Seismic Behavior Evaluation of Semi-Rigid Steel Frames with EEP Connections under the near-Fault Earthquakes

2012 ◽  
Vol 174-177 ◽  
pp. 561-565
Author(s):  
Miaad Najdian ◽  
Mohsen Izadinia

Pulse shape motions and huge amount of energy applied in short duration by the near fault earthquake, cause brittle fracture in welded connections, which is widely observed in Kobe 1995 and Northridge 1994 earthquakes. Rigid connections, which are generally welded due to lack of ductility, have low energy absorption capability. On the other hand, Semi-rigid connections have a ductile behavior and have a good ability to absorb energy. The purpose of this paper is analysis and compares the behaviors of “rigid” and “EEP semi-rigid” connections in cases of “four bolt extended”, “eight bolt extended stiffened” and “eight bolt, four bolts wide, extended stiffened” under the near fault earthquakes with nonlinear time history analysis by perform 3D software. The results shown that the steel frame with “four bolt extended” semi-rigid connections have appropriate performance compared to the other frames.

2012 ◽  
Vol 166-169 ◽  
pp. 2083-2087
Author(s):  
Miaad Najdian ◽  
Mohsen Izadinia

Movements of pulse shape and the high energy applied in short duration by the near fault earthquake, causes brittle fracture in rigid connections that during the Northridge 1994 and Kobe 1995 earthquakes was frequently seen. Rigid connections, which are generally welded due to lack of ductility, have low energy absorption capability. On the other hand semi-rigid connections have a ductile behavior and have a good ability to absorb energy. The purpose of this paper is analysis and compares the behaviors of “rigid” and “TSW semi-rigid” connections under the near fault earthquakes with nonlinear time history analysis by perform 3D software.


Author(s):  
Seyed Kazem Sadat Shokouhi ◽  
Azam Dolatshah ◽  
Hamid Reza Vosoughifar ◽  
Yousef Rahnavard

Experiences of the previous earthquakes such as Bam, Northridge etc demonstrate that lifelines have no proper performance due to Near-Fault (NF) earthquakes. Hence, this research evaluates the influence of viscous dampers on the better performance of the water pipelines subjected to NF earthquakes. For this purpose, the water pipelines network of a zone in Tehran city was selected as a case study. The pipeline network was modeled using Finite Element Analysis (FEA), and nonlinear time-history analysis was undertaken via seismic scaled records of NF earthquakes. The obtained results indicated the critical points of network which were failed due to seismic waves. As a solution, viscous dampers were employed for improving the behavior of the mentioned points. The obtained results demonstrate that the failure points were retrofitted efficiently by viscous dampers.


2020 ◽  
Vol 47 (4) ◽  
pp. 470-486
Author(s):  
Alireza Esfahanian ◽  
Ali Akbar Aghakouchak

Nonlinear time-history analysis conducted as part of a performance-based seismic design approach often require that the ground motion records are selected and then scaled to a specified level of seismic intensity. In such analyses, besides an adequate structural model, a set of acceleration time-series is needed as the most realistic representation of the seismic action. In this paper, the effects of scaling procedure on seismic demands of steel frames are investigated. To this, two special steel moment-resisting frames with considerable higher mode effects, and two sets of ground motions, including near-fault and far-fault motions are considered. Moreover, three scaling procedures are introduced for performing nonlinear dynamic time-history analysis of structures. Among different demands, lateral roof displacement and interstory drift are selected as seismic demands. The height-wise distribution of demands shows that the inelastic seismic demands of the near-fault pulse-like ground motions differ considerably from those of far-fault ones. These results show that the story drifts are mostly larger for far-fault motions in the upper story levels in comparison to near-fault records and in the lower floors, the reverse is true. Thus, the scaling procedures directly affect the results of seismic demands and choosing different methods would result in varying responses. Moreover, a low-cost and fairly effective procedure is proposed to estimate the target displacement demands of buildings from response-spectrum analyses, considering near-fault effects. The precision of this method is verified by nonlinear time-history analysis results, as the benchmark solution, and acceptable improvements have been achieved.


2018 ◽  
Vol 20 (1) ◽  
pp. 35
Author(s):  
Pamuda Pudjisuryadi ◽  
Benjamin Lumantarna ◽  
Ryan Setiawan ◽  
Christian Handoko

The recent seismic code SNI 1726-2012 is significantly different compared to the older code SNI 1726-2002. The seismic hazard map was significantly changed and the level of maximum considered earthquake was significantly increased. Therefore, buildings designed according to outdated code may not resist the higher demand required by newer code. In this study, seismic performance of Hotel X in Kupang, Indonesia which was designed based on SNI-1726-2002 is investigated. The structure was analyzed using Nonlinear Time History Analysis. The seismic load used was a spectrum consistent ground acceleration generated from El-Centro 18 May 1940 North-South component in accordance to SNI 1726-2012. The results show that Hotel X can resist maximum considered earthquake required by SNI 1726-2012. The maximum drift ratio is 0.81% which is lower than the limit set by FEMA 356-2000 (2%). Plastic hinge damage level is also lower than the allowance in ACMC 2001.


2009 ◽  
Vol 25 (3) ◽  
pp. 583-605 ◽  
Author(s):  
Wei Chiang Pang ◽  
David V. Rosowsky

This paper presents a direct displacement design (DDD) procedure that can be used for seismic design of multistory wood-framed structures. The proposed procedure is applicable to any pure shear deforming system. The design procedure is a promising design tool for performance-based seismic design since it allows consideration of multiple performance objectives (e.g., damage limitation, safety requirements) without requiring the engineer to perform a complex finite element or nonlinear time-history analysis of the complete structure. A simple procedure based on normalized modal analysis is used to convert the code-specified acceleration response spectrum into a set of interstory drift spectra. These spectra can be used to determine the minimum stiffness required for each floor based on the drift limit requirements. Specific shear walls can then be directly selected from a database of backbone curves. The procedure is illustrated on the design of two three-story ATC-63 archetype buildings, and the results are validated using nonlinear time-history analysis.


2020 ◽  
Vol 36 (2) ◽  
pp. 806-831 ◽  
Author(s):  
Xinzheng Lu ◽  
Frank McKenna ◽  
Qingle Cheng ◽  
Zhen Xu ◽  
Xiang Zeng ◽  
...  

Regional seismic damage simulation of buildings provides decision-makers with important information for earthquake disaster prevention and mitigation. Utilizing nonlinear time history analysis using multiple-degree-of-freedom (MDOF) models for buildings, and the next-generation performance-based earthquake engineering, an open-source general-purpose scientific workflow for seismic damage simulation and loss prediction of urban buildings (referred to as SimCenter Workflow) is presented in this study. To introduce the SimCenter Workflow process in detail and demonstrate its advantages, a seismic damage simulation and loss prediction for 1.8 million buildings in the San Francisco Bay Area were performed using the SimCenter Workflow. The open nature and modularization of the SimCenter Workflow facilitate its extensibility and make it practical for researchers to apply to seismic damage simulations in other regions.


2011 ◽  
Vol 243-249 ◽  
pp. 3889-3892 ◽  
Author(s):  
Tian Li Wang ◽  
Qing Ning Li ◽  
Hai Jun Yin

In order to analyze seismic response of the curved ramp bridge, this paper selected a single curved ramp bridge in a multilevel junction system as its research object. Considering the piers, beams, bearings and expansion joints simulation, it respectively built the calculating models for a curved ramp bridge and a corresponding linear one. Using nonlinear time history analysis, the paper contrasts seismic response of the curved ramp bridge with that of the linear one in several different seismic inputs. Finally the seismic response characteristic of a curved ramp bridge is put forward.


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