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Seismic Microzonation
Seismic microzonation is defined as the process of subdividing a potential seismic or earthquake prone area into zones with respect to some geological and geophysical characteristics of the sites such as ground shaking, liquefaction susceptibility, landslide and rock fall hazard, earthquake-related flooding, so that seismic hazards at different locations within the area can correctly be identified. Microzonation provides the basis for site-specific risk analysis, which can assist in the mitigation of earthquake damage. In most general terms, seismic microzonation is the process of estimating the response of soil layers under earthquake excitations and thus the variation of earthquake characteristics on the ground surface. Regional geology can have a large effect on the characteristics of ground motion.Seed, H. B. and Schnabel, P. B., 1972. Soil and Geological Effects on Site Response During Earthquakes. Proc. of First International Conf. on Microzonation for Safer Construction – ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bangkok Microzonation Map
Bangkok, officially known in Thai as Krung Thep Maha Nakhon and colloquially as Krung Thep, is the capital and most populous city of Thailand. The city occupies in the Chao Phraya River delta in central Thailand and has an estimated population of 10.539 million as of 2020, 15.3 percent of the country's population. Over 14 million people (22.2 percent) lived within the surrounding Bangkok Metropolitan Region at the 2010 census, making Bangkok an extreme primate city, dwarfing Thailand's other urban centres in both size and importance to the national economy. Bangkok traces its roots to a small trading post during the Ayutthaya Kingdom in the 15th century, which eventually grew and became the site of two capital cities, Thonburi in 1768 and Rattanakosin in 1782. Bangkok was at the heart of the modernization of Siam, later renamed Thailand, during the late-19th century, as the country faced pressures from the West. The city was at the centre of Thailand's political struggles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long Period Ground Motion
Long period ground motion is ground movement during an earthquake with a period longer than 1 second. The frequency of such waves is 1 Hz or lower, placing them in the infrasonic part of the audio spectrum. See also *Love wave *S-wave *P-wave *Rayleigh wave *Transverse wave *Seismic microzonation Seismic microzonation is defined as the process of subdividing a potential seismic or earthquake prone area into zones with respect to some geological and geophysical characteristics of the sites such as ground shaking, liquefaction susceptibilit ... References Seismology {{Seismology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtremor
Microtremor is a low amplitude (in the order of micrometres) ambient vibration of the ground caused by man-made or atmospheric disturbances. The term Ambient Vibrations is now preferred to talk about this phenomenon. Observation of microtremors can give useful information on dynamic properties of the site such as predominant period and amplitude. Microtremor observations are easy to perform, inexpensive and can be applied to places with low seismicity as well, hence, microtremor measurements can be used conveniently for seismic microzonation.Nakamura, Y., 1989. A Method for Dynamic Characteristics Estimation of Subsurface Using Microtremor on the Ground Surface. Quarterly Report of RTRI, vol. 30, No. 1, pp. 25–33. More detailed information on the shear wave velocity profile of the site can be obtained from microtremor array observation. History After the pioneering work by Kannai and Tanaka,Tokimatsu, K., 1997. Geotechnical Site Characterization Using Surface Wave. Proc., 1s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ambient Vibrations
In geophysics, geology, civil engineering, and related disciplines, seismic noise is a generic name for a relatively persistent vibration of the ground, due to a multitude of causes, that is often a non-interpretable or unwanted component of signals recorded by seismometers. Physically, seismic noise arises primarily due to surface or near surface sources and thus consists mostly of elastic surface waves. Low frequency waves (below 1 Hz) are commonly called microseisms and high frequency waves (above 1 Hz) are called microtremors. Primary sources of seismic waves include human activities (such as transportation or industrial activities), winds and other atmospheric phenomena, rivers, and ocean waves. Seismic noise is relevant to any discipline that depends on seismology, including geology, oil exploration, hydrology, and earthquake engineering, and structural health monitoring. It is often called the ambient wavefield or ambient vibrations in those disciplines (however, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear Wave Velocity
Shear may refer to: Textile production *Animal shearing, the collection of wool from various species **Sheep shearing *The removal of nap during wool cloth production Science and technology Engineering *Shear strength (soil), the shear strength of soil under loading *Shear line (locksmithing), where the inner cylinder ends and the outer cylinder begins in a cylinder lock *Shearing (manufacturing), a metalworking process which cuts stock without the formation of chips or the use of burning or melting *Shear (sheet metal), various tools to shear sheet metal *Board shear, in bookbinding, a tool to cut board or paper *Shear pin, in machinery, such as a plough, designed to shear (break) when a certain force is exceeded, to protect other components of the machine. *Shearing interferometer, in optics, a simple and very common means to check the collimation of beams by observing interference *Shearing in computer graphics, more commonly called screen tearing *Shear wall, a wall composed o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Penetration Test
The standard penetration test (SPT) is an in-situ dynamic penetration test designed to provide information on the geotechnical engineering properties of soil. This test is the most frequently used subsurface exploration drilling test performed worldwide. The test procedure is described in ISO 22476-3, ASTM D1586 and Australian Standards AS 1289.6.3.1. The test provides samples for identification purposes and provides a measure of penetration resistance which can be used for geotechnical design purposes. Many local and widely published international correlations which relate blow count, or N-value, to the engineering properties of soils are available for geotechnical engineering purposes. Procedure The test uses a thick-walled sampling tube, with an outside diameter of 5.08 cm and an inside diameter of 3.5 cm, and a length of around 65 cm. The sampling tube is driven into the ground at the bottom of a borehole by blows from a slide hammer with a mass of 63.5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear Wave Velocity
Shear may refer to: Textile production *Animal shearing, the collection of wool from various species **Sheep shearing *The removal of nap during wool cloth production Science and technology Engineering *Shear strength (soil), the shear strength of soil under loading *Shear line (locksmithing), where the inner cylinder ends and the outer cylinder begins in a cylinder lock *Shearing (manufacturing), a metalworking process which cuts stock without the formation of chips or the use of burning or melting *Shear (sheet metal), various tools to shear sheet metal *Board shear, in bookbinding, a tool to cut board or paper *Shear pin, in machinery, such as a plough, designed to shear (break) when a certain force is exceeded, to protect other components of the machine. *Shearing interferometer, in optics, a simple and very common means to check the collimation of beams by observing interference *Shearing in computer graphics, more commonly called screen tearing *Shear wall, a wall composed o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predominant Period
In music theory, a predominant chord (also pre-dominant) is any chord which normally resolves to a dominant chord.Benward & Saker (2009). ''Music in Theory and Practice: Volume II'', Glossary, p.359. Eighth Edition. . "Any chord in functional harmony that normally resolves to the dominant chord." Examples of predominant chords are the subdominant (IV, iv), supertonic (ii, ii°), Neapolitan sixth and German sixth. Other examples are the secondary dominant (V/V) and secondary leading tone chord. Predominant chords may lead to secondary dominants. Predominant chords both expand away from the tonic ''and'' lead to the dominant, affirming the dominant's pull to the tonic.Cleland, Kent D. and Dobrea-Grindahl, Mary (2013). ''Developing Musicianship Through Aural Skills: A Holistic Approach to Sight Singing and Ear Training'', p.255. Routledge. . Thus they lack the stability of the tonic and the drive towards resolution of the dominant. The predominant harmonic function is part of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Francisco Bay
San Francisco Bay is a large tidal estuary in the U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the big cities of San Francisco, San Jose, and Oakland. San Francisco Bay drains water from approximately 40 percent of California. Water from the Sacramento and San Joaquin rivers, and from the Sierra Nevada mountains, flow into Suisun Bay, which then travels through the Carquinez Strait to meet with the Napa River at the entrance to San Pablo Bay, which connects at its south end to San Francisco Bay. It then connects to the Pacific Ocean via the Golden Gate strait. However, this entire group of interconnected bays is often called the ''San Francisco Bay''. The bay was designated a Ramsar Wetland of International Importance on February 2, 2017. Size The bay covers somewhere between , depending on which sub-bays (such as San Pablo Bay), estuaries, wetlands, and so on are included in the measurement. The main part of the bay meas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loma Prieta Earthquake
The 1989 Loma Prieta earthquake occurred on California's Central Coast on October 17 at local time. The shock was centered in The Forest of Nisene Marks State Park in Santa Cruz County, approximately northeast of Santa Cruz on a section of the San Andreas Fault System and was named for the nearby Loma Prieta Peak in the Santa Cruz Mountains. With an magnitude of 6.9 and a maximum Modified Mercalli intensity of IX (''Violent''), the shock was responsible for 63 deaths and 3,757 injuries. The Loma Prieta segment of the San Andreas Fault System had been relatively inactive since the 1906 San Francisco earthquake (to the degree that it was designated a seismic gap) until two moderate foreshocks occurred in June 1988 and again in August 1989. Damage was heavy in Santa Cruz County and less so to the south in Monterey County, but effects extended well to the north into the San Francisco Bay Area, both on the San Francisco Peninsula and across the bay in Oakland. No surface faulting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cypress Structure
The Cypress Street Viaduct, often referred to as the Cypress Structure or the Cypress Freeway, was a 1.6-mile-long (2.5 km), raised two-deck, multi-lane (four lanes per tier) freeway constructed of reinforced concrete that was originally part of the Nimitz Freeway ( State Route 17, and later, Interstate 880) in Oakland, California. It replaced an earlier single-deck viaduct constructed in the 1930s as one of the approaches to the San Francisco–Oakland Bay Bridge. It was located along Cypress Street between 7th Street and Interstate 80 in the West Oakland neighborhood. It officially opened to traffic on June 11, 1957, and was in use until October 17, 1989. At approximately 5:04 p.m. that day, a magnitude 6.9 earthquake struck the Bay Area, resulting in a large portion of the freeway's upper deck collapsing onto the lower deck. The collapse killed 42 people and resulted in the subsequent demolition of the structure. The Cypress Freeway Memorial Park is located in Oaklan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EERI
The Earthquake Engineering Research Institute (EERI) is a leading technical society in dissemination of earthquake risk and earthquake engineering research both in the U.S. and globally. EERI members include researchers, geologists, geotechnical engineers, educators, government officials, and building code regulators. Their mission, as stated in their 5-year plan published in 2006, has three points: "Advancing the science and practice of earthquake engineering; Improving understanding of the impact of earthquakes on the physical, social, economic, political, and cultural environment; and Advocating comprehensive and realistic measures for reducing the harmful effects of earthquakes". Goals In the 2006 5-year plan, the EERI has identified four main goals towards fulfilling their mission and planned strategies to carry them out. #"Enhance and expand educational materials and technical programs." They will hold two seminars per year on topics intended to interest a wide audience. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Bangkok Microzonation Map")
