Earthquake ground motion and response spectra springerlink. Introduction transition from sni gempa 2002 to sni gempa 201x sni gempa 2002 sni gempa 201x overview on seismic response spectrum generating design response spectrum using the new seismic map mapped spectral acceleration at mce level 2500 yr earthquake spectral acceleration at dbe level. Median responses are estimated for all 6 plus 10 16 record sets. Methods of ground motion recording and correction are first presented, followed by a discussion of ground motion characteristics including peak ground motion, duration of strong motion, and frequency content. Procedures and examples for developing an acceleration response spectrum ars are based on the current criteria in the sdc, appendix b, and require the user to be familiar with the ars online report, caltrans fault database, ars online web tool, andthe deterministic response spectrum spreadsheet. In this study the aim is to analyze the response of a highrise structure to ground motion using response spectrum analysis. Using the information gathered in the preceding input the data into steps, cb the model cy inputs section of the deterministic response spectrum spreadsheet shown below todevelop the deterministic ars for each fault. The response spectrum method of analysis is developed using the following steps. A design response spectrum has been developed based on cam for a peak ground velocity pg v of 60nunsec.
Jennings abstract a numerical method for computing response spectra from strongmotion earthquake records is developed, based on the exact solution to the governing differential equation. Displacement and acceleration design spectra for seismic isolation systems in christchurch 2014 nzsee conference d. Response spectrum method of analysis shall be performed using the design spectrum specified in clause 6. It is nearly identical to the true total acceleration response spectrum for lightly damped structures. The details of ground motions and their characteristics considered for the analys are presented in table 1. The representation of the maximum response of idealized single degree freedom system having certain period and damping, during earthquake ground motions. Different models, that is, bare frame, brace frame and shear wall frame are considered in staad pro. Used in this manner the spectrum technique represents an approach intermediate between a design based on static loads and a complete integration of the equations of motion of. The resulting plot can then be used to pick off the response of any linear system, given its natural frequency of oscillation. The earthquake ground motion and response spectra design for. Why response spectrum approach in earthquake geotechnical engineering. May, 2011 the science of strong ground motion may use some values from the ground response spectrum calculated from recordings of surface ground motion from seismographs for correlation with seismic damage. Response spectrum analysis is the dominant contemporary method for dynamic analysis of building structures under seismic loading.
Response spectrum modal superposition analysis can also help engineers design components for nuclear power plants, such as nuclear reactor parts, pumps, valves, piping, and condensers. Input parameters into deterministic response spectrum spreadsheet. Presentation on response spectrum analysis as per indian code. Traditional approaches for the prediction of earthquake actions using design response spectra rely on accurate hazard models for the region concerned, which in turn depend heavily on the availability of strong ground motion data. If the input force is arbitrary, we can find the response spectrum only numerically. This spectrum were done taking as a start point normalized version of the response spectra obtained from different accelerograms recorded for the following earthquakes. A responsespectrum analysis calculates the maximum response of a structure to transient loads such as displacement,velocity or acceleration, that are forced into vibration by a base vibration or shock. Datta department of civil engineering, iit delhi response spectrum method of analysis 0 5 10 15 20 25 30 0. Timehistory method the sdof response spectrum method can be used as long the structure or equipment can be modeled by a single degree of freedom system consisting of a spring, mass and damping. Sgs s eismic data g eneration s ystem extracts and plots graphs of earthquake history records, seismic response spectrums and design response spectrums using the midas family programs builtin earthquake databasebuiltin earthquake history records about 30 earthquake records in north america from 1940 until 1990. Construction of design response spectrum the chilean way.
Seismic analysis of high rise building by response. Aug 14, 2015 earthquake analysis by response spectrum method 1. Reinforced concrete frames are the most commonly adopted buildings construction practices in india. The sdof response spectrum method usually gives less conservative results than simplified procedures, yet easy to. Response spectrum method of analysis with simplified. Earthquake analysis and design of simple structures and. Generation of responsespectrumcompatible artificial. Mar 11, 2017 a response spectrum analysis calculates the maximum response of a structure to transient loads such as displacement,velocity or acceleration, that are forced into vibration by a base vibration or shock. An example of smooth spectra is shown in figure 4 based on a building code design response spectrum for a site of high seismicity.
The response spectrum modal superposition analysis uses formulae recommended by the u. Third, the structure in question is subjected to a nonlinear dynamic analysis under each of the many records. The method presented in this course is widely used and is applicable to any structure or equipment that can be modeled as a singledegreeoffreedom sdof system. Pdf reliability analysis of uncertain structures using. To help engineers design sound structures, response spectrum modal superposition analysis is used with information gathered. The results from the mrs analysis are compared with the results obtained from an equivalent lateral force elf analysis of the same frame. The procedure that has been used by nicolaou 1998 was utilized also here to obtain the earthquake acceleration time history for sleman, yogyakarta, indonesia. Methodology the design lateral shear force at each floor in each mode is computed by staad in accordance with the is. The paper extends previous work by the authors on displacement and acceleration spectra for analysis and design of. Engineers use response spectrum modal superposition analysis to determine the structural response to sudden forces or shocks such as an earthquake. The map is based on the most recent usgs models for the conterminous u. Response spectrum modelling for regions lacking earthquake. In the case of large multistoried buildings the response at different levels vary due to different factors in dynamic load and lateral load, therefore it is necessary to determine the response at different floors for efficient design.
Floor response spectra generation for seismic design of. Hence, it is essential to consider the seismic load for the design of multistoried building. In the 250 page eeri document he never indicated he used the response spectrum method for his research or professional. The seismic analysis with response spectrum allows to obtain the maximum joint displacements, forces in members and support reactions for an earthquake. Natural period of embankment subsoil system the model of embankment subsoil system shown in fig. Response spectrum provisions in the current australian earthquake loading standard as 1170. Methodology for developing design response spectrum for. The science of strong ground motion may use some values from the ground response spectrum calculated from recordings of surface ground motion from seismographs for correlation with seismic damage. For earthquake loads, you define one or more response spectra and apply them in a specified direction over part or all the piping system. Eurocode 8 compliant real record sets for seismic analysis of. This chapter uses the modal response spectrum mrs method of analysis to examine a sixstory momentresisting frame. This third lecture by timurhan timur explains the concept of response and. In a response spectrum analysis, the results of a modal analysis are used in terms of a known spectrum to calculate displacements and stresses in the model. Comparative study of static and dynamic seismic analysis.
In order to calculate the acceleration and displacement response spectrum using the nga. Displacement and acceleration design spectra for seismic. Brief history of computation of earthquake response spectra m. Abstract an evaluation is made of response spectrum techniques as applied to seismic analysis and design of steel template offshore platforms. Floor response spectra generation for seismic design of buildings. Brief history of computation of earthquake response spectra. Nevertheless, response spectrum has become standard terminology. Instructional material complementing fema p751, design. Floor response spectrum method for seismic analysis of multiply. New zealand acceleration response spectrum attenuation. During an earthquake, violent shaking is transmitted into a structure at the points where it is attached to the ground. In the case of large multistoried buildings the response at different levels vary due to different factors in dynamic load and lateral load, therefore it is necessary to determine the response at.
Ibc 2000 design response spectrum eurocode8, 1996 design response spectrum china gb500112001 design response spectrum japan aij, 2000 design response spectrum. This chapter surveys the stateoftheart work in strong motion seismology and ground motion characterization. Determining the response spectrum from a given set of accelerograms is quite a wellcodified procedure. The response spectrum of the earthquake acceleration is defined as being the maximum of the spectral response according to the period t. These methods range from stochastic simulation boore, 2003 of point or finite sources to dynamic models of rupture. Spectrum time history definitions tab spectrum time history load cases tab staticdynamic combinations tab lumped masses tab snubbers tab control parameters tab advanced tab. Introduction the most direct description of an earthquake motion in time domain is provided by accelerograms that are recorded by instruments called strong motion accelerographs. The flat hyperbolic x r response spectrum shape is based on observations of moderate and large magnitude. Modal analysis is performed to identify the modes, and the response in that mode can be picked from the response spectrum. The accelerograph records three orthogonal components of ground acceleration. Seismic analysis of high rise building by response spectrum. With growing economy, urbanisation and unavailability of horizontal space increasing cost of land and.
The peak displacement response of an undamped sdof system subjected to a. Using the acceleration response spectrum, an equivalent static load is derived which will provide the same maximum response as that obtained in each. Specifically, the safe shutdown earthquake ground motion sse for these nuclear power plants is defined by a rg 1. The very first response spectrum was proposed by benioff in 1934 and again in 1943 by m. Response spectrum method in seismic analysis and design of. New developments in the response spectrum method have led to calculations in seismic stresses that are more accurate, and usually lower, than those obtained by conventional methods. The earthquake loading is assumed to be described in terms of response spectra. Earthquake hazard map showing peak ground accelerations having a 2 percent probability of being exceeded in 50 years, for a firm rock site. Aug 05, 20 this is a tutorial for seismic analysis by response spectrum method using ecp 2012 egyptian code presented by eng.
Eurocode 8 compliant real record sets for seismic analysis. Select the detailed menu corresponding to the design response spectrum to be generated to display the following design response spectrum data entry dialog box. Record selection for nonlinear seismic analysis of structures. Seismic analysis of highrise building using response. On the other hand the generation of the accelerograms from the knowledge of a target response spectrum is an inverse problem whose solution is not unique.
Response spectra blume and associates engineers, 1973 on the basis of a number of significant records accelerograms of major earthquakes that occurred during 19341966 provided a standardized design spectrum shape to be used in the seismic design of nuclear power plant facilities in the us concept sa. The response spectra database has been compiled from hundreds of groundmotion recordings from subduction earthquakes of moment magnitude m 5. The procedure is based on minimizing the differences between the target spectrum and ath response spectrum in a least square sense. The main reasons for the widespread use of this method are. Earthquake response spectrum analysis caesar ii help.
Response spectra blume and associates engineers, 1973 on the basis of a number of significant records accelerograms of major earthquakes that occurred during 19341966 provided a standardized design spectrum shape to be used in the seismic design of. Sep 10, 20 the response spectrum method of analysis is developed using the following steps. If the input used in calculating a response spectrum is steadystate periodic, then the steadystate result is recorded. Mar 22, 2014 presentation on response spectrum analysis as per indian code.
The maximum response plotted against of undamped natural period and for various damping. To interpret the effects of an earthquake on structures a response spectrum is used. Development of earthquake energy demand spectra ahmet an. Response spectrum method and time history analysis are widely used in the seismic design of buildings. Calculates the acceleration, velocity and displacement time series for. This spectrum has been shown to produce conservative structural responses, because occurrence of an extreme sat spectral acceleration at period t. Response spectra using duhamels integral in the above examples, the input force is simple and hence a closed form solution has been obtained for the response spectrum. A response spectrum is a plot of the peak or steadystate response displacement, velocity or acceleration of a series of oscillators of varying natural frequency, that are forced into motion by the same base vibration or shock. The median of each of the arbitrary sets is compared with each of the target sets 6. This paper develops a probabilistic methodology for the seismic reliability analysis of structures with random properties. Hays, 1980 proposed it as a different method for determining the maximum amplitudes of response of ensemble of simple damped harmonic oscillators. It is assumed that the acceleration responses for two orthogonal components be independent in the elastic response because the effect of bilateral bending on the structural response is generally small.
Eurocode 8 compliant record sets for seismic analysis of structures 55 simulation records 2 are ob tained via modeling of the seismological source and may account for path and site effects. Rational design spectra for structural reliability assessment using. By superposition of different modes of response, spectrum techniques can be applied o the design and analysis of complex structures such as buildings and dams. For each mode, a response is read from a design spectrum based on the modal frequency and a given damping ratio. The earthquake ground motion and response spectra design. Seismic analysis of highrise building using response spectrum method pratik bawankar1 1g. This is a tutorial for seismic analysis by response spectrum method using ecp 2012 egyptian code presented by eng. Methodology for developing design response spectrum for use. Response spectrum method of analysis mechanical engineering. Staad v8i earthquake analysis by response spectrum 1. Enter value of input spectrum x 2 x work out manually e. Applications of these methods is essential in the seismic design of critical structures, such as nuclear power plants and petroleum facilities.
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