The spectrum can be used in the subsequent response spectrum analysis, or it can be written to a file for future use. University of california, berkeley civil and environmental. Seismic response spectrum gui file exchange matlab central. This record is also attached to the submitted files. Practical guidelines to select and scale earthquake. 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 following documents in the nureg series are available for purchase from the gpo sales. Nov 27, 2018 earthquake cleanup and response resources an earthquake is a sudden movement of the earth characterized by rapid shaking which is produced as a result of rock movement beneath the earths surface. Response spectrum analysis of concrete gravity dams.
Construction of design response spectrum the chilean way eps 256 rodrigo music when you are designing an earthquake resistant structure someimportantquestionsare. The resulting plot can then be used to pick off the response of any linear system, given its natural frequency of. Records for nonlinear response history analysis of structures by erol kalkan and anil k. This motion is created to develop the crs at the equipment attachment point. Response spectrum analysis of concrete gravity dams including. T o solve this problem, earthquake response spectrum analysis is the most wellknown tool in the seismic analysis of the str uctures. Earthquake response spectrum analysis of 4 story shear building. Earthquake response spectrum analysis of 4 story shear. This function generates elastic response specra including displacement spectrum, pseudo acceleration spectrum, and pseudo velocity spectrum which are needed in a response spectrum analysis of structures.
The results prove that buildings with severe irregularity are more vulnerable than those with regular configuration resulting from torsion behavior, and the additional shear force produced in the perpendicular direction to the earthquake input. The response spectrum issued by the user as part of the specifications for. The first data reported from an earthquake record is generally the peak ground acceleration pga which expresses the tip of the maximum spike of the acceleration ground motion figure 1. Response spectrum method of analysis with simplified. The user may select from a list of different standard response spectra. An earthquake is a sudden movement of the earth characterized by rapid shaking which is produced as a result of rock movement beneath the earths surface. Its origin probably dates from civil engineering and the problem of seismic excitations, i. The user can change the input parameters to construct a sitespecific response spectrum considering different hazard conditions. Earthquake acceleration time history and response spectra design are needed as basis to determine the earthquake loading that can be used to design and assess the tall building and other structures. 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. Figure 3 shows the lower half of the earthquake acceleration response spectrum that we will use for the analysis. Seismic design forces for foundations, other than pile bents and retaining walls, shall be determined by dividing elastic seismic forces, obtained from article 3. The selection ec1 refers to type 1 and ec2 refers to type 2. Given waveform data and instrument response files, pqlx server calculates trace statistics, power spectral densities psd, and probability density functions pdf and writes the results to a mysql database for quick access.
Construction of design response spectrum the chilean way. Methodology for developing design response spectrum for. Seismic design of buildings geotechnical aspects jean louis locsin january 27, 2018 outline introduction. First column is time and second column is acceleration in g. Software to download usgs earthquake hazard program. According to the eurocode two types of response spectra are possible. Some concepts in earthquake behaviour of buildings c. 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. An accelerogram can be integrated to obtain the time variations of the ground velocity and ground displacement. Response spectrum analytical tool zplot of response acceleration to an earthquake ground acceleration input ztheoretical response of sdof oscillators to input zapplied to dynamic modal analysis zcalculated theoretical response not actual response to shake table input acceleration to determine if test input is sufficient. Modal response spectrum method means a method of dynamic analysis in which a given earthquake design spectrum is applied to a mathematical model of the structure and the response of several modes are determined, and combined. It offers a simplified method for finding the design forces for structural members for. A plot of the peak value of a response quantity eg.
Earthquake response spectrum analysis of 4 story shear building shear building modal analysis earthquake response spectrum modal spectral accelerations modal displacements floor displacements story drifts inertia forces shear forces overturning moments input and output files in this example we compute the displacements, shear forces, story drifts. The resulting plot can then be used to pick off the response of any linear system, given its natural frequency of oscillation. R2 usgs requests that the earthquake hazard community bring to our attention new earthquake source and ground motion data or models that could be included in the national seismic hazard model nshm updates. The earthquake response spectrum is a fundamental quantity in earthquake engineering and in aseismic design of structure and it is one of the key tools applied. The acceleration time history and response spectra design for certain site can be acquired using the seismic hazard analysis, amplification of ground motion quantity, and. The earthquake ground motion and response spectra design for. The trs shall envelope the rrs with limited exceptions. Five matlab files are written to perform the analysis. Therefore, it enables the user to calculate the peak ground acceleration pga and pseudo velocity. The method presented in the course is widely used and is applicable to any structure or equipment that can be modeled as a singledegreeoffreedom sdof system. How to estimate the maximum forces generated by the. Correlation between ground motion and building response using. Seismic hazard curves and uniform hazard response spectra for.
Cdc earthquake response niosh workplace safety and. Seismic hazard curves and uniform hazard response spectra. Earthquake simulation definitions zresponse spectra. Empirical earthquake recordings enable characterization of a sites earthquake response behavior. Scaling involves applying a constant factor to individual pairs of horizontal ground motion records to make their response match the design spectrum at a single period or over a range of periods. The next update of the nshm for the conterminous u. The earthquake response of an actual dam to an ensemble of 58 ground motions, selected and scaled to be consistent with a target spectrum determined from a probabilistic seismic hazard analysis for the dam site, was determined by the rha procedure. Seismic design maps from various design code reference documents are available below as pdf files.
Geological survey editorial standards or with the north american stratigraphic code. For each damping value the magnitude of the response spectrum must be given over the entire range of frequencies needed, in ascending value of frequency. Objectives earthquake hazards earthquake structural damage ground failure fire. The earthquake ground motion and response spectra design. It allows a clear understanding of the contributions of different modes of vibration. Therefore, we can generate a response spectrum for that earthquake. This script aims to offer the shock response spectrum of an acceleration time history of an earthquake which is known.
We are interested in the maximum relative displacement, velocity, and total accelerations. Seismic hazard curves and uniform hazard response spectra for the united states by a. Response spectrum method is favoured by earthquake engineering community because of. To overcome the above difficulties, earthquake response spectrum is the most popular tool in the seismic analysis of structures. It provides a technique for performing an equivalent static lateral load analysis. Response spectrum analysis massachusetts institute of. To solve the equation of motions for different periods, the newmark linear method was used.
The acceleration response spectrum developed by the motion of the shake table to provide an input motion that simulates an earthquake for the qualification of equipment. The standard method used in design is the modal response using a design spectrum. Vibrationdata programs to calculate shock response spectrum. Elastic response spectrum file exchange matlab central. The response spectrum model stipulated in the current australian earthquake loading standard as 1170. This spectrum were done taking as a start point normalized version of the response spectra obtained from different accelerograms recorded for the following earthquakes. Earthquake design spectra given a earthquake ground acceleration, there is no difficulty to compute response using newmarks method as the previous example. It also plots the solution and stores them in a file allowing certain changes such as the acceleration unit. In addition, workshops are held for feedback and comments. Such a procedure will be valid only to the extent that the shape of the response spectrum is independent of earthquake magnitude, source distance, and recording site conditions. The software consists of a server and client but also includes data extraction and manipulation tools. Several methods can be used to analyse the response of a structure subjected to an earthquake. Sep 10, 20 response spectrum method is favoured by earthquake engineering community because of. 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.
Earthquake response spectrum analysis of 4 story shear building shear building modal analysis earthquake response spectrum modal spectral accelerations modal displacements floor displacements story drifts inertia forces shear forces overturning moments input and output files in this example we compute the. The course presents the response spectrum method of earthquake response analysis of simple structures and mechanicalelectrical equipment. Pdf this report is the development of response spectrum analysis for mdof. Performing ollanization name and address earthquake engineering research center university of california, richmond field station 47th and hoffman blvd. The shock response spectrum srs allows to estimate transient acceleration signals in terms of a maximum response of a dynamic vibration system. Design response spectra are often provided in terms of the period, rather than the frequency. Requirements for seismic qualification of hvacr equipment.
Spectrum matching ba minimum base shear r 5 r 1 01 234. Residual displacement prediction of rc building structures using earthquake response spectra r1 to r5 satisfy the following relation. The flat hyperbolic x r response spectrum shape is based on observations of moderate and large magnitude. The design response spectrum is the actual input to the response spectrum analysis. Since one is the inverse of the other, the two graphs are just mirrored when plotting on a logarithmic scale. Response spectra of elcentro earthquake it is desired to obtain the elastic response spectra of ns component of 1940 elcentro earthquake fig. Create scripts with code, output, and formatted text in a single executable document. The acceleration response spectra is represented as piecewise linear segments, whose endpoints are defined by a time, acceleration coordinate.
Response spectra horizontal directions the most important step is the definition of the response spectrum. Response spectrum of any earthquake ground motion is simply a plot of the maximum response during that earthquake of a single degree of freedom sdf system as a function of its natural vibration period t n or frequency w n or f n, for a. Modelling of earthquake response spectra for strike slip. The acceleration time history and response spectra design for certain site can be acquired using the seismic hazard analysis, amplification of. 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. Earthquake analysis and design of simple structures and. Cdc earthquake response niosh workplace safety and health. Methodology for developing design response spectrum for use. Earthquakes are associated to multiple hazards that represent a risk for emergency responders and recovery workers.
The user can change the input parameters to construct a sitespecific response spectrum. Geological survey editorial standards and stratigraphic nomenclature abstract we have developed empirical equations for predicting earthquake response spectra in terms of magnitude, distance, and site conditions, using a twostage regression. The choice of method depends on the structure and on the objectives of the analysis and include. A plot of the maximum response, as a function of oscillator frequency, of an array of singledegreeoffreedom sdof damped oscillators subjected to the same base excitation. Note that the design earthquake response spectrum represents elastic response of a singledegreeoffreedom oscillator with 5% of critical damping subjected to ground shaking with approximately 475year return period. The data from these maps can be read more easily using.
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