Advanced Materials Research Vols. 133-134

Abstract: The document concerns with the design and study of a large masonry model of Hagia Irene in Istanbul. The goals of experimentation were to acquire a deeper structural behaviour knowledge than that possible to acquire with numerical models only and to assess the effectiveness of the consolidation works foreseen on Hagia Irene. The scale factor chosen is equal to 1:10. The tests were arranged into two different phases: for not reinforced and reinforced scale model .The displacements of the markers placed on the structure were registered by an innovative monitoring technique measuring 3D motion time histories.

Abstract: Masonry walls resist most of the lateral loads in some Chinese historical architecture. To investigate the seismic properties of these load-bearing masonry walls, blocks in a typical Chinese old building undergoing retrofit are reserved. Compressive test specimens and wall panel specimens are constructed using these blocks and lime mortar. Mixing of the lime mortar is similar to that used in the old building. Material tests and pseudo-static tests are then performed. The damage modes and hysteretic curves of the wall panel specimens are studied. The test results are expanded through computer simulation. Some characteristics of the load-bearing masonry walls are summarized based on the test and simulation results. The proposed methodology and results can be referred to in further researches on seismic properties of historical masonry architectures.

Abstract: The Palace of the Dey at Algiers is located inside the Citadel of Algiers which was built in the 16th century (1516) by ‘Arrudj (Barbarous). The citadel is located at the higher part of the city and was the first military building at that time. The citadel was the janissary barracks and initially contained a powder keg, a walk, Janissaries residence places and their mosque. Starting from the 18th century appear new constructive strata. In 1716 some part of this military edifice was destroyed by an earthquake. In 1783 the Spanish bombarded Algiers and a bomb fell into the first storey of the palace. The architectural transformations took place in 1817 when the Dey ‘Ali Khūdja lived at the janissary’s barracks. Thereafter and during 12 years several buildings were added to this whole defensive structure as the second and the third floors of the palace, the Dey’s mosque, the bath, the Bey’s palace and the winter garden. During the French colonization, the palace undergoes other transformations as the destruction of most of the rampart of the city contiguous to the palace which caused its instability and which until today accentuates its vulnerability. The lack of maintains, the abandonment and the bad restoration which took place during the 20th century increased this vulnerability. This work based on a visual screening will present the various aspects of vulnerability due to static weaknesses of the angles and absence of wind-bracing of this palace.

Abstract: Traditional Rammed earth houses, which possess people traditional cultures, are still widespread in rural areas of western China. However, the earth houses damage is usually serious due to its poor seismic resistance. A simple and low-cost method to reinforce the rammed earth wall is put forward in the paper. In order to test the reinforcement effectiveness, shake table testing for both the wall panels with and without structural reinforcements have been carried out. The performances of the wall panels during dynamic testing are presented and discussed briefly. The result of the test demonstrated the effectiveness of the reinforcement method on improving the seismic capacity of the rammed earth wall. The reinforcement can restrain the crack development and increase the structural integrity of the wall panels. The method can be applied to both existing and new building rammed earth houses.

Abstract: In this paper the seismic response of four church buildings in the l’Aquila April 2009 earthquake is analyzed. The buildings are: St. Giusta church, St. Maria di Collemaggio Basilica, St. Silvestro church and St. Pietro di Coppito church. The analyses are carried out by employing a “two-step” procedure suggested by the authors and already applied to similar case studies. The first step consists in three-dimensional linear analysis, while in the second step, two-dimensional non-linear analyses of macro-elements are carried out. The results coming from the two-steps, allow for understanding the observed damage and for approximately assessing the seismic level of the building.

Abstract: The recent earthquakes have shown the high vulnerability of the façades of churches, which detached from the longitudinal walls and failed by overturning. While being well known, this collapse mechanism is still under study as regards the contribution provided by the connections with longitudinal walls as well as the influence of masonry morphology. Three churches with single nave, which have suffered the abovementioned damage during the April 2009 earthquake in L’Aquila, Italy, are considered in the present paper. The seismic behavior of the churches is analyzed taking into account the effective morphology of masonry, by means of 2D Distinct Element analyses under both increasing static forces and dynamic acceleration pulses. The resulting capacity curve is then evaluated and compared to the case of a rigid body overturning showing to what extent the latter model provides a reliable estimate of the seismic behavior of the façade.

Abstract: The adaptability is important in the technological reformation of industrial building. Bracket girder and cut column (BGCC), are widely used to expand the space and to increase the inner working room of the buildings. Reformation of the exiting industrial building is limited to the continuous and non-stop working and (must be) in service and the reformation is required to be non-stop. Industrial buildings, especially the industrial single-storey workshops mostly belong to static determinate and low-order static indeterminate structures and many risks may be faced during the BGCC reformation under the complicated working conditions, such as variable structure risk, structural failure caused by overload, injuries of workers resulted from the unsafe construction, injuries of the production workers due to construction operation, etc. Research on the safety risk management of the industrial building BGCC reformation is of great significance for ensuring the technological transformation of industrial enterprises and controlling the risks from the reformation of adaptability of industrial buildings in China. Consequently, based on the approaches of risk identifying on work decomposition structure(WBS) and the questionnaire, the whole process design and construction management methods are proposed to control the risks in the reformation of the exiting industrial buildings, and the total management of construction process can be used to reduce injury risks of engineering staffs. In this paper, the technological key points of the whole process design control and construction management are discussed in details based on examples of BGCC reformation of exiting industrial single-storey buildings and the corresponding injury risk management methods are suggested.

Abstract: In this study The Church of St. Sergius and Bacchus was modeled by Finite Element Method and was put through various tests to determine its structural system, earthquake behavior and structural performance. The geometry of the structure, its material resistance and ground conditions isn’t enough to model a historical structure. Additionally, you need to calculate the dynamic charac-teristics of the structure with an experimental approach to come up with a more realistic and reliable model of the structure. Therefore, a measured drawing of the structure was acquired after detailed studies, material test-ing were made both at summer and winter to examine the seasonal changes and soil conditions were determined by bore holes and exploratory wells dug around the structure. On the other hand, vibra-tion tests were made at The Church of St. Sergius and Bacchus to analyze the structural characteris-tics and earthquake behavior of the building. Structural modeling of the building, modeled by the Finite Element Method, was outlined by determining its free vibration analysis in compliance with experimental periods. Vertical and earthquake loads of the structure were determined by this model. Keywords: Finite element method, earthquake behavior, church

Abstract: Since earthquakes such as Northbridge (1994) and Kobe (1995) gave the impetuous for the development of performance-based design methods, engineers have been strenuously working to the improvement of the seismic behaviour of structures; in fact, high ductility frames, as well as damping and isolation systems, are nowadays common practice in seismic prone areas. Heritage buildings constitute an odd case: many historic centres are still considerably affected by seismic events (L’Aquila, 2009) due to the lack of a methodical retrofit and this, where applied, is still largely based on the increase of stiffness and capacity, without the due care for precious finishings. In order to address the lack of specific passive systems for heritage buildings, the authors have developed two typologies of dissipative devices that can be integrated in traditional steel anchors and installed within the masonry at the joints of perpendicular walls, where out-of-plane mechanisms are likely to form due to poor quality connections. Both prototypes, one based on the plasticity of steel, the other relying on friction, were tested as isolated elements in pseudo-static regime for proofing and fine tuning, and in a dynamic range typical of the seismic frequency content to validate the stability of dissipative loops. The paper focuses on pull-out tests aimed to analyse the behaviour of the hysteretic prototype in respect to traditional steel anchors in masonry panels with low shear capacity. Finite Element (FE) models were also developed and calibrated applying the data from tests. Experimental and computational results are discussed in the following; the need for further theoretical work concludes the paper.

Abstract: This paper should be treated as continuation of considerations placed in the paper (Ciesielski et. al. 2004), where a strengthening of cracked masonry arches, based on CFRP laminates anchored in the brick walls, was presented. The efficiency of CFRP strengthening was tested by a sudden failure of the building caused by inappropriate repair intervention in fundaments and supported soil. Work of the arches strengthening survived the structure from catastrophic consequences. In the paper the failure process is reported and measurements of settlement and cracks width changes are presented. The rescue intervention in the cracked building is also described.