Seismic response factors of reinforced concrete pedestal in elevated water tanks

2015 ◽  
Vol 87 ◽  
pp. 32-46 ◽  
Author(s):  
R. Ghateh ◽  
M.R. Kianoush ◽  
W. Pogorzelski
Keyword(s):  
Reinforced Concrete ◽  
Seismic Response ◽  
Response Factors ◽  
Elevated Water ◽  
Water Tanks

scholarly journals Innovative Experimentation on Hollow Cylindrical Shells of Reinforced Concrete under Axial Compressive Load

2019 ◽  
Vol 8 (3) ◽  
pp. 2044-2049
Keyword(s):  
Reinforced Concrete ◽  
Axial Compression ◽  
Structural Model ◽  
Testing Machine ◽  
Compressive Load ◽  
Water Tank ◽  
Critical Question ◽  
Axial Compressive Load ◽  
Elevated Water ◽  
Water Tanks

Reinforced concrete elevated water tanks supported on shaft type staging system are popularly constructed now a days for storage of water for water supply schemes. If slip form is used for casting of the shaft staging, the water towers generally require lesser time for construction. Elevated water tanks are top heavy structure especially in the tank full condition. It is often a critical question in structural design that what should be the proper structural model adopted for design of such class of structure. Should the shaft be designed as a hollow cylindrical column subjected to axial compression or is it essentially a R.C. cylindrical shell subjected to membrane forces under axial compression. To better understand it is proposed to cast such R.C. shells and after water curing for 28 days shall be subjected to axial compressive load in a compressive strength testing machine. The failure pattern of the shells shall be observed critically to get a proper understanding of behavior of such R.C shaft supported elevated water tank structures.

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.

Non-Linear Time History Analysis of an Elevated Water Tank

2021 ◽  
Vol 9 (VI) ◽  
pp. 4327-4334
Author(s):  
Mr. Rohit Kiran Chaudhari
Keyword(s):  
Reinforced Concrete ◽  
Seismic Analysis ◽  
Linear Time ◽  
Time History ◽  
Seismic Energy ◽  
Soil Condition ◽  
Mode Shapes ◽  
Water Tank ◽  
Elevated Water ◽  
Water Tanks

It was discovered that reinforced concrete elevated water tanks with frame staging outperformed reinforced concrete elevated water tanks with shaft staging in terms of seismic resistance. These can be due to the frame staging's seismic energy absorption capability. As a result, the primary goal of this research is to better understand the seismic behavior and performance characteristics of elevated water tanks with frame staging. Furthermore, when compared to other shapes, circular tanks have the smallest surface area for a given tank size. As a result, the amount of material needed for a circular water tank is less than for other shapes. As a result, a circular water tank was chosen, and seismic analysis of elevated RC circular water tanks was carried out according to IITK-GSDMA guidelines, with the behavior of the water tank analysed for various parameters such as zone factor, soil condition, and different staging heights. SAP 2000 was used to determine the structure's modal characteristics (mode shapes and modal participation mass ratio).

Seismic Response of Isolated Elevated Water Tanks

1999 ◽  
Vol 125 (9) ◽  
pp. 965-976 ◽  
Author(s):  
Harry W. Shenton ◽  
Francis P. Hampton
Keyword(s):  
Seismic Response ◽  
Elevated Water ◽  
Water Tanks

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.

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