• Earthquakes and Structures
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• v.13 no.1
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• pp.29-38
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• 2017

Stone masonry is one of the oldest construction types due to the natural and free availability of stones and the relatively easy construction. Since stone masonry is brittle, it is also very vulnerable and in the case of earthquakes damage, collapses and causalities are very likely to occur, as it has been seen during the last Italian earthquake in Amatrice in 2016. In the recent years, some researchers have performed experimental tests to improve the knowledge of the behaviour of stone masonry. Concurrently, there is the need to reproduce the seismic behaviour of these structures by numerical approaches, also in consideration of the high cost of experimental tests. In this work, an alternative simplified procedure to numerically reproduce the diagonal compression and shear compression tests on a rubble stone masonry is proposed within the finite element method. The proposed procedure represents the stone units as rigid bodies and the mortar as a plastic material with compression and tension inelastic behaviour calibrated based on parametric studies. The validation of the proposed model was verified by comparison with experimental data. The advantage of this simplified methodology is the use of a limited number of degrees of freedom which allows the reduction of the computational time, which leaves the possibility to carry out parametric studies that consider different wall configurations.

• Coupled systems mechanics
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• v.10 no.1
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• pp.1-19
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• 2021

Composite nature of the masonry structures in general causes complex and non-linear behaviour, especially in intense vibration conditions. The presence of different types and forms of structural elements and different materials is a major problem for the analysis of these type of structures. For this reason, the analysis of the behaviour of masonry structures requires a combination of experimental tests and non-linear mathematical modelling. The famous UNESCO Heritage Old Bridge in Mostar was selected as an example for the analysis of the global behaviour of reinforced stone arch masonry bridges. As part of the experimental research, a model of the Old Bridge was constructed in a scale of 1:9 and tested on a shaking table platform for different levels of seismic excitation. Non-linear mathematical modelling was performed using a combined finite-discrete element method (FDEM), including the effect of connection elements. The paper presents the horizontal displacement of the top of the arch and the failure mechanism of the Old Bridge model for the experimental and the numerical phase, as well as the comparison of the results. This research provided a clearer insight into the global behaviour of stone arch masonry structures reinforced with steel clamps and steel dowels, which is significant for the structures classified as world cultural heritage.

• Structural Monitoring and Maintenance
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• v.10 no.2
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• pp.117-132
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• 2023

The most prevalent and oldest type of structure is unreinforced masonry (URM) structures; URM walls are still a widely used construction material in India and many other developing countries due to their simplicity, ease of construction, economic sustainability, and ability to be built with locally available materials. URM walls are significantly weak while carrying lateral loads. The poor performance of URM walls during earthquakes has necessitated investigating an effective method for strengthening a newly built masonry building or retrofitting an old structure. Wire mesh, being cost-effective and easily available, satisfies the requirements to strengthen new and old URM buildings. The use of wire mesh to strengthen and retrofit the URM structure is simple to use, quick to construct, and inexpensive, especially in developing nations where heavy machinery and highly qualified labour are lacking. The current paper reviews the effectiveness of steel wire mesh as a reinforcing material for enhancing masonry strength. The finding gave encouraging results for the field application of wire mesh.

• Earthquakes and Structures
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• v.6 no.4
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• pp.335-350
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• 2014

Historical masonry mosques are the most important structures of Islamic societies. To estimate the static and dynamic behavior of these historical structures, an examination of their restoration studies is very important. In this study, Kara Mustafa Pasha Mosque, which was built as a domed mosque by Kara Mustafa Pasha between 1666-1667 in Amasya, Turkey, has been analyzed. This study investigates the structural behavior and architectural features of the mosque. In order to determine specific mechanical properties, compression and three-point bending tests were conducted on materials, which have similar age and show similar properties as the examined mosque. Additionally, a three-dimensional finite element model of the mosque was developed and the structural responses were investigated through static and dynamic analyses. The results of the analyses were focused on the stresses and displacements. The experimental test results indicate that the construction materials have greatly retained their mechanical properties over the centuries. The obtained maximum compression and tensile stresses from the analyses have been determined as smaller than the materials' strengths. However, the stresses calculated from dynamic analysis might cause structural problems in terms of tensile stresses.

• Earthquakes and Structures
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• v.16 no.4
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• pp.501-512
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• 2019

In this study, seismic vulnerability assessment and seismic isolation retrofit of Bayburt Yakutiye Mosque is investigated. Bayburt Yakutiye Mosque was built in the early 19th century at about 30-meter distance to Coruh river in the center of Bayburt in Turkey. The walls of historical masonry structure were built with regional white and yellow stones and the domes of the mosque was built with masonry bricks. This study is completed in four basic phases. In first phase, experimental determination of the regional white stone used in the historical structure are investigated to determine mechanical properties as modulus of elasticity, poison ratio and compression strengths etc. The required information of the other materials such as masonry brick and the regional yellow stone are obtained from literature studies. In the second phase, three dimensional finite element model (FEM) of the historical masonry structure is prepared with 4738 shell elements and 24789 solid elements in SAP2000 software. In third phase, the vulnerability assessment of the historical mosque is researched under seismic loading such as Erzincan (13 March 1992), Kocaeli (17 August 1999) and Van (23 November 2011) earthquakes. In this phase, the locations where damage can occur are determined. In the final phase, rubber base isolators for seismic isolation retrofit is used in the macro model of historical masonry mosque to prevent the damage risk. The results of all analyses are comparatively evaluated in details and presented in tables and graphs. The results show that the application of rubber base isolators can prevent to occur the destructive effect of earthquakes.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.4
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• pp.13-20
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• 2017

Unreinforced masonry buildings are vulnerable to lateral forces, such as earthquakes, owing to the nature of the building materials, yet numerous masonry buildings remain in South Korea. Since the majority of the existing masonry buildings were constructed more than 20 years ago, it is necessary to develop economical reinforcement methods for disaster reduction. In this study, external reinforcement of masonry walls using adhesive stiffeners was proposed as a reinforcement method for such age-old masonry buildings. Six specimens were fabricated with different aspect ratios (L/H = 1.0, 1.3, and 2.0) and used in static load tests to verify the reinforcement effect. The experimental results showed that the masonry walls before and after reinforcement were ruptured by rigid body rotation and slip. In addition, the maximum strength, maximum displacement, and dissipated energy of the walls were shown to increase after applying the adhesive stiffeners, thereby verifying the excellent reinforcement effect. Furthermore, an adhesive stiffener design for unreinforced masonry walls was proposed based on the increased shear strength achieved by using conventional glass fibers. The proposed design can be used as a basis for the application of adhesive stiffeners for unreinforced masonry walls.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.5 s.57
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• pp.133-141
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• 2009

50 year-old masonry buildings which had been constructed using lime mortar have caused lots of problems because of using different material, cement mortar, when they repair them. Also, there is little information on structural capacities and details of masonry buildings built using lime mortar. In addition, it is difficult to evaluate the structural capacities of the buildings which were often constructed by untrained labors. To preserve the original masonry construction, the study on their construction materials and methodologies has to be carried out. This paper provides basic information for establishing standard details of masonry works using lime mortar in order to overcome these problems when cultural properties are repaired or retrofitted. To do this, compression tests of lime mortar were preformed with the parameters of mixing ratios, mixing material, curing time and curing conditions etc. Based on the test results, the differences between lime mortar and cement mortar were specified and the structural characteristics of lime mortar were also presented in this paper.

• Journal of the Korean Wood Science and Technology
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• v.45 no.1
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• pp.1-11
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• 2017

A lot of the energy are consumed on heating and cooling in buildings. The buildings need to minimize the heating and cooling loads for $CO_2$ emissions and energy consumption reduction. In recently, also demand of detached houses were increase while the residential culture was changed. The structure of the domestic detached houses can be divided into masonry, concrete, wood frame houses. Therefore, in this study, the heating and cooling load and energy demand were analyzed on the equal area detached house consisting of three structural methods (Masonry, Concrete, Wood frame). Layer of wall, roof, and floor were composited by structure. Thermal transmittance (U-value) of each layer was using the PHPP calculation for considering stud, such as the wood frame wall. In addition, the case of without considering for studs in wood frame wall (Non-studs) was analyzed in order to compare the difference between studs or not. Analysis was performed using self-developed heating and cooling load calculation program (CHLC) based excel and ECO2. The results of cooling and heating load and energy demand showed the highest values in the wood frame structure, and the concrete structure were confirmed to maintain a high value secondly. Two structure were determined to be disadvantageous on the energy consumption. Consequently, the masonry structure have an advantage over the other structure under the identical conditions. It was determined that if the except for thermal bridges due to the studs in the wood frame structure, it can be reduced the energy consumption.

• Journal of Korean Association for Spatial Structures
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• v.8 no.3
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• pp.83-90
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• 2008

It is hard to predict the mechanical characteristics of discontinuous stone masonry structures by the static analysis method, because of irregularity of face stones and also due to randomness of backfill materials. Inversely, one can estimate the mechanical characteristics by comparing the natural frequencies between measured and computed. The aim of this paper is to investigate the computational modeling method of ancient stone arch bridges in Korea and to find the factors influencing their dynamic characteristics. The results revealed that the rigidity of spandrel walls and backfill materials are the most important factors influencing the natural frequencies of stone arch bridges.

• Earthquakes and Structures
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• v.9 no.2
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• pp.281-303
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• 2015

The effects of infill panels on the response of r.c. frames subjected to seismic action are widely recognized. Numerous experimental investigations were effected and several analytical models were developed on this subject. This work, which is part of a larger project dealing with specific materials and structures commonly used in Italy, discusses experimental tests on masonry and samples of bare and infilled portals. The experimental activity includes tests on elemental materials, and 12 wall samples. Finally, three one-bay one-story reinforced concrete frames, designed according to the outdated Italian technical code D.M. 1996 without seismic details, were tested (bare and infilled) under constant vertical and cyclic lateral load. The first cracks observed on the framed walls occurred at a drift of about 0.3%, reaching its maximum capacity at a drift of 0.5% while retaining its capacity up to a drift of 0.6%. Infill contributed to both the stiffness and strength of the bare reinforced concrete frame at small drifts thus improving overall system behavior. In addition to the experimental activities, previously mentioned, the recalibration of a model proposed by Comberscue (1996) was evaluated. The accuracy of an OpenSees non linear fiber based model of the prototype tested, including a strut element was verified through a comparison with the final experimental results. This work has been partially supported by research grant DPC-ReLUIS 2014.