Procedures for estimating earthquake ground motions. However, there are many examples of the use of pgv in engineering seismology and earthquake engineering, including as a parameter from which to estimate. Three different artificial neural network ann methods, namely, feedforward backpropagation ffbp, radial basis function rbf, and generalized regression neural networks grnns were applied to predict peak ground acceleration pga. Fannie mae peak ground acceleration the 2014 update of the fannie mae multifamily selling and servicing guide for property needs assessments pna has been revised to include a determination of site seismic hazard using the 475year 10% in 50year peak ground acceleration. Global earthquake hazard distribution peak ground acceleration. The varying pga results from an earthquake can be displayed on a shake map. I considered that ambiguous and not true in every situation, so i made a slightly less ambiguous statement in the comments.
Jul 26, 2017 an extension of the data collection to response spectral acceleration or peak ground velocity was considered. Typically only change this at interchange ramps, to prevent offramp vehicles from turning. May 05, 2017 a couple weeks ago on youtube john cadogan made the statement peak acceleration occurs at peak horsepower, referring to typical ic engines. By june 2003 this network recorded 60 triaxial accelerograms of seismic events. Pdf peak ground acceleration, velocity and displacement from. Mar 04, 2011 global earthquake hazard distribution peak ground acceleration is a 2. How can i calculate the peak ground acceleration from a.
Sample acceleration and velocity seismograms for small earthquakes a the eastwest component of a m l 3. Usgs fema earthquake intensity and classification are commonly measured. A couple weeks ago on youtube john cadogan made the statement peak acceleration occurs at peak horsepower, referring to typical ic engines. Distribution of peak ground acceleration, pga, values derived from the strong motion records used in the present work as a function of, a epicentral distance, r and, b moment magnitude, m. World bank, the wb the data set comes from both the global seismic hazard program and a database of earthquake events greater than 4. Learn more about accelerogram, seismic, seismology, geophysics, pga. The estimation of peak groundmotion parameters from spectral. The desired final contours were selected and polygon topology was ascertained as well as appropriate feature attributes.
Relationship between peak ground acceleration, peak ground. Prediction of peak ground acceleration of irans tectonic regions. Strong motion simulation for the philippines based on seismic. Spectral acceleration, with a value related to the natural frequency of vibration of the building, is used in earthquake engineering and gives a closer approximation to the motion of a building or other structure in an earthquake than the peak ground acceleration value, although there is normally a correlation between short period sa and pga. Spectral acceleration, sa, is the most commonly used intensity measure in practice today for analysis of buildings. Seiche the sloshing of a closed body of water from earthquake shaking. Consequently gmpes are more poorly constrained for large earthquakes than for small events.
This value represents the maximum acceleration that a ground motion will cause in a linear oscillator with a speci. The characteristics of strong ground motion, the site category, depth of the soil column, type of rock strata, and the dynamic soil properties at a particular site significantly influence the free field motion during an. In this article peak ground accelerations pgas observed in 38 earthquakes. Scaling of peak ground acceleration and peak ground velocity boll. Spectral acceleration sa is a unit measured in g the acceleration due to earths gravity, equivalent to gforce that describes the maximum acceleration in an earthquake on an object specifically a damped, harmonic oscillator moving in one physical dimension. Estimation of peak ground acceleration from horizontal rigid body displacement. Peak ground acceleration pga the peak ground acceleration during an earthquake measured in units of g gravity. This is primarily because in deeper quakes, the seismic waves have lost more energy by the time they reach the surface. Probability probability of exceedence in 50 years pga peak ground acceleration based on intensityacceleration relationships from 1. The main features of the strong ground motion were long duration of strong ground shaking. For the peak hour factor phf if you have actual hourly counts, use may use that phf to enter into this screen.
This particular data set is for peak ground acceleration with a 10 percent probability of exceedance in 50 years. The national earthquake ground motion map used in the existing aashto provisions is a probabilistic map of peak ground acceleration pga on rock that was developed by the u. The purpose of this paper is to present the pgam and spectral acceleration for makassar city based on a probabilistic approach. A hybrid computational approach could be optimized by combining more than one soft computing technique. Estimation of peak ground acceleration and spectral. The goal of the study is to analyze the distributions of peak ground acceleration, velocity and displacement from 18 moderate size undercrustal earthquakes m w 4. As defined by usgs, pga peak acceleration is what is experienced by a particle on the ground. Summary a seismic hazard model for south america, based on a smoothed gridded seismicity model, a subduction model, a crustal fault model, and a ground motion model, has been produced by the u. Geologic mapping has cascades and merge with geophysical lineaments and extended the swif from the. To this reference ground motion an importance factor. Hough, tomoyo taniguchi, and jeanrobert altidor abstract the m 7. Shallow quakes tend to be much more damaging than deep quakes of comparable magnitude such as the m6.
View peak ground acceleration research papers on academia. Peak ground acceleration with a 1% probability of exceedance. Estimation of peak ground acceleration from horizontal rigid. For at least 290 of the 671 additional observations identified for this study i. Method of combining components should be taken into consideration to. In december 2000, a tectonic event occurred in the southern part of the netherlands near the city of voerendaal. The peak acceleration is the largest increase in velocity recorded by a particular station during an. In fact, the true measure is pseudospectral acceleration, which is equal to. Peak ground acceleration pga is equal to the maximum ground acceleration that occurred during earthquake shaking at a location. Procedure to estimate maximum ground acceleration from. Peak ground acceleration with a 10% probability of exceedance. Estimation formulas for peak ground acceleration amax and effective ground acceleration ae, used with the jma scale of seismic intensity.
Global earthquake peak ground acceleration hazard distribution. Peak ground velocity pgv has received much less attention in the technical literature than more widelyused parameters such as peak ground acceleration pga and response spectral ordinates. Pdf the goal of the study is to analyze the distributions of peak ground acceleration, velocity and displacement from 18 moderate size undercrustal. Procedures for estimating earthquake ground motions usgs.
Variation in groundmotion response spectra and peak ground acceleration values for the same value of. Estimation of peak ground acceleration from horizontal. The peak acceleration is the largest increase in velocity recorded by a particular station during an earthquake. Relationship between peak ground acceleration, peak ground velocity, and intensity in taiwan 389 figure 3. Fannie mae peak ground acceleration home client types fannie mae peak ground acceleration the 2014 update of the fannie mae multifamily selling and servicing guide for property needs assessments pna has been revised to include a determination of site seismic hazard using the 475year 10% in 50year peak ground acceleration. Ninety five threecomponent records from 15 ground motions that occurred in northwestern turkey between 1999 and 2001 were used.
Scaling of peak ground acceleration and peak ground velocity. The view of seismic hazard in the halmahera region aip publishing. Recent studies sponsored by the south carolina department of transportation scdot have shown that f pga, and other spectral site. Technically, then, acceleration is how much the velocity changes in a unit time. Effect of high peak ground acceleration on the liquefaction. The equations examined in the regression analysis have the following general form. For each seismic zone the reference peak ground acceleration, a gr, corresponds to the reference probability of exceedance in 50 years, p ncr, of the seismic action for the nocollapse requirement. Gis map can clearly reveal the high peak ground acceleration pga effect on subsoil. The seismic hazard map of the americas depicting peak ground acceleration pga, given in units of ms 2, with a 10% chance of exceedance in 50 years. Effective horizontal peak ground accelerations a a for rock soil profile b, see 2. Attenuation characteristics of peak ground acceleration. Liquefaction hazard maps are useful tools for identifying areas with high likelihood of liquefaction induced ground deformation, a major cause of damage in many earthquakes 8. Eeri empirical groundmotion models for the rotationindependent average horizontal component from shallow crustal earthquakes are derived using the peer nga database.
Hybrid artificial neural networksimulated annealing. Today i managed to get an honorable mention skip to 12. The map provides contours of pga for a probability of exceedance pe of 10% in 50 years, which corresponds to approximately 15%. Scaling of peak ground acceleration and peak ground. Attenuation characteristics of peak ground acceleration from. Peak acceleration general discussion car talk community. The site classification is rock everywhere except canada and the united states, which assume rockfirm soil reference ground conditions. Attenuation relationships for peak horizontal ground acceleration for short. For other types of soil profile these values are scaled by a factor f a. Prediction of peak ground acceleration using esvr, nsvr and lssvr algorithm sonia thomas a, g.
Where y is the peak ground horizontal acceleration, x is hypocentral distance and m is. The peak ground acceleration pga and sa values at ground surface may vary signi. Seismic hazards during many disastrous earthquakes are observed to be aggravating at the sites with the soft soil deposits due to amplification of ground motion. Global earthquake hazard distributionpeak ground acceleration is a 2. Pga records the acceleration rate of change of speed of these movements, while peak ground velocity is the greatest speed rate of movement reached by the ground, and peak displacement is the. Pga records the acceleration rate of change of speed of these movements, while peak ground velocity is the greatest speed rate of movement reached by the ground, and peak displacement is the distance moved. Earthquake energy is dispersed in waves from the epicentre, causing ground movement horizontally in two directions and vertically. Peak ground velocity pgv the peak ground velocity during an earthquake measured in units of cmsec cgs peak ground displacement pgd the peak ground displacement during an earthquake measured in units of cm cgs. Peak ground acceleration with a 10% probability of. Empirical correlation equations between peak ground acceleration, spectral acceleration, spectrum intensity, and acceleration spectrum intensity are developed. During an earthquake when the ground is shaking, it also experiences acceleration. Peak ground acceleration pga and spectral acceleration sa are commonly used in terms of expressing earthquake hazards. Earthquake energy is dispersed in waves from the hypocentre, causing ground movement omnidirectionally but typically modelled horizontally in two directions and vertically. Free field surface motion at different site types due to near.
Free field surface motion at different site types due to. Analysis psha aims to quantify these uncertainties, and combine them to produce an. Peat ground acceleration seismic map 10% in 50 years excecdance explanation peak acceleration, expressed as a fraction of standard gravity g 0. Peak ground acceleration can be expressed in g as either a percentage. This change from one speed, or velocity, to another is called acceleration. Pillaib and kirat pal adepartment of earthquake engineering, indian institute of technology, roorkee, india. Values of peak horizontal ground velocity and displacement derived from accelerograms of past earthquakes and. In this study, liquefaction hazard has been assessed for an area developed. The higher of these two values represents the mce acceleration used as a design input to the stabilitydeformation. When the ground is shaking during an earthquake, it also experiences acceleration. Every friday he does a video responding to some of the comments. Jan 23, 2017 pga records the acceleration rate of change of speed of these movements, while peak ground velocity is the greatest speed rate of movement reached by the ground, and peak displacement is the.
This can be measured at or specified for different oscillation frequencies and with different degrees of. Pga records the acceleration rate of change of speed of these movements, while peak ground velocity is the greatest speed rate of movement reached by the ground, and peak. Evaluation of groundmotion modeling techniques for a. To determine the design mce ground motion, the deterministic peak horizontal ground acceleration from nearby fault sources is compared to that from the background earthquake. The correlation equations are developed for shallow crustal earthquakes using the next generation attenuation nga ground motion database, and four of. Medvedev 1968 for mmi ix level ground motions, shepherd and aspinall 1980 estimated an acceleration of 32% g with a 30% probability of exceedence in 50 years on hard. Pga is equal to the amplitude of the largest absolute acceleration recorded on an accelerogram at a site during a particular earthquake. The characteristics of strong ground motion, the site category, depth of the soil column, type of rock strata, and the dynamic soil properties at a particular site significantly influence the free field motion during an earthquake.
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