Dr Yuri Totoev

© 2019, © 2019 Engineers Australia. When considering models for seismic assessment and retrofit design, designers need to account for any changes in the structural ductility factor and performance factor between an original unreinforced masonry structure and one which has been subsequently retrofitted. There are enough data available in the literature and the standards to suggest ductility and performance factors for existing unreinforced masonry walls or buildings. However, there is a lack of information regarding the above-mentioned factors for retrofitted structures or walls. Retrofitting unreinforced masonry buildings can improve the behaviour factors, displacement capacity, stiffness and performance of the structure. Retrofit strategies are aimed at improving the performance of the structure locally by considering the weak or brittle elements, and/or to improve the global behaviour of the building by focusing on the connections of the elements. In the present paper, the different retrofitting techniques for unreinforced masonry walls and unreinforced masonry buildings are considered. The structural factors for retrofitted walls and structures are calculated using experimental data extracted from the literature and are compared, together with a discussion, to the pre-retrofitting factors available in the literature and different standards. The implications for the relevant standards regarding the performance of retrofitted masonry structures are also discussed.

© 2018 The International Masonry Society (IMS). Mortar-less Semi-Interlocking Masonry (SIM) has been designed in the Centre for Infrastructure Performance and Reliability at The University of Newcastle for seismically vulnerable regions as an alternative to traditional masonry panels. This innovative masonry building system consists of mortar-less masonry panels with multiple sliding bed joints made of semi-interlocking units capable of relative sliding in-plane of a panel but interlocked against relative out-of-plane movement. These new panels are suitable for both infill and confined masonry. The major objective of developing this new masonry system is to improve the earthquake performance of the framed structure by increasing the displacement ductility and the energy dissipation capacity of infill panels. An experimental program is developed to evaluate displacement ductility of the infill panels under large displacement. It consists of a special steel testing frame with pin connections, which allows the panels distortion up to 6% of storey height. Digital Image Correlation (DIC) technique is used to monitor the displacement and crack behaviour of the panel. This paper reports the results of this testing program with mechanically interlocking units in terms of force-displacement relationship as well as energy dissipation capacity of the system.

© 2018 The International Masonry Society (IMS). A new masonry system is being developed in the Centre for Infrastructure Performance and Reliability at The University of Newcastle. The Semi-Interlocking Masonry (SIM) system allows relative sliding of brick courses in-plane and prevents out-of-plane relative displacement of bricks. Hence, SIM has significant friction forces induced on sliding joints during earthquakes and can be used as an energy dissipation device in framed structures with masonry panels. The applicability of (SIM) as an earthquake resistant infill masonry system has been demonstrated and proven experimentally. However, it was not considered for confined masonry, which is very common in many seismic regions. Traditional confined masonry uses unreinforced masonry (URM) walls. The structural behaviour of this system shows better performance during earthquakes compared to unframed URM walls. It also seems to be cost effective as it requires less reinforcement and concrete than RC frame with masonry infill; however, it has lower strength and ductility compared to infill systems. The aim of this paper is to investigate the application of semi interlocking masonry walls in a confined masonry system. A confined SIM wall is designed and an analytical model for its in-plane shear capacity is proposed. The shear capacity of confined SIM walls is compared to the capacity of confined conventional URM walls.

© 2018 The International Masonry Society (IMS). The Semi-Interlocking Masonry (SIM) system has developed in Masonry Research Group at the University of Newcastle, Australia. The main purpose of this system is to enhance the seismic resistance of framed structures with masonry panels. In this system, SIM panels dissipate energy through the sliding friction on lip joints between rows of SIM units during earthquake excitation. A number of testing programs have been carried out to evaluate the in-plane capacity of different framed SIM panels. However, the out-of-plane behaviour of SIM has received less attention. The main objective of this study is to investigate the thrust force induced in SIM during its out-of-plane deflection. The relationship between the thrust force and the out-of-plane deflection was investigated experimentally for horizontal and vertical arching. Three types of bricks were used in tests: topological SIM, mechanical SIM, and traditional bricks without any interlocking. The dimensions of all units were 220 × 110 × 76 mm (length, width, and height). The lateral load was applied by hydraulic jack, the displacement and the thrust force were recorded by Linear Variable Differential Transformer (LVTD) and Load Cell respectively. This paper presents results of eighteen arching tests: six tests with topological interlocking, six tests with mechanically interlocking units, and six tests with ordinary bricks.