Time-dependent and thermal behaviour of spherical shallow concrete domes

Abstract

This paper investigates the long-term and thermal behaviour of spherical shallow, thin walled concrete domes. Although these structures are vulnerable to creep, shrinkage and thermal effects, a thorough understanding of their time-dependent behaviour has hitherto not been fully established. The paper aims to provide outcomes and insight to enhance the effective design and safe use of shallow concrete domes, and a theoretical model, which accounts for the membrane and bending behaviour, as well as for creep, shrinkage and thermal effects, is developed for this purpose. The analytical model uses variational principles, equilibrium requirements, and the time-dependent constitutive relations of the concrete material. The equilibrium equations derived from this boundary value problem are solved via the so-called multiple shooting numerical method, which enables the incorporation of the variable thickness of the shell, its different boundary conditions, and various types of axisymmetric loadings in the solution. A numerical example and a parametric study, which highlight the capabilities of the proposed theoretical model and which provide some insight into the long-term and thermal behaviour of shallow concrete domes, are presented. The results show that long-term and thermal effects play important roles in the behaviour and structural safety of shallow, thin-walled concrete domes, and so these effects need to be fully understood and quantifiable.