Seismic response modification factor for steel slit panel-frames

2019 ◽  
Vol 181 ◽  
pp. 427-436 ◽  
Author(s):  
Fatemeh Aliakbari ◽  
Hashem Shariatmadar
Keyword(s):  
Seismic Response ◽  
Response Modification Factor ◽  
Modification Factor

scholarly journals Nonlinear seismic response of reinforced concrete pedestals in elevated water tanks

2021 ◽  
Author(s):  
Razmyar Ghateh
Keyword(s):  
Shear Strength ◽  
Seismic Response ◽  
Design Guidelines ◽  
Current Guideline ◽  
Response Modification Factor ◽  
Nonlinear Seismic Response ◽  
Current Design ◽  
Modification Factor ◽  
Elevated Water ◽  
Water Tanks

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.

scholarly journals Seismic response modification factor for RC-frames with non-uniform dimensions

2021 ◽  
Vol 8 (1) ◽  
pp. 1923363
Author(s):  
Manar M. Hussein ◽  
Manar Gamal ◽  
Walid A. Attia
Keyword(s):  
Seismic Response ◽  
Response Modification Factor ◽  
Rc Frames ◽  
Modification Factor

scholarly journals Nonlinear seismic response of reinforced concrete pedestals in elevated water tanks

2021 ◽  
Author(s):  
Razmyar Ghateh
Keyword(s):  
Shear Strength ◽  
Seismic Response ◽  
Design Guidelines ◽  
Current Guideline ◽  
Response Modification Factor ◽  
Nonlinear Seismic Response ◽  
Current Design ◽  
Modification Factor ◽  
Elevated Water ◽  
Water Tanks

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.

Seismic Response Modification Factor of Eccentrically Brace Steel Frame

2011 ◽  
Vol 71-78 ◽  
pp. 1605-1608 ◽  
Author(s):  
Yong Kang Shen
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Amplification Factor ◽  
Steel Frames ◽  
Capacity Spectrum Method ◽  
Response Modification Factor ◽  
Capacity Spectrum ◽  
Seismic Force ◽  
Elasto Plasticity ◽  
Modification Factor

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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