scholarly journals Rational Evaluation of Seismic Response Modification Factor of Steel Moment Frame Based on Available Connection Rotation Capacity

2007 ◽  
Vol 11 (2) ◽  
pp. 11-17
2021 ◽  
Author(s):  
Razmyar Ghateh

Elevated water tanks are employed in water distribution facilities in order to provide storage and necessary pressure in water network systems. These structures have demonstrated poor seismic performance in the past earthquakes. In this study, a finite element method is employed for investigating the nonlinear seismic response of reinforced concrete (RC) pedestal in elevated water tanks. A combination of the most commonly constructed tank sizes and pedestal heights in industry are developed and investigated. Pushover analysis is performed in order to construct the pushover curves, establish the overstrength and ductility factor, and evaluate the effect of various parameters such as fundamental period and tank size on the seismic response factors of elevated water tanks. Furthermore, a probabilistic method is implemented to verify the seismic performance and response modification factor of elevated water tanks. The effect of wall openings in the seismic response characteristics of elevated water tanks is investigated as well. Finally, the effect of axial compression on shear strength of RC pedestals is evaluated and compared to nominal shear strength from current guideline and standards. The results of the study show that the tank size, pedestal height, fundamental period, and pedestal height to diameter ratio, could significantly affect the overstrength and ductility factor of RC pedestals. The nonlinear dynamic analysis results reveal that under the maximum considered earthquake (MCE) intensity, light and medium size tank models do not experience significant damages. However, heavy tank size models experience more damage in comparison with light and medium tank sizes. This study shows that the current code response modification factor values are appropriate for light and medium tank sizes; however they need to be modified for heavy tank sizes. The results of this study also reveal that if the pedestal wall openings are designed based on current design guidelines, then nearly identical nonlinear seismic response behaviour is expected from the pedestals with and without openings. Finally, it is shown that the pedestal maximum shear strength calculated by finite element method for the full tank state is higher than the nominal shear strength determined based on the current design guidelines compared to the nominal shear strength from current guideline and standards.


2019 ◽  
Vol 181 ◽  
pp. 427-436 ◽  
Author(s):  
Fatemeh Aliakbari ◽  
Hashem Shariatmadar

2021 ◽  
Vol 8 (1) ◽  
pp. 1923363
Author(s):  
Manar M. Hussein ◽  
Manar Gamal ◽  
Walid A. Attia

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
M. Sadeghpour ◽  
V. R. Kalatjari ◽  
H. Pahlavan

Abstract The purpose of the present study was to investigate the effect of the geometric arrangement of the trusses on the response modification factor of the special truss moment frame. For this purpose, six different geometric arrangements for the three types of trusses (Vierendeel, multiple Vierendeel panels, and X-diagonals) were considered. The results were obtained based on non-linear static analysis of two- and three-span frames for 4- and 8-story structures with the given geometric arrangements. According to the results obtained, different truss arrangements can affect the response modification factor by about 4 to 10%. Additionally, using multiple Vierendeel panels and the X-diagonals can increase the response modification factor by 1.06 and 1.74 times, respectively. Article Highlights Different truss arrangements do not have a significant effect on the coefficient of behavior. The addition of several Vierendeel panels does not have much effect on the behavior of these structures. Adding cross diameters almost doubles the coefficient of behavior and significantly improves the performance of the structure.


2021 ◽  
Author(s):  
Razmyar Ghateh

Elevated water tanks are employed in water distribution facilities in order to provide storage and necessary pressure in water network systems. These structures have demonstrated poor seismic performance in the past earthquakes. In this study, a finite element method is employed for investigating the nonlinear seismic response of reinforced concrete (RC) pedestal in elevated water tanks. A combination of the most commonly constructed tank sizes and pedestal heights in industry are developed and investigated. Pushover analysis is performed in order to construct the pushover curves, establish the overstrength and ductility factor, and evaluate the effect of various parameters such as fundamental period and tank size on the seismic response factors of elevated water tanks. Furthermore, a probabilistic method is implemented to verify the seismic performance and response modification factor of elevated water tanks. The effect of wall openings in the seismic response characteristics of elevated water tanks is investigated as well. Finally, the effect of axial compression on shear strength of RC pedestals is evaluated and compared to nominal shear strength from current guideline and standards. The results of the study show that the tank size, pedestal height, fundamental period, and pedestal height to diameter ratio, could significantly affect the overstrength and ductility factor of RC pedestals. The nonlinear dynamic analysis results reveal that under the maximum considered earthquake (MCE) intensity, light and medium size tank models do not experience significant damages. However, heavy tank size models experience more damage in comparison with light and medium tank sizes. This study shows that the current code response modification factor values are appropriate for light and medium tank sizes; however they need to be modified for heavy tank sizes. The results of this study also reveal that if the pedestal wall openings are designed based on current design guidelines, then nearly identical nonlinear seismic response behaviour is expected from the pedestals with and without openings. Finally, it is shown that the pedestal maximum shear strength calculated by finite element method for the full tank state is higher than the nominal shear strength determined based on the current design guidelines compared to the nominal shear strength from current guideline and standards.


2011 ◽  
Vol 71-78 ◽  
pp. 1605-1608 ◽  
Author(s):  
Yong Kang Shen

Seismic response modification factor (R) and displacement amplification factor (Cd) are very important parameters to compute seismic force and to verify elasto-plasticity deformation in advanced seismic design. According to the present China Code for Seismic Design of Buildings,15 eccentrically braced steel frames are designed. R & Cd of 15 samples are computed by the Capacity Spectrum Method (CSM).Some correlative factors are analyzed and some reference is presented to the seismic design of these structures.


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