What is site amplification factor?
The site amplification factor was usually considered as scalar values, such as amplification of peak ground acceleration or peak ground velocity, increments of seismic intensity in the conventional earthquake early warning system.
What is amplification in earthquake?
Shaking levels at a site may be increased, or amplified, by focusing of seismic energy caused by the geometry of the sediment velocity structure, such as basin subsurface topography, or by surface topography.
What is MCE in earthquake?
The MCE (Maximum Credible Earthquake) is the most severe earthquake effects considered by this standard. The DBE (Design Basic Earthquake) is the earthquake effects which can reasonably be expected to occur at least once during the design life of the structure.
Is amplification an earthquake hazard?
Factors controlling ground shaking requires detailed mapping of the soils and their properties, amplification characteristics are not included in the National Seismic Hazard Maps.
What is soil amplification?
In a simple word, amplification is the increase of amplitude due to surface soft soil.
What is soil site amplification?
Site amplification essential for seismic zonation is defined here as a peak value of spectrum ratio between ground surface and a base layer. The amplification was investigated using surface and base accelerations recorded in a number of KiK-net downhole arrays in Japan during three recent destructive earthquakes.
What is MCE & DBE?
MCE or the maximum considered earthquake is defined as the ground shaking level at the building site with a 2% probability of exceedance in 50 years, while DBE or the design basis earthquake is the level with a 10% probability of exceedance in 50 years and is assumed to be two-thirds of MCE.
What is OBE and SSE?
Enclosure 7 – Definitions: SSE (Safe Shutdown Earthquake) & OBE (Operating Basis Earthquake).
What is material amplification?
Material amplification: Intensity (amplitude of vertical movement) of ground shaking more severe in unconsolidated materials. – Seismic energy attenuated more and propagated less distance. in unconsolidated materials.
What ground factors can lead to ground amplification of seismic waves?
Site effects include the following five factors.
- The softness of the soil or rock beneath a site.
- The total thickness of soil to bedrock.
- Sedimentary basins (deep geologic structure).
- Ground failure potential (see Liquefaction and Landslides).
- Topography.
What type of fault is the San Andreas Fault?
strike-slip fault – a fault on which the two blocks slide past one another. The San Andreas Fault is an example of a right lateral fault.
What are some secondary hazards produced from ground shaking?
Secondary hazards are caused as a consequence of that ground shaking, such as ground settlement, lateral ground displacement, liquefaction, landslides and rock falls, tsunamis, floods, fires and falling debris.
What is design based earthquake?
design-basis earthquake (DBE): “That earthquake for which the safety systems are designed to remain functional both during and after the event, thus assuring the ability to shut down and maintain a safe configuration.”
How is material amplification related to earthquake damage?
Soft soil means bigger waves and stronger amplification. In short, the softer and thicker the soil, the greater the shaking or amplification of waves produced by an earthquake. As a result, building damage tends to be greater in areas of soft sediments or deep basins.
What types of materials amplify seismic waves?
Soft materials, such as unconsolidated sedimentary deposits like bay muds and even sedimentary rocks, amplify the shaking. Consequently, locations situated over sedimentary basins or on unconsolidated sedimentary deposits can be especially susceptible to strong shaking.
Which of the following sites is most likely to amplify ground motion?
Deep sedimentary basins can have a large effect on ground motion above them.
What is meant by seismic amplification?
amplification Shaking levels at a site may be increased, or amplified, by focusing of seismic energy caused by the geometry of the sediment velocity structure, such as basin subsurface topography, or by surface topography.
What are seismic site effects?
Seismic site effects are related to the amplification of seismic waves in superficial geological layers. The surface ground motion may be strongly amplified if the geological conditions are unfavorable (e.g. sediments).
How does layering affect the amplification of seismic motion?
This phenomenon may significantly strengthen the amplification of the seismic motion. The aggravation of the amplification level when compared to the case of horizontal layering may be up to a factor of 5 or 10. It depends on the velocity contrast between the layers and the geometry of the basin.
What are the factors that affect the amplification factor of soil?
The amplification happen because of: surface effect, focusing effect, Rocking effect, Scattering & passing effect. Based on the multiple reflection theory [1,2], the amplification factor is mostly controlled by S-wave velocity profile of soil (S-wave velocity and thickness).