Fema 356 pushover analysis

Nonlinear static monotonic pushover analysis has become a common practice in performancebased bridge seismic design. Pushover analysis, fema 356, eurocode 8, seismic assessment, plastic rotation, limit states. Figure 22 fema 356 performance levels taken from fajfar et al. The role of higher mode pushover analyses in seismic analysis of buildings is examined in this paper. Mar 31, 2014 both pm2m3 hinges and fiber hinges are available to capture coupled axial and biaxialbending behavior. The aforementioned nonlinear static procedures fema 356, atc40, fema 440, ascesei 4106, csmn2 usually require the pushover analysis.

In general, the method is able to reproduce the essential response features providing a reasonable measure of the likely contribution of higher modes in all. Seismic assessment of rc building according to atc 40, fema. A variety of existing pushover analysis procedures are currently being consolidated under programs such as atc 40 and fema 273. In this paper, a modal pushover analysis using design response spectra of ubc 97 is proposed. Prior preparatory steps, however, were much needed, as was noted in the 1985. Fema 273 nehrp guidelines for the seismic rehabilitation. Seismic design aids for nonlinear pushover analysis of. Pushover analysis is carried out for either userdefined nonlinear hinge properties or defaulthinge properties, available in some programs based on the fema 356 and atc40 guidelines.

The structure is pushed statically to a target displacement at the control node to check for the acceptable structural performance. The title of this document, fema 356 prestandard and. Pushover analysis is carried out for either userdefined nonlinear hinge properties or defaulthinge properties, available in some programs based on the fema 356 such as sap2000. The popularity of pushover analysis is due to its ability to identify the failure modes and the design limit states of bridge piers and to provide the progressive collapse sequence of damaged bridges when subjected to major earthquakes. The results demonstrate the accuracy of the ecmp procedure. It is widely accepted that, when pushover analysis is used carefully, it provides useful information that cannot be obtained by linear static or dynamic analysis procedures. The pushover analysis, explained in its simplicity rahul leslie1, assistant director, buildings design, driq board. The static pushover analysis is becoming a popular tool for seismic performance evaluation of existing and new structures. The distribution can also be proportional to either the first mode shape, or a combination of modes. Fema 356 2 2000 displacement coefficient method dcm. Fema356 per mits this procedure even for buildings with signi. Hinge technical knowledge base computers and structures. Sap2000 provides default hinge properties and recommends m3 hinges for columns and m3 hinges for beams as described in fema 356 19. Therefore, extensive use is made of fema356, prestandard and commentary for seismic rehabilitation of buildings.

Application of pushover analysis to the design of structures. In pa, in the global sense, it is the base shear vb vs roof top displacement. Threedimensional modeling and analyses of the buildings were performed in accordance with the fema 356 methodologies for linear static, linear dynamic response spectrum, nonlinear pushover, and nonlinear rime history analysis procedures. Lateral load distribution factor for modal pushover analysis. Pushover analysis method based on fema356 download. The design is governed by the 2001 california building code cbc. Seismic assessment of rc buildings according to fema 356. Download scientific diagram pushover analysis method based on fema356 from publication. Keywords plastic hinges pushover fema 356 en 19983 capacity curve n2 method capacity spectrum method acceptance criteria. Pushover analysis is performed to produce the ultimate building capacity. Modal pushover analysis part 1 advanced structural. Fema356 pushover analysis procedures for all investigated response quantities and is a closer match to the nonlinear timehistory responses. Conventional pushover analysis outlined in fema 356. It is demonstrated that the highermode pushover curves reveal plastic hinge mechanisms that are not detected by the.

The proposed method is compared against the method in. Then the ecmp procedure is evaluated by comparing the results of this procedure with nonlinear time history results as an exact solution as well as the modal pushover analysis procedure and fema 356 load patterns. It must necessary to analyze and design a structure to perform well under seismic loads and also endow with well strength, stability and ductility. Structural performance evaluation with pushover analysis case. The aforementioned nonlinear static procedures fema356, atc40, fema440, ascesei 4106, csmn2 usually require the pushover analysis. Nowadays pushover analysis enjoys more popularity and is involved in almost modern design codes, such as fema 356 357 2000, atc55, 2005. Then, the performance level of the building is determined based on the results from pushover and the guidelines given by fema 356. Analysis procedures to estimate seismic demands for.

November 2000 federal emergency management agency washington, d. Pushover analisis memang bukan hal yang baru, metode ini sudah banyak dikenal akhir tahun 90an dan banyak dipakai sekitar awal tahun 2000an, tentu setelah software sudah banyak yang memberikan fasilitas nonlinearitas. The purpose of this paper is to compare the methods given by these two documents. Pushover analysis is a static, nonlinear procedure using simplified nonlinear technique to estimate seismic structural deformations. Comparison of seismic demands determined by nonlinear. Fema 310 handbook for the seismic evaluation of buildings. Summary and application example this document records in detail an effort to assess current nonlinear static procedures nsps given in fema 356 and atc40 for the seismic analysis and evaluation of structures. Pushover analysis transforms a dynamic problem to a static problem. The pm2m3 hinge is best suited for nonlinear static pushover, whereas the fiber hinge is best for hysteretic dynamics.

Pushover analisis memang bukan hal yang baru, metode ini sudah banyak dikenal akhir tahun 90an dan banyak dipakai sekitar awal tahun 2000an, tentu setelah software sudah. Performance levels of the buildings are specified according atc40, fema 356, and fema 440. Pushover analysis of steel structure using staad tn. Pushover analysis of steel frame structures with different. Static pushover methods explanation, comparison and. Nowadays pushover analysis enjoys more popularity and is involved in almost modern design codes, such as fema 356357 2000, atc55, 2005. Nsp or pushover analysis, described in fema356 1and atc40 2. Additional information on hinges can be found in the csi analysis reference manual frame hinge properties, page 1. Fema 440 improvement of nonlinear static seismic analysis procedures 101 10.

The purpose of this paper was to evaluate the performance of the buildings, which were design according to sbc, using pushover analysis. Fema 356 lsp can be applied to simple structures using 1. The pushover analysis from basics presented by rahul leslie 41. Fema 356 2000 prestandard and commentary for the seismic. In accordance to fema 356 1, at least two load patterns. Pushover analysis of retrofitted reinforced concrete buildings. Different heightwise distributions of lateral loads are usually considered. Structural performance evaluation with pushover analysis. Whenever an analysis of the new information disclosed significant advances or improvements in the stateofthepractice, they were included in this volume. Federal emergency management agency, fema356 2000 prestandard and commentary for seismic rehabilitation of buildings, washington dc. Investigation of effects of capacity spectrum method on performance evaluation of multistory buildings according to the iraqi seismic code requirements. The pushover analysis from basics presented by rahul leslie 42. Seismic assessment of rc building according to atc 40. Fema 356 pushover analysis procedures for all investigated response quantities and is a closer match to the nonlinear timehistory responses.

Several pushover analyses are performed for six existing reinforced concrete buildings that possess a variety of natural periods. There are 4 structures cases b1, b2, c1 and c2, 4 pushover methods fema 356 coefficient method, fema 440 coefficient method, fema 440 linearization method, and capacity spectrum method and 2 levels of cyclic degradation the hysteresis loops in figs. The document is now known as asce 3102 and supercedes fema 310. Fema 356 and atc40 for the seismic analysis and evaluation. Pdf seismic assessment of rc building according to atc. A comparison of basic pushover methods semantic scholar.

Effectiveness of modified pushover analysis procedure for. Segment oa has time period ta, curve a representing the rs curve and saa is the lateral load demand, in its elastic range. Sep 26, 2014 then the ecmp procedure is evaluated by comparing the results of this procedure with nonlinear time history results as an exact solution as well as the modal pushover analysis procedure and fema 356 load patterns. Accuracy of nonlinear static procedures for estimating the. Seismic assessment of rc buildings using nonlinear static. Analysis procedures to estimate seismic demands for buildings. Effectiveness of modified pushover analysis procedure for the. Modal pushover analysis part 1 posted on 08222014 updated on 07112015. Jan 17, 2019 nonlinear static pushover analysis with useful discussion.

A further pushover analysis determination of the inelastic spectrum, performance point can then be performed, for example, in excel. The discourse follows the philosophy of performance based seismic engineering procedure better known as fema 356 nonlinear pushover analysis and using the universally acclaimed finite element method software etabs 2015. The figure also shows a simple single dof structure. Then, a comparison is made between the pushover analyses results with four new load patterns and those of fema federal emergency management agency 356 with reference to nonlinear dynamic timehistory analyses. Assessment of current nonlinear static procedures for seismic. Nonlinear static pushover analysis is a commonly used technique, which is finding prominence in standards and guidance material like eurocode 8 and fema 356. Effects of plastic hinge properties in nonlinear analysis. Seismic assessment of a rc building according to fema 356. These curves are approximately similar except multilayer shell model for all cases. Pushover analysis is in no way definitive answer to the problems of design analysis, but is an important step. Effects of plastic hinge properties in nonlinear analysis of. While such documents provide the hinge properties for several ranges of detailing, programs may implement averaged values.

In addition, the document presents approaches that were developed to improve these procedures for future application by practicing engineers. The pushover analysis based on fema 356 model and fiber model produced identical top displacementbase shear curves for the sample frames. Fema 356 2000 prestandard and commentary for the seismic rehabilitation of buildings. Pushover analysis is carried out for either userdefined nonlinear hinge properties or defaulthinge properties, available in some programs based on the fema356 and atc40 guidelines. Demand is based on matching modal pushover curves to constant ductility spectra at the pushover ductility. Role of highermode pushover analyses in seismic analysis. Pushover analysis method for performance based seismic. Prestandard and commentary for the seismic rehabilitation.

Which resources are available to perform the pushover analysis. It is an incremental static analysis used to determine the forcedisplacement relationship, or the capacity curve, for a structure or structural element. This can be evaluated using the procedures in fema 356 chap. Aydinoglu 2003 proposed displacement based pushover analysis based on equal displacement equal energy approximation also used in atc 40 and fema 440 for use in modal scaling for pushover increments. Fema 273 nehrp guidelines for the seismic rehabilitation of. However, the code provides little guidance for nonlinear analysis. Nov 14, 2016 2016 midas expert webinar pushover analysis of reinforced concrete buildings duration. Nonlinear static pushover methods for seismic analysis of structures are being. Assessment of current nonlinear static procedures for. Nonlinear static analysis pushover assumes that response is governed by a single mode of vibration, and that it is constant during the analysis distribution of lateral forces applied at storey masses. Therefore, the document on this page is for information purposes only. Notice american society of civil engineers asce has completed its effort to turn fema 310 into a national consensusbased standard. On sa, the analysis results are always the elastic limit state forces moment, shear and axial forces to be designed for. This document records in detail an effort to assess current nonlinear static procedures nsps given in fema 356 and atc40 for the seismic analysis and evaluation of structures.

Effects of building configuration on seismic performance of rc buildings by pushover analysis. Federal emergency management agency fema 356 november 2000 prestandard and commentary for the seismic rehabilitation of buildings prepared by american society of civil engineers reston, virginia prepared for federal emergency management agency washington, d. Both pm2m3 hinges and fiber hinges are available to capture coupled axial and biaxialbending behavior. Pushover analysis option will allow engineers to perform pushover analysis as per fema 356. Steel is by far most useful material in construction and played an important role in last few decades. Pushover analysis of steel structure using staad tn ram.

Therefore, extensive use is made of fema 356, prestandard and commentary for seismic rehabilitation of buildings. Seismic assessment of a rc building according to fema 356 and. In both sa and pa, the maximum lateral load estimated for the structure is calculated based on the. Seismic capacity assessment of existing rc buildings in. Since 1984, when the federal emergency management agency fema first began a program to address the risk posed by seismically unsafe existing buildings, the creation of these guidelines has been the principal target of femas efforts. Performance levels of the buildings are specified according atc40, fema356, and fema440. This paper comprehensively evaluates the modal pushover analysis mpa procedure against the exact nonlinear response history analysis rha and investigates the accuracy of seismic demands determined by pushover analysis using fema356 force distributions. The peak deformed shape along the heights of the buildings show that fema 356 pushover envelope consistently overestimates the peak story displacements in the low and intermediate story levels for all buildings and ground motions types investigated, while ubpa underestimates the displacements at almost all levels with the exception of the upper. Pushover analysis method for performance based seismic design. Topics varied considerably, but typically covered approaches, methodologies, and criteria. The fema356, mmpa, ubpa and amc nonlinear static procedures are evaluated by comparing the computed roof drift ratio maximum roof displacement normalized by building height, interstory drift ratio relative drift between two consecutive stories normalized by story. Prestandard and commentary for the seismic rehabilitation of buildings fema 356. Fema 310, handbook for the seismic evaluation of buildingsa prestandard. The proposed method is compared against the method in fema 273 and results of time history analysis keywords.