DESIGN APPROACH FOR RC PANELS (SHELLS) IN INDUSTRIAL FACILITIES BASED ON ACI CODES

Reinforced Concrete (RC) wall and shell type structures such as those used in safety-related nuclear facilities, offshore structures, and other industrial facilities are designed following the Element-by-Element Level (ELD) deign method. In such structures, which are over labyrinthine in plan, the RC walls can be extremely long and interconnected to several other walls. It is impossible to distinguish and design the walls as independent shear walls or units. Consequently, these structures are analyzed using 3D finite element models, and the demands obtained from such analyses are used to design the walls. While the demands are obtained on an element-by-element level, they can be averaged over finite lengths defined by a (two-dimensional, 2D) RC panel in order to account for the spread of yielding when ductile limit states govern behavior.

The design demands of RC panels are a combination of in-plane and out-of-plane forces/moments, which interact simultaneously. The ACI 349 and the ACI 318.2-19 codes, do not provide clear design guidance for RC panels, and for this reason, a new design approach consistent with the behavioral assumptions in these ACI codes are developed and proposed in this thesis. The results of this ACI-Panel-Based-Design-Approach (PACI) are verified using experimental results from twenty-one RC panel tests subjected to different combinations of in-plane and out-of-plane forces and moments as follows: (i) The PACI approach is used to calculate the required reinforcement areas for these specimens. (ii) Benchmarked numerical models are developed for the specimens with the PACI suggested reinforcement. (iii) Numerical models are analyzed for the same loading conditions and combinations as the tested specimens, and the calculated capacities are compared with those from the tests. The results of the PACI approach are also compared with those obtained using the more mechanistic “sandwich” model approach referenced in the Eurocode for RC shells (or panels). Finally, the use, safety, and efficiency of the PACI approach and Eurocode approach are illustrated by designing the critical wall panels of a nuclear structure with design demands published in the literature.