• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.373-376
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• 2006

There are representative two performance evaluation methods for performance-based design(PBD) of reinforced concrete structures by the nonlinear static analysis, one method includes the capacity spectrum method(CSM) suggested in ATC-40(996) and the other is the displacement coefficient method(DCM) in FEMA-273(1997). The objective of this paper is to compare and verify two methods and suggest the displacement-based design for new performance evaluation of reinforced concrete structures.

• Steel and Composite Structures
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• v.41 no.5
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• pp.713-730
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• 2021

The seismic performance of rigid steel frames is widely investigated, but that of semi-rigid (SR) steel frames are not studied extensively, especially for near-field earthquakes. In this paper, the performances of five and ten-story steel SR frames having different degrees of semi-rigidity are evaluated at four performance points in the four different deformation states, namely, the elastic, elasto-plastic, plastic, and near collapse states. The performances of the SR frames are measured by the response parameters including the maximum values of the top floor displacement, base shear, inter-story drift ratio, number of plastic hinges, and SRSS of plastic hinge rotations. These response parameters are obtained by the capacity spectrum method (CSM) using pushover analysis. The validity of the response parameters determined by the CSM is evaluated by the results of the nonlinear time history analysis (NLTHA) for both near and far-field earthquakes at different PGA levels, which are consistent with the performance points. Results of the study show that the plastic hinges of SR frame significantly increase in the range of plastic to near-collapse states for both near and far-field earthquakes. The effect of the degree of semi-rigidity is pronounced only at higher degrees of semi-rigidity. The predictions of the CSM are fairly well in comparison to the NLTHA.

• Earthquakes and Structures
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• v.22 no.6
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• pp.585-595
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• 2022

Using the nonlinear static procedures has become very common in seismic codes to achieve the nonlinear response of the structure during an earthquake. The capacity spectrum method (CSM) adopted in ATC-40 is considered as one of the most known and useful procedures. For this procedure the seismic demand can be approximated from the maximum deformation of an equivalent linear elastic Single-Degree-of-Freedom system (SDOF) that has an equivalent damping ratio and period by using an iterative procedure. Data from the results of this procedure are plotted in acceleration- displacement response spectrum (ADRS) format. Different improvements have been made in order to have more accurate results compared to the Non Linear Time History Analysis (NL-THA). A new procedure is presented in this paper where the iteration process shall not be required. This will be done by estimation the ductility demand response spectrum (DDRS) and the corresponding effective damping of the bilinear system based on a new parameter of control, called normalized yield strength coefficient (η), while retaining the attraction of graphical implementation of the improved procedure of the FEMA-440. The proposed procedure accuracy should be verified with the NL-THA analysis results as a first implementation. The comparison shows that the new procedure provided a good estimation of the nonlinear response of the structure compared with those obtained when using the NL-THA analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4A
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• pp.659-675
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• 2006

Recently, significant progress has been made in performance-based engineering methods that rely mainly on nonlinear static seismic analysis procedures. The Capacity Spectrum Method (CSM) and the Displacement Coefficient Method (DCM) are the representative nonlinear static seismic analysis procedures. In order to evaluate the applicability of the procedures to the seismic evaluation and design process of new and existing structures, the accuracy of both CSM and DCM should be evaluated in advance. The accuracy of seismic responses by the nonlinear static procedures is evaluated in comparison with the shaking table test results for the structural wall specimen subjected to the far field and near field earthquakes. Also conducted are comparative studies where the shaking table test results are compared with those from nonlinear dynamic analysis procedures, i.e., Single-Degree-of-Freedom (SDOF), equivalent SDOF and Multi-Degree-of-Freedom (MDOF) systems.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.565-570
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• 2001

Base shear and roof drift relation was acquired from experiment of 3 story ordinary moment resisting frame which was designed using gravity loads. To evaluate the dynamic behavior of the frame, analytical model was generated from experimental result. Dynamic analysis was performed using the analytical model subjected to earthquake ground motions with 500, 1000, and 2400 years of return period. And capacity spectrum method was adopted to find the performance points of the frame. Both dynamic analysis and CSM showed that the performance of the frame meet the life safety objectives suggested by FEMA 273 and ATC 40.

• Earthquakes and Structures
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• v.11 no.6
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• pp.967-982
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• 2016

Current codes design the buildings based on life safety criteria. In a performance-based design (PBD) approach, decisions are made based on demands, such as target displacement and performance of structure in use. This type of design prevents loss of life but does not limit damages or maintain functionality. As a newly developed method, resilience-based design (RBD) aims to maintain functionality of buildings and provide liveable conditions after strong ground movement. In this paper, the seismic performance of plain and strengthened RC frames (an eight-story and two low-rise) is evaluated. In order to evaluate earthquake performance of the frames, the performance points of the frames are calculated by the capacity spectrum method (CSM) of ATC-40. This method estimates earthquake-induced deformation of an inelastic system using a reduced response spectrum. Finally, the seismic performances of the frames are evaluated and the results are compared with a resilience-based design criterion.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.417-422
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• 2004

It is the challenging task to predict seismic demand for structural design. In current seismic design provisions such as UBC, NEHRP, ATC 3-06, the seismic demand is calculated using the response spectrum with response modification factor (R). This paper investigates variability of seismic demand according to selecting the earthquake ground motion groups. Different Earthquake sets used by Miranda, Riddell and Seed selected were used in this study. Earthquake sets selected by authors include 62 sets of near field ground motion and 19 sets one pulse ground motion. Linear Elastic Response Spectrum (LERS), the variation of performance points of calculated by Capacity Spectrum Method (CSM) were considered with respect to the different sets of earthquake ground motions.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.6
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• pp.17-24
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• 2003

The main objective of this paper is to evaluate the control performance of a coulomb friction damper(CFD) for controlling the inelastic behavior of seismically excited structures, The seismic performances of various buildings are evaluated using capacity spectrum method(CSM), and the additional dampings are calculated If the evaluated performance levels of the buildings are below the target level. Maximum friction force of the CFD to achieve additional damping is provided using the concept of equivalent viscous damping, Numerical simulations for single degree of freedom(SDOF) systems with various structural periods and post yield stiffness ratios demonstrate the effectiveness of the proposed procedure.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.4
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• pp.175-184
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• 2006

Two methods of the nonlinear static pushover analysis have been presented for the performance-based seismic design and evaluation of MDOF continuous bridges. Guidelines for buildings presented in FEMA-273 applying the Displacement Coefficient Method (DCM) and in ATC applying the Capacity Spectrum Method(CSM) have been modified for MDOF bridges. Two methods are compared with the time- history analysis. The lateral load distribution pattern for seismic loads has been examined in the static pushover analysis. The force-based fiber frame finite element has been implemented in the modeling of reinforced concrete piers.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.2
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• pp.75-84
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• 2003

Most structures are expected to deform beyond the limit of linearly elastic behavior when subjected to strong ground motion. Seismic evaluation of structure requires an estimation of the structural performance in terms of displacement demand imposed by earthquakes on the structure. The nonlinear response history analysis(NRHA) among various nonlinear analysis methods is the most accurate to compute seismic performance of structures, but it is time-consuming and necessitate more efforts. The nonlinear approximate methods, which is more practical and reliable tools for predicting seismic behavior of structures, are extensively studied. Among them, the capacity spectrum method(CSM) is conceptually simple, but the iterative procedure is time-consuming and may sometimes lead to no solution or multiple solutions. This paper considers a nonlinear direct spectrum method(NDSM) to evaluate seismic performance of mixed building structures without iterative computations, given dynamic property T from stiffness skeleton curve and nonlinear pseudo acceleration $A_{y}$/g and/or ductility ratio $\mu$ from response spectrum. The nonlinear response history analysis has been performed and analyzed with various earthquakes for estimation of reliability and practicality of NDSM with mixed building structures.