Structure design using response spectrum pdf

Now, it is necessary to construct the design response spectrum. Rational design spectra for structural reliability assessment using. Thus one need a way to combine the individual modal responses to get the combined response of the structure. Analysis and design to a range of international codes including specialist seismic requirements. A comparative analysis on absolute and srss methods of.

The objective of the project is to carry out response spectrum analysis rsa of regular and irregular rc building frames and time history analysis tha of regular rc building frames and carry out the ductility based design using is 920 corresponding to response spectrum. Response spectrum method in seismic analysis and design of. It can also make use of various forms of dynamic analysis from modal extraction to time history and response spectrum. It can be inferred that the response spectrum load case being unsigned quantity when added with other gravity load cases yields huge unsigned axial forces which is treated as tensile force in the design. The method involves the calculation of only the maximum values of the displacements and member forces in each mode using smooth design spectra that. Design output for the column considering signed response spectrum results. Response spectrum analysis rsa is a method widely used for the design of buildings. Dynamic analysis using response spectrum seismic loading before the existence of inexpensive personal computers, the response spectrum method was the standard approach for linear seismic analysis 15. Integrated analysis and design solution for building systems. By using signalanalysis techniques, we can measure vibra tion on the operating structure and make a frequency anal ysis. Response spectrum analysis, timehistory, pushover, staged construction, pdelta, temperature difference and seismic isolators. Analysis and design of grid slab in building using. Response spectrum analysis, timehistory, pushover, staged construction, pdelta. The structure is analyzed using etabs software and design has been done manually.

Response of the structure concept of response spectrum 1 find amax it is a plot of the peak response velocity, displacement. The objective of the project is to carry out response spectrum analysis rsa and time history analysis tha of vertically irregular rc building frames and to carry out the ductility based design using is 920 corresponding to equivalent static analysis and time history analysis. The structures are analyzed by using methods equivalent static method of analysis and dynamic method of analysis. Table of content objective 5 problem 5 step by step 11 1. Instead of using the usual process, designers can use the signed response spectrum results. Much of the information provided herein is based on the standards of the caltrans seismic design criteria appendix b sdcb. May 30, 2018 tower design using etabs nada zarrak 1. After an estimation is made of the linear viscous damping properties of the structure, a specific response spectrum curve is selected. Current design spectra, which approximate uniform hazard or risk spectra, are known to have shortcomings, but no alternative has been proven superior for the purposes of design checks. Responsespectrum analysis rsa is a lineardynamic statistical analysis method which measures the contribution from each natural mode of vibration to indicate the likely maximum seismic response of an essentially elastic structure. Rsa procedure developed in 1950s or earlier as a means of addressing dynamic characteristics of the structural through modal analysis approach. Keywords response spectrum, grid slab, time history, nonlinear analysis and etabs. Protastructure is developed by a highly experienced. Methodology for developing design response spectrum for use.

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. This observation is used to justify the cms as a target response spectrum for design checks. A response spectrum analysis requires the specification of an excitation spectrum, also known as a frequencyacceleration spectrum. Dynamic analysis of multistory building using response. Use adequate structural model soil deformability and non strutural elements if appropriate brussels, 1820 february 2008 dissemination of information workshop eurocodes background and applications ground conditions. Abstract although response spectra have been in general use for decades by researchers, academics, and. Pdf response spectrum analysis of structures subjected. The response spectrum method of analysis is developed using the following steps. The sdof response spectrum method usually gives less conservative results than simplified procedures, yet easy to. Pdf reliability analysis of uncertain structures using.

The objective of the project is to carry out response spectrum analysis rsa of regular and irregular rc building frames and time history analysis tha of regular rc building frames and carry out the ductility based design using is 920 corresponding to response spectrum analysis. Some models are prepared that is bare frame, brace frame and shear wall frame. Pdf response spectrum analysis of structures subjected to. Sag design acceleration spectrum value t fundamental translational natural period of the building. Response spectrum analysis dynamic in stadd pro v8i on. For detailed examples of the seismicresistant design of structural steel buildings. Response spectrum method using staadpro as per the is1893 2002part1. Sep 10, 20 the response spectrum method of analysis is developed using the following steps.

This situation can be avoided by using signed response spectrum results. Response spectrum method of analysis with simplified. Response spectrum analysis rsa is a lineardynamic statistical analysis method which measures the contribution from each natural mode of vibration to indicate the likely maximum seismic response of an essentially elastic structure. Using the acceleration response spectrum, an equivalent static load is derived which will provide the same maximum response as that obtained in each. This document presents the methodologies used to develop the deterministic, probabilistic and controlling design response spectra using the web tool ars online.

Response spectrum method of analysis shall be performed using the design spectrum specified in clause 6. It requires to have the accelerogram of the design. Analysis of multistorey rcc frames of regular and irregular. This type of real physical behavior is fundamental to the design of base isolated structures. Seismic assessment and retrofitting of existing buildings using force based elastic method and nonlinear pushover analysis. Introduction one of the emerging fields in seismic design of structures is the performance based design. The modification procedure is based on adjusting each spectral value of the given design response spectrum by means of a correction factor, which depends on the structural properties and on the. The response spectrum method rsm was introduced in 1932 in the doctoral dissertation of maurice anthony biot at caltech. Structural analysis of a multistoreyed building using. This new textbook examines the wealth of information on the response spectrum method generated by the latest research and presents the background theory in simplified form. Modal transient response analysis sol 112 modal transient response analysis is another method for computing the transient response of a structure.

During an earthquake the ground shakes violently in all directions. India has been successful in meeting the food and clothing requirements of its vast population. We are interested in the maximum relative displacement, velocity, and total accelerations. This analysis mainly deals with the study of a rectangular, l, c and i shaped plan using etabs. Response spectrum method of rc frame building using etabs software duration. Response spectrum is an important tool in the seismic analysis and design of structures. In each case, the structure is modeled in three dimensions and. A plot of the peak value of a response quantity eg. Pro is one of the most widely used structural analysis and design software. Some concepts in earthquake behaviour of buildings c. Comparative study of static and dynamic seismic analysis of a. The design is focused so that the structure constructed using irregularities can safely withstand the unpredictable seismic ground motion. This section also explains the basis for the new peak ground acceleration pga maps in the 2009 provisions and asce 710 and the new equations for vertical ground motions.

The result is obtained and studied and compared to derive conclusion. Responsespectrum analysis technical knowledge base. Response spectra as a useful design and analysis tool for. Effect of soilstructure interaction in seismic analysis of. Seismic analysis of highrise building by response spectrum. Here is a list of best free structural engineering software for windows. This includes easy to use graphical methods that compare the seismic demand represented by a response spectrum to the capacity of the structure represented. 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. Ansys have a number of different mode combinations methods.

The frequency spectrum description of how the vibra. Individual mode responses are calculated using a design spectrum, and then super. Response spectrum analysis dynamic in stadd pro v8i on is1893 best explained. Selection of case study building, its response spectrum analysis and design of the full structure is presented here. Response spectrum analysis provides insight into dynamic behavior by measuring pseudospectral acceleration. Tower design using etabs nada zarrak linkedin slideshare.

Instructional material complementing fema 451, design examples seismic load analysis 9 17 1a, 1b stiffness soft story irregularity vertical structural irregularities irregularity 1a exists if stiffness of any story is less than 70% of the stiffness of the story above or less than 80% of the average stiffness of the three stories above. However, for design purposes, calculation of the duhmel integral is not always necessary. Study of seismic analysis and design of multi storey. Such spectra are called in structure response spectra or floor response spectra. A 32m x 24m 15storeys structure having 4m x 4m bays is modelled using etabs. Responsespectrum analysis provides insight into dynamic behavior by measuring. Analysis with respect to seismic activity majorly involves equivalent method and response spectrum method. Automatic calculation of codebased seismic loads using equivalent static and response spectrum analysis methods. Often, the spectral response for a range of periods is available for a local historical earthquake clough 1962 or, based on the seismic history of an area, an acceleration spectrum envelope is developed for use in structural design. Presented a parametric study on reinforced concrete rc building using response spectrum method 5. You find the response of the structure internal forces as a function of time for a specific groundmotion. This paper develops a probabilistic methodology for the seismic reliability analysis of structures with random properties. The dynamic analysis method can be performed by time history method and response spectrum method. In seismic design problems, in most occasions, it is suf.

Practical examples employing the international building code ibc regulations and. Response spectrum analysis of structures subjected to seismic actions. Seismic analysis of highrise building by response spectrum method. Jun 08, 2014 this new textbook examines the wealth of information on the response spectrum method generated by the latest research and presents the background theory in simplified form. Elastic response spectra peak response of a collection of linear singledegreeoffreedom systems with 5% viscous damping smooth spectra used for design to represent many different possible ground motion time histories 02142016 2016 asce short course sc10 8.

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. These freeware are basically used for analyzing a physical structure in terms of stability, strength, etc. The earthquake loading is assumed to be described in terms of response spectra. It supports several steel, concrete, and timber design codes. Therefore, we can generate a response spectrum for that earthquake. This response spectrum will depend on the damping ratio and thegroundmotionselected. The objective of the project is to carry out response spectrum analysis rsa of regular and irregular rc building frames and time history analysis tha of regular rc building frames and carry out the ductility based design using is 920. Pdf rational design spectra for structural reliability. The equivalence is restricted to a single mode of vibration. Earthquake design spectra given a earthquake ground acceleration, there is no difficulty to compute response using newmarks method as the previous example. For the love of physics walter lewin may 16, 2011 duration. Seismic design of buildings worked examples worked examples presented at the workshop ec 8.

In order to perform the seismic analysis and design of a structure to be built at a particular location, the actual time. Comparative study of different shapes of diagrid structure. Direct transient response analysis sol 109 in direct transient response analysis, the structural response is computed by solving the equation of motion using direct numerical integration. Structural testing part 2, modal analysis and simulation br0507. Construction of design response spectrum the chilean way eps 256 rodrigo music when you are designing an earthquake resistant structure. Response spectra as a useful design and analysis tool for practicing structural engineers sigmund a. Seismic analysis of rc regular and irregular frame structures. Dynamic analysis of the building using response spectrum method 3 building with different lateral stiffness systems. Earthquake analysis and design of simple structures and. Practical examples employing the international building code. Effect of base isolation on the response of reinforced.

Construction of design response spectrum the chilean way. Such spectra are usually provided by the architectengineer or seismic structural analyst of the building. Convert the combined maximum response into shears and moments for use in design of the structure. Based on these results, the maximum base shear is computed. He considered the design spectra recommended by indian standard code is 18932002 part i, uniform building code, and euro code8 for comparison. Dynamic analysis is carried out by using equivalent static method and response spectrum method for earthquake zone v as per indian code. When you are designing an earthquake resistant structure.

The phase information is lost in response spectrum method. This paper describes seismic analysis of highrise building using program in staadpro. Most building codes require a response spectrum analysis to evaluate the behavior of structures that are sensitive to multiplemode excitations e. Apr 24, 2016 etabs examplerc building seismic load response 1.

In this work, we use response spectrum method analysis to show that the design point associated with a structural reliability assessment is a rational choice for a design spectrum. References are provided to other resources for the use of response spectrum curves, selection and. Applications of these methods is essential in the seismic design of critical structures, such as nuclear power plants and petroleum facilities. Rational design spectra for structural reliability. Earthquake engineering, reliability analysis, earthquake engineering, fragility curves, shear wall system, flat slab structures. The findings indicate that the seismic response of the building during severe shaking may be different than that predicted during the design process, and that the expected structural demands may not be as high as predicted because of the effects of soil structure interaction and basements. Feb 18, 2016 response spectrum analysis dynamic in stadd pro v8i on is1893 best explained. Comparative study of different shapes of diagrid structure system with conventional system using response spectrum analysis jayesh akhand1, dr. In this work, we use response spectrum method analysis to show that the design point associated with a structural reliability. This includes easy to use graphical methods that compare the seismic demand represented by a response spectrum to the capacity of the structure represented by pushover forcedisplacement curves. This analysis will produce the effect of higher modes.

How to design login and register form in java netbeans. He observed from the comparative study that the response of building using is code is higher in all the cases, when compared to that of with. Pdf response spectrum analysis for irregular multistorey. Calculation of the design response spectrum in terms of spectral acceleration representing the seismic action in the horizontal or vertical direction. Seismic analyzed coefficient method analysis is done using manual calculation and response spectrum method analysis is done using staadprov8i. Equivalent lateral force for an earthquake is defined as a set of lateral force which will produce the same peak response as that obtained by dynamic analysis of structures.

Use of response spectrum analysis results in structural. Methodology for developing design response spectrum for. Yes no no yes 1 16 fema p751, nehrp recommended provisions. There are computational advantages in using the response spectrum method of seismic analysis for prediction of displacements and member forces in structural systems. Where an equivalent lateral force analysis or a modal response spectrum analysis is. If the ground acceleration from an earthquake is known, the response of the structure can be computed via using the newmarks method.

The use of s s and s 1 ground motions in the 2009 provisions and asce 710 to derive a design response spectrum remains the same as it is in asce 705. Responsespectrum analysis computers and structures. Response spectrum analysis is a linear dynamic statistical analysis method which measures the contribution from each eigenmode to indicate the likely maximum seismic response of an elastic structure. Instructional material complementing fema 451, design examples seismic load analysis 9 94 response parameters for linear response history analysis for each scaled ground motion analyzed, all computed response parameters must be multiplied by the appropriate ratio ir. Proposed changes to response spectrum analysis design. Design response spectrum required for the analysis to be used. Figure 47 shows a simplified version of a response spectrum. I do not think it would be reasonable to consider pdelta analysis with response spectrum load cases the basic reason behind this is that the results of response spectrum would loose signs as soon as the modal combination is done using methods. Designers can use the relevant command to instruct the program to use the sign of the member forces in.

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