New energy based approach to predict seismic demands of steel moment resisting frames subjected to near-fault ground motions

2014 ◽  
Vol 72 ◽  
pp. 182-192 ◽  
Author(s):  
Seyyed Amin Enderami ◽  
Seyed Bahram Beheshti-Aval ◽  
Mohamad Ala Saadeghvaziri
Author(s):  
Ehsan Khojastehfar ◽  
Farzad Mirzaei Aminian ◽  
Hamid Ghanbari

Characteristics of earthquake strong ground motions play an important role in the calculation of seismic-induced risk imposed on the structures. Distinguished features exist in movements recorded near seismic sources, as a result of a substantial amount of energy in a short period of record arrival time. In this article, seismic risk analysis of concrete moment-resisting frames due to near-fault strong ground motion is calculated and compared with that of caused by far-field strong ground motions. To achieve this goal, three moment-resisting frames with 4, 6, and 10 stories were designed based on international seismic design code. These frames are modeled applying modified Ibarra–Krawinkler moment–rotation nonlinear model in which strength and stiffness deterioration are involved. Seismic risk analysis of the frames is implemented using the Pacific Earthquake Engineering Research Center approach. Through this approach, probabilistic seismic hazard, probabilistic structural demand, probabilistic structural damage, and probabilistic loss curves are combined. Mean annual frequency of exceedance of seismic-induced losses presents probabilistic seismic risk of the sampled frames. According to the achieved results, the four-story frame (representative of low-rise frames) is more prone to be affected by near-fault strong ground motions in view of calculated seismic-induced risks.


2020 ◽  
pp. 875529302097120
Author(s):  
Xingquan Guan M.EERI ◽  
Henry Burton M.EERI ◽  
Mehrdad Shokrabadi

A number of simplified methodologies have been developed and used to estimate seismic drift demands in buildings. However, none of them have been systematically tested against a large number of buildings subjected to a diverse set of ground motions. This is partly attributed to the lack of existing databases of building designs, nonlinear structural models, and simulated seismic responses. This article introduces the development of a comprehensive database, which includes 621 special steel moment-resisting frames designed in accordance with modern codes and standards and their corresponding nonlinear structural models and seismic responses (i.e. peak story drifts, peak floor accelerations, and residual story drifts). The seismic responses for a subgroup of 100 steel moment-resisting frames subjected to three groups of site-specific ground motions (with 40 records each), at the service-level, design-based, and maximum considered earthquakes, are also included. The database has been utilized by the authors (in a separate study) to evaluate the performance of existing methods and develop data-driven and hybrid (combination of mechanics-based and data-driven) models for estimating seismic structural drift demands. The database can also be utilized in the development and implementation of a performance-based analytics-driven seismic design methodology.


2016 ◽  
Vol 847 ◽  
pp. 222-232
Author(s):  
Bora Aksar ◽  
Selcuk Dogru ◽  
Bulent Akbas ◽  
Jay Shen ◽  
Onur Seker ◽  
...  

This study focuses on exploring the seismic axial loads for columns in steel moment resisting frames (SMRFs) under strong ground motions. For this purpose, the increases in axial loads are investigated at the maximum lateral load level and the corresponding lateral displacement. The results are presented in terms of maximum amplification factors (Ω0) of all frame columns under the selected ground motions and axial load-moment levels in columns. four typical steel moment resisting frames representing typical low, medium and high rise steel buildings are designed based on the seismic design requirement in ASCE 7-10 and AISC 341-10 . An ensemble of ground motions range from moderate to severe are selected to identify the seismic response of each frames. Two sets of ground motions corresponding to 10% and 2% probability of exceedance are used in nonlinear dynamic time history analyses.


2014 ◽  
Vol 8 (1) ◽  
pp. 310-323 ◽  
Author(s):  
Massimiliano Ferraioli ◽  
Alberto M. Avossa ◽  
Angelo Lavino ◽  
Alberto Mandara

The reliability of advanced nonlinear static procedures to estimate deformation demands of steel momentresisting frames under seismic loads is investigated. The advantages of refined adaptive and multimodal pushover procedures over conventional methods based on invariant lateral load patterns are evaluated. In particular, their computational attractiveness and capability of providing satisfactory predictions of seismic demands in comparison with those obtained by conventional force-based methods are examined. The results obtained by the static advanced methods, used in the form of different variants of the original Capacity Spectrum Method and Modal Pushover Analysis, are compared with the results of nonlinear response history analysis. Both effectiveness and accuracy of these approximated methods are verified through an extensive comparative study involving both regular and irregular steel moment resisting frames subjected to different acceleration records.


2017 ◽  
Vol 11 (05) ◽  
pp. 1750016 ◽  
Author(s):  
Reza Vahdani ◽  
Mohsen Gerami ◽  
Morteza Razi

This paper investigates the seismic vulnerability of steel moment-resisting frames (SMRFs) based on plasticity development in structural components. Pushover analyses with three different lateral load patterns are performed to identify the location of plastic hinges at the collapse state and IDA analysis is employed to find the seismic intensities causing the formation of the specified hinges. An ensemble of 30 near-fault pulse-like motions classified into three groups of short, medium and long period motions and ten ordinary ground motions are used for seismic loading on five sample frames with 3 to 15 stories. Employing this method, the interstory drift ratio coincident to the seismic collapse is evaluated. Then, the critical pulse period producing the most damage to the structures is estimated. Finally, fragility curves are developed for near- and far-fault excitations. The results indicate that maximum interstory drift ratio at the collapse state of the frames ranges from 1.5% to 10%. It is also found that the ratio of critical pulse period to natural period of SMRF structures is between 2.3 and 2.9. Moreover, the fragility analysis reveals that collapse intensity equivalent to 10% of exceedence for near-fault motions is 70% to 85% less than far-fault records.


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