Influence of the Behaviour Coefficient on the Damage Level of an RC Elevated Tank under Seismic Loading

Abstract

In Algeria, the seismic design of elevated concrete storage tanks is carried out in accordance with seismic standard, involving a behavior coefficient of the structure. This behaviour coefficient is used to determine the internal forces and to estimate the inelastic deformations undergone by the structure. For the elevated water tank, considered as reverse pendulum structure, this coefficient assumes a constant value (R=2) in the Algerian seismic code. Taking into account a single value, whatever the seismic zone, the site of implantation and the geometric characteristics of the structure, can lead to design errors leading to oversizing, hence an additional cost of the structure. Thus, faced with the need to design resistant structures while minimizing construction costs, it is important to precisely determine the value of this behaviour coefficient to introduce into the evaluation of the structure's response. In this research, the seismic performance of an RC elevated tank is analyzed, using a nonlinear approach based on the Pushover method, initially using the behavior coefficient prescribed by the Algerian seismic code, then secondly using the behavior coefficient approximated by a power-type law, taking into account the seismic zone, the type of soil, the height of the structure and the storage capacity. The results of this study highlight the influence of the value of the behavior coefficient on the seismic performance and the level of damage to an elevated tank.

Keywords

• Behavior coefficient
• Pushover method
• Nonlinear approach
• Elevated tank

References

1. ATC-40. (1996). Seismic evaluation and retrofit of concrete buildings (Volume 1). Applied Technology Council. Retrieved from https://www.atcouncil.org/pdfs/atc40toc.pdf
2. Desprez, C., Mazars, J., Kotronis, P., & Paultre, P. (2013). Damage model for FRP-confined concrete columns under cyclic loading. Engineering Structures, 48, 519–531.
3. DTR/B-C 2–48. (2003) .National seismic code for building design and construction (R.P.A 99/ version 2003).
4. Ider, O. (2023). Evaluation of the global behavior coefficient R for elevated tanks. (Doctoral dissertation). Mouloud Mammeri University of Tizi-Ouzou. Algeria.