view all the answers

Define base isolation.

A method using flexible bearings to detach a building superstructure from its foundation. Signup and view all the answers

The _____ is the central part of the earth below a depth of 2,900 kilometers.

Core Signup and view all the answers

Which of the following describes 'ductility'?

Ability to absorb energy and deform without failing Signup and view all the answers

Match the following terms with their definitions:

Amplitude = Maximum deviation from mean of centerline of a wave Attenuation = Reduction of amplitude due to energy dissipation Deflection = Displacement of a member due to external force Drift = Horizontal displacement of basic building elements Signup and view all the answers

What is the definition of acceleration in the context of seismic terminology?

The time rate of velocity change, commonly measured in 'g'. Signup and view all the answers

What is a diaphragm in the context of earthquake engineering?

Generally a horizontal member, such as a floor or roof slab, which distributes lateral forces. Signup and view all the answers

What does an accelerogram show?

Acceleration as a function of time. Signup and view all the answers

What is a base isolation?

A method using flexible bearings to detach a building superstructure from its foundation. Signup and view all the answers

Brittle failure occurs in materials with limited plastic range, indicating that it can fail suddenly without warning signs.

True Signup and view all the answers

What is the term for the point in a building where it would be exactly balanced?

Center of mass. Signup and view all the answers

What is defined as the rate at which natural vibration decays as a result of energy absorption?

Damping Signup and view all the answers

What is the depth classification of shallow earthquakes?

0-70 kilometers. Signup and view all the answers

What is considered a critical damping?

The minimum damping that allows a displaced system to return to its initial position without oscillation Signup and view all the answers

What does the term deformation refer to in the context of earthquakes?

Permanent distortion due to seismic forces. Signup and view all the answers

Study Notes

Bohol Island State University (BISU)

Located in Tagbilaran City, Bohol, Philippines.
Vision: To be a premier Science and Technology university promoting sustainable development through quality education.
Mission: Committed to quality higher education in arts, sciences, professional, and technological fields, along with research and development.

Glossary of Seismic Terminology

Acceleration: Rate of velocity change measured in "g"; for Earth, approximately 32 ft/sec² or 980 cm/sec².
Accelerogram: Data record from an accelerograph, showing ground acceleration over time.
Accelerograph: Instrument that records strong motion earthquake ground acceleration.
Aftershock: Smaller quakes occurring after the main earthquake event.
Amplification: Increased acceleration and potential damage when ground motion frequency matches a building's natural period.
Amplitude: Maximum distance from the wave's mean centerline.
Attenuation: Decrease in wave amplitude due to energy loss over distance and time.
Axial Load: Force aligned with the primary axis of a structural member.
Base Isolation: Technique involving flexible bearings to detach a building from its foundation, reducing seismic forces.
Base Shear (Equivalent Lateral Force): Total shear force acting at the building's base.
Brittle Failure: Sudden material failure with no warning due to limited plastic deformation capacity.

Building Configuration Terms

Building Configuration: Overall size, shape, and proportions; arrangement of structural and nonstructural elements.
Regular Configuration: Buildings effectively resisting lateral forces using shear walls or moment-resistant frames, showing simple and symmetrical designs.
Irregular Configuration: Deviation from symmetry and simplicity in structural design.
Structural Configuration: Arrangement of components that carry vertical loads and resist lateral forces.

Earth Composition

Core: Earth's central part, composed of iron and nickel; outer layer is molten with a solid inner core.
Creep: Slow periodic movement along a fault without causing earthquakes.
Crust: The uppermost layer of the Earth, about 80 km thick, composed of crustal rocks and sediments, primarily silicon, aluminum, and iron.

Seismic Design Concepts

Damping: Energy absorption rate affecting the decay of natural vibrations in structures; design measures can optimize damping to reduce seismic forces.
Critical Damping: Minimum damping allowing a displaced system to return to its original position without oscillation.
Deflection: Movement of a structural member due to external forces.
Deformation: Permanent distortion caused by seismic activity.
Depth of Focus: The depth of an earthquake's focus, categorized as shallow (0-70 km), intermediate (70-300 km), or deep (300-700 km).
Design Earthquake: Typically defined as two-thirds of the maximum considered earthquake.
Diaphragm: Horizontal structural element (e.g., floor or roof slab) that distributes lateral forces to vertical supports.
Displacement: Lateral movement caused by applied forces.
Drift: Horizontal displacement of building elements due to lateral forces from earthquakes.
Ductility: Ability of a material to deform under stress without failing.

Bohol Island State University (BISU)

Located in Tagbilaran City, Bohol, Philippines.
Vision: To be a premier Science and Technology university promoting sustainable development through quality education.
Mission: Committed to quality higher education in arts, sciences, professional, and technological fields, along with research and development.

Glossary of Seismic Terminology

Acceleration: Rate of velocity change measured in "g"; for Earth, approximately 32 ft/sec² or 980 cm/sec².
Accelerogram: Data record from an accelerograph, showing ground acceleration over time.
Accelerograph: Instrument that records strong motion earthquake ground acceleration.
Aftershock: Smaller quakes occurring after the main earthquake event.
Amplification: Increased acceleration and potential damage when ground motion frequency matches a building's natural period.
Amplitude: Maximum distance from the wave's mean centerline.
Attenuation: Decrease in wave amplitude due to energy loss over distance and time.
Axial Load: Force aligned with the primary axis of a structural member.
Base Isolation: Technique involving flexible bearings to detach a building from its foundation, reducing seismic forces.
Base Shear (Equivalent Lateral Force): Total shear force acting at the building's base.
Brittle Failure: Sudden material failure with no warning due to limited plastic deformation capacity.

Building Configuration Terms

Building Configuration: Overall size, shape, and proportions; arrangement of structural and nonstructural elements.
Regular Configuration: Buildings effectively resisting lateral forces using shear walls or moment-resistant frames, showing simple and symmetrical designs.
Irregular Configuration: Deviation from symmetry and simplicity in structural design.
Structural Configuration: Arrangement of components that carry vertical loads and resist lateral forces.

Earth Composition

Core: Earth's central part, composed of iron and nickel; outer layer is molten with a solid inner core.
Creep: Slow periodic movement along a fault without causing earthquakes.
Crust: The uppermost layer of the Earth, about 80 km thick, composed of crustal rocks and sediments, primarily silicon, aluminum, and iron.

Seismic Design Concepts

Damping: Energy absorption rate affecting the decay of natural vibrations in structures; design measures can optimize damping to reduce seismic forces.
Critical Damping: Minimum damping allowing a displaced system to return to its original position without oscillation.
Deflection: Movement of a structural member due to external forces.
Deformation: Permanent distortion caused by seismic activity.
Depth of Focus: The depth of an earthquake's focus, categorized as shallow (0-70 km), intermediate (70-300 km), or deep (300-700 km).
Design Earthquake: Typically defined as two-thirds of the maximum considered earthquake.
Diaphragm: Horizontal structural element (e.g., floor or roof slab) that distributes lateral forces to vertical supports.
Displacement: Lateral movement caused by applied forces.
Drift: Horizontal displacement of building elements due to lateral forces from earthquakes.
Ductility: Ability of a material to deform under stress without failing.