A Method for the Structural Analysis and Design of Arched Reinforced Masonry and/or Concrete Structures

Abstract

Extraordinary architectural examples of shell structures have been built using reinforced masonry and concrete. The current sparse use of this construction type can be attributed, among other reasons, to a lack of simple design methods, tools and criteria. Extended Limit Analysis of Reinforced Masonry (ELARM) is a new method for the structural analysis and design of reinforced concrete, reinforced masonry or reinforced composite (masonry and concrete) arched structures. It is implemented computationally to create a flexible design and analysis tool, able to provide immediate graphical and intuitive results. The method is based on limit analysis but takes into account the material’s limited compressive strength and the vault’s cross-sectional bending capacity provided by the reinforcement as an equivalent increase of the thickness. The plastic theorems are then applied considering the new virtual boundaries of the vault’s intrados and extrados. ELARM is validated through the comparison of its predictions with the results of load tests on two full-scale composite barrel vaults. The vaults feature a structural system composed of a two-layered tile vault as an integrated formwork for a reinforced concrete layer. They were tested under vertical loading up to failure. Both the vertical and horizontal displacements of the vaults were monitored during the tests. The characterisation of the materials composing the vaults was also carried out to introduce the measured material properties and strengths in the equilibrium equations for the computation of the new virtual thickness. This paper presents the new structural analysis and design method, its experimental validation and some practical design examples to show the potential of the tool. It offers an intuitive process of design in which shape can be adapted and optimised, also having the material properties and thickness, loads and reinforcement quantity and placement as variable parameters. The presented examples include reinforcement optimisation and form-finding procedures and the analysis of a non-compression-dominated structure.

Full document

References

[1] López López, D., Van Mele, T. and Block, P. Dieste, González Zuleta and Sánchez del Río: Three approaches to reinforced-brick shell structures. 10th International Conference on Structural Analysis of Historical Constructions (ed. Van Balen, K., & Verstrynge, E.). London: Taylor & Francis Group (2016).

[2] Meyer C, Sheer M. Do Concrete Shells Deserve Another Look? Concrete International, Oct. 2005: 43-50.

[3] Tang G. An Overview of Historical and Contemporary Concrete Shells, their Construction and Factors in their General Disappearance. International Journal of Space Structures 2015; 30(1).

[4] López López, D., Roca, P., Liew, A., Van Mele, T., & Block, P. (2019b). Tile vaults as integrated formwork for reinforced concrete: Construction, experimental testing and a method for the design and analysis of two-dimensional structures. Engineering Structures, 188, 233-248.

[5] López López D, Domènech M, Palumbo M. “Brick-topia”, the thin-tile vaulted pavilion. Case Studies in Structural Engineering 2014; 2: 33-40.

[6] López López D, Van Mele T, Block P. Tile vaulting in the 21st century. Informes de la Construcción 2016; 68(544): e162, DOI: 10.3989/ic.15.169.m15.

[7] López López, D., Van Mele, T., & Block, P. (2019a). The combination of tile vaults with reinforcement and concrete. International Journal of Architectural Heritage, 13:6, 782- 798. DOI: 10.1080/15583058.2018.1476606.

[8] Roca P, López-Almansa F, Miquel J, Hanganu A. Limit analysis of reinforced masonry vaults. Engineering Structures 2007; 29: 431-9.

[9] Heyman J. The stone skeleton. International Journal of Solids and Structures 1966; 2: 249– 79.