A Comprehensive Analysis Structure for the Design of Masonry Arches

Background: Structural masonry framing has the potential to be an advantageous design technique for new constructions. The realization of this potential requires both design modernizations and accessible analysis methodologies. The focus and understanding of masonry frames have been directed towards the management and preservation of cultural heritage. This has resulted in an assessment approach to the analysis and duality of the term “masonry” to describe both a material and a method of construction. Objectives: The objective of this work is to differentiate masonry as a method and masonry as a material and to use this differentiation to present a comprehensive method-based analysis structure for masonry arches that is formulated around the need to control and optimize the system. Methods: This work presents an analysis approach that defines and utilizes kinematic equilibrium to establish determinant systems. This is achieved through the inclusion of a loading variable to a defined mechanical condition of the arch. The solution to the equilibrium equation sets is evaluated for admissibility through the examination of the thrust line and arch geometry. The simplified analysis is formulated into a simple software structure, a first-order assessment strategy, a characterization technique to link experiment and theory, and carried to dynamic modeling. Results: The results of the approach are the foundation and blueprint for a comprehensive, efficient, and adaptable structural analysis platform designed for the structural analysis of masonry frames. Conclusion: The developed analysis approach and supporting applications cover the base requirements for promoting the application of masonry frames for new constructions.

Preliminary Observations on Historical Castle Trakošćan (Croatia) Performance under Recent ML ≥ 5.5 Earthquakes

Trakošćan Castle, built on a rocky peak in the late 13th century, is a cultural heritage site protected as a historical entity by the Republic of Croatia. The Castle is constructed as a highly irregular masonry structure with timber or shallow masonry arches, vaults or dome floors. It was substantially renewed, upgraded and partially retrofitted from the 16th century until the year 2000. The M5.5 (VIII EMS) and M6.2 (VIII-IX EMS) earthquakes, which struck the city of Zagreb on 22 March 2020 and the Pokupsko-Petrinja area on 29 December 2020, strongly shook the Castle’s structure. Earthquake damage was observed and assessed by visual inspection accompanied by ambient vibration measurements. The slight cracks that appeared on masonry arches were found to be critically positioned, and can likely lead to the arches’ collapse if their spreading is not prevented. Ambient vibration measurements, which were compared to pre-earthquake ones, revealed the decrease in the fundamental frequencies of the Castle’s central tower unit and the second floor, thus possibly indicating the loss of structural stiffness as a consequence of the earthquake damage.

ADAPTATION OF THE TSAI-HILL CRITERION FOR THE STUDY OF THE BEHAVIOR OF MASONRY ARCHES ADAPTATION OF THE THAI-HILL CRITERION FOR THE STUDY OF THE BEHAVIOR OF MASONRY ARCHES: COMPARISON BETWEEN MASOMODEL, EXPANDED MICROMODEL AND DETAILED MICROMODEL

Since the beginning of the structural analysis of masonry structures, it has been sought to know their behavior taking into account the influence of the different elements that make it up, evolving the structural analysis of masonry arches to analyze the fracto-mechanical behavior of the masonry. This article presents the adaptation of the Tsai-Hill failure criterion for orthotropic materials, for the study of masonry arches. Implementing the adaptation in a VUSFLD subroutine of ABAQUS in Fortran programming language. This subroutine has been validated in view of the failure of the mortar, and the effect of considering mortar in the analysis of a masonry arch. The subroutine implemented in a masomodel allows observing its contribution to the bearing capacity of an arch. Key Words: Masonry Arch; ABAQUS subroutine; failure Criterion; Mortar; structural analysis; Tsai-Hill failure criterion