What is probabilistic seismic hazard analysis?
Probabilistic Seismic Hazard Analysis (PSHA) is a method used to estimate the level of ground motion with a specified probability of exceedance (Cornell, 1968; Reiter, 1990).
What is MCE and DBE?
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.
What is MCE ground motion?
MCEs. In a normal seismic hazard analyses intended for the public, that of a “maximum considered earthquake”, or “maximum considered event” (MCE) for a specific area, is an earthquake that is expected to occur once in approximately 2,500 years; that is, it has a 2-percent probability of being exceeded in 50 years.
What are the types of seismic hazard?
Earthquake Hazards
- Ground Shaking. If an earthquake generates a large enough shaking intensity, structures like buildings, bridges and dams can be severley damaged, and cliffs and sloping ground destabilised.
- Tsunami.
- Landslides and Rockfalls.
- Subsidence and Lateral Spreading.
- Liquefaction.
What is seismic hazard curve?
A hazard curve, as calculated on the CD, is a plot of the annual frequency of exceedance (FEX) versus peak ground acceleration or one of the spectral accelerations.
Why is probabilistic seismic hazard analysis Psha still used?
Probabilistic Seismic Hazard Analysis (PSHA) has been widely used for 50 years. PSHA rests on assumptions now known to conflict with earthquake physics. Many damaging earthquakes occur in regions rated low-risk by PSHA hazard maps. Seismologists and engineers should clearly acknowledge PSHA’s shortcomings.
What is a liquefaction zone?
In liquefaction zones, saturated sand and silt take on the characteristics of a liquid during the intense shaking of an earthquake, according to the U.S. Geological Survey. During violent quakes, seemingly solid ground can turn into the consistency of cake batter, collapsing overhead buildings and infrastructure.
What is earthquake motion?
Ground motion is the movement of the earth’s surface from earthquakes or explosions. Ground motion is produced by waves that are generated by sudden slip on a fault or sudden pressure at the explosive source and travel through the earth and along its surface. A recording of ground motion.
How are seismic hazards caused?
Ground shaking is the primary cause of earthquake damage to man-made structures. Many factors influence the strength of earthquake shaking at a site including the earthquake’s magnitude, the site’s proximity to the fault, the local geology, and the soil type.
What is a seismic hazard zone?
A seismic hazard zone describes an area with a particular level of hazard due to earthquakes. Typically, a high seismic hazard zone is nearest a seismic zone where there are more earthquakes, and a lower seismic hazard zone is farther away from a seismic zone.