List of international earthquake acceleration coefficients. A list of earthquake coefficients used in structural design for earthquake engineering [1] around the world. For example, a coefficient of 0.09 indicates that a building is designed that 0.09457 of its weight can be applied horizontally during an earthquake.[ clarification needed ]
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From Australian Standard 1170.4. Coeffiecients are based on 10% chance exceedence in 50 years.
Note: Meckering, Western Australia, has the largest coefficient in Australia of 0.22.
From ΕAΚ 2003 building code
An earthquake – also called a quake, tremor, or temblor – is the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume.
The Modified Mercalli intensity scale measures the effects of an earthquake at a given location. This is in contrast with the seismic magnitude usually reported for an earthquake.
A seismic hazard is the probability that an earthquake will occur in a given geographic area, within a given window of time, and with ground motion intensity exceeding a given threshold. With a hazard thus estimated, risk can be assessed and included in such areas as building codes for standard buildings, designing larger buildings and infrastructure projects, land use planning and determining insurance rates. The seismic hazard studies also may generate two standard measures of anticipated ground motion, both confusingly abbreviated MCE; the simpler probabilistic Maximum Considered Earthquake, used in standard building codes, and the more detailed and deterministic Maximum Credible Earthquake incorporated in the design of larger buildings and civil infrastructure like dams or bridges. It is important to clarify which MCE is being discussed.
The 1964 Alaskan earthquake, also known as the Great Alaskan earthquake and Good Friday earthquake, occurred at 5:36 pm AKST on Good Friday, March 27. Across south-central Alaska, ground fissures, collapsing structures, and tsunamis resulting from the earthquake caused about 131 deaths.
Peak ground acceleration (PGA) is equal to the maximum ground acceleration that occurred during earthquake shaking at a location. PGA is equal to the amplitude of the largest absolute acceleration recorded on an accelerogram at a site during a particular earthquake. Earthquake shaking generally occurs in all three directions. Therefore, PGA is often split into the horizontal and vertical components. Horizontal PGAs are generally larger than those in the vertical direction but this is not always true, especially close to large earthquakes. PGA is an important parameter for earthquake engineering, The design basis earthquake ground motion (DBEGM) is often defined in terms of PGA.
Gravimetry is the measurement of the strength of a gravitational field. Gravimetry may be used when either the magnitude of a gravitational field or the properties of matter responsible for its creation are of interest. The study of gravity changes belongs to geodynamics.
A response spectrum is a plot of the peak or steady-state response of a series of oscillators of varying natural frequency, that are forced into motion by the same base vibration or shock. The resulting plot can then be used to pick off the response of any linear system, given its natural frequency of oscillation. One such use is in assessing the peak response of buildings to earthquakes. The science of strong ground motion may use some values from the ground response spectrum for correlation with seismic damage.
Earthquake engineering is an interdisciplinary branch of engineering that designs and analyzes structures, such as buildings and bridges, with earthquakes in mind. Its overall goal is to make such structures more resistant to earthquakes. An earthquake engineer aims to construct structures that will not be damaged in minor shaking and will avoid serious damage or collapse in a major earthquake. A properly engineered structure does not necessarily have to be extremely strong or expensive. It has to be properly designed to withstand the seismic effects while sustaining an acceptable level of damage.
The Indian subcontinent has a history of devastating earthquakes. The major reason for the high frequency and intensity of the earthquakes is that the Indian plate is driving into Asia at a rate of approximately 47 mm/year. Geographical statistics of India show that almost 58% of the land is vulnerable to earthquakes. A World Bank and United Nations report shows estimates that around 200 million city dwellers in India will be exposed to storms and earthquakes by 2050. The latest version of seismic zoning map of India given in the earthquake resistant design code of India [IS 1893 2002] assigns four levels of seismicity for India in terms of zone factors. In other words, the earthquake zoning map of India divides India into 4 seismic zones unlike its previous version, which consisted of five or six zones for the country. According to the present zoning map, Zone 5 expects the highest level of seismicity whereas Zone 2 is associated with the lowest level of seismicity.
The 2006 Yogyakarta earthquake occurred at 05:53 local time on 27 May with a moment magnitude of 6.4 and a maximum MSK intensity of VIII (Damaging). Several factors led to a disproportionate amount of damage and number of casualties for the size of the shock, with more than 5,700 dead, tens of thousands injured, and financial losses of Rp 29.1 trillion. With limited effects to public infrastructure and lifelines, housing and private businesses bore the majority of damage, and the United States' National Geophysical Data Center classified the total damage from the event as extreme.
The lateral earth pressure is the pressure that soil exerts in the horizontal direction. It is important because it affects the consolidation behavior and strength of the soil and because it is considered in the design of geotechnical engineering structures such as retaining walls, basements, tunnels, deep foundations and braced excavations.
The 1999 Athens earthquake occurred on September 7 at 14:56:51 local time near Mount Parnitha in Greece with a moment magnitude of 6.0 and a maximum Mercalli intensity of IX (Violent). The proximity to the Athens metropolitan area resulted in widespread structural damage, mainly to the nearby suburban towns of Ano Liosia, Acharnes, Fyli, Thrakomakedones, Kifissia, Metamorfosi, Kamatero and Nea Filadelfeia. More than 100 buildings across those areas collapsed trapping scores of victims under their rubble while dozens more were severely damaged. With damage estimated at $3–4.2 billion, 143 people were killed, and up to 1,600 were treated for injuries in Greece's deadliest natural disaster in almost half a century.
Seismic base isolation, also known as base isolation, or base isolation system, is one of the most popular means of protecting a structure against earthquake forces. It is a collection of structural elements which should substantially decouple a superstructure from its substructure that is in turn resting on the shaking ground, thus protecting a building or non-building structure's integrity.
The 2008 Peloponnese earthquake killed two people, injured more than 220 and left at least 2,000 people homeless in north western Peloponnese, Greece, on June 8. The earthquake hit the area at 1525 EET, with a moment magnitude of 6.5, according to the Athens Geodynamic Institute. It was strongly felt as far away as in Athens and in parts of southern Italy. The US Geological Survey reported that the quake had a magnitude of 6.4. The epicenter of the tremor was located about 15 miles (32 km) southwest of the Greek port city of Patras, at a depth of 16 km. Interior Minister Prokopis Pavlopoulos dispatched rescue and recovery teams, the Red Cross and units of the army in order to assess the damage and the needs of survivors in the earthquake affected areas.
The 1952 Severo-Kurilsk earthquake struck off the coast of the Kamchatka Peninsula. The 9.0 Mw earthquake triggered a major tsunami that hit Severo-Kurilsk, Kuril Islands, Sakhalin Oblast, Russian SFSR, USSR, on 5 November 1952 at 04:58 local time. This led to the destruction of many settlements in Sakhalin Oblast and Kamchatka Oblast, while the main impact struck the town of Severo-Kurilsk. It was the most powerful earthquake ever recorded in Russia, and the fifth most powerful earthquake ever recorded in the world since modern seismography began in 1900.
The 1978 Thessaloniki earthquake occurred on 20 June at 23:03 local time. The shock registered 6.5 on the moment magnitude scale, had a maximum Mercalli intensity of VIII (Severe), and was felt throughout northern Greece, Yugoslavia and Bulgaria. It was the largest event in the area since the 1932 Ierissos earthquake.
Seismic codes or earthquake codes are building codes designed to protect property and life in buildings in case of earthquakes. The need for such codes is reflected in the saying, "Earthquakes don't kill people—buildings do." Or in expanded version, “Earthquakes do not injure or kill people. Poorly built manmade structures injure and kill people.”
Seismic intensity scales categorize the intensity or severity of ground shaking (quaking) at a given location, such as resulting from an earthquake. They are distinguished from seismic magnitude scales, which measure the magnitude or overall strength of an earthquake, which may, or perhaps may not, cause perceptible shaking.
The 2015 Lefkada earthquake occurred on November 17, 2015, 10:40:07 (EEST) with a moment magnitude of 6.5 located 19 km Southwest of the Greek island of Lefkada along with a depth of 11 km and intensities reaching as high as VIII (Severe) on the Modified Mercalli Scale. Two people lost their lives in the event and 4–8 others were hospitalized with injuries.
A moment magnitude 6.0 earthquake struck the island of Crete in Greece at a depth of 6 km on 27 September 2021. The epicenter of the earthquake was located southeast of Heraklion. The quake killed one person, injured 36 and damaged over 5,000 old buildings on the island.