Numerical model to account for the influence of infill masonry on the RC structures behaviour

It is a common misconception considers that masonry infill walls in structural RC buildings can only increase the overall lateral load capacity, and, therefore, must always be considered beneficial to seismic performance. Recent earthquakes have showed numerous examples of severe damages or collapses of buildings caused by structural response modification induced by the non-structural masonry partitions. From a state-of-the-art review of the available numerical models for the representation of the infill masonry behaviour in structural response, it was proposed an upgraded model. The proposed model is inspired on the equivalent bi-diagonal compression strut model, and considers the non-linear behaviour of the infill masonry subjected to cyclic loads. The model was implemented and calibrated in a non-linear dynamic computer code, VISUALANL. In this paper, it is presented the proposed model and the results of the calibration analyses are briefly introduced and discussed

Numerical Analysis of the Tetrapylon Roman's Triumphal Arch of Tebessa: A Case Study.

The Tetrapylon  Roman Triumphal Arch or commonly called  'Caracalla Gate', located  in Tebessa City (Northern Algeria), is considered as one of the most distinctive type of arches associated with the ancient Roman's architecture. This historical monument, erected in the 3rd century, was dedicated to the Roman Emperor Caracalla. In the 6th Century the Caracalla gate was enclosed in the Byzantine old city, built by the General Salomon. Although the monument is still standing, over time, it suffered apparent damages. The conservation and restoration of this monument is actually a major preoccupation for the concerned authorities. In this paper a 3D numerical analysis of the deformations and global stability of the gate are presented. The numerical results obtained were compared to previous site survey and measurements, and were found to be in good agreement. The results revealed that part of the monument damages and deformations occurred following the construction of the Byzantine walls.  In its actual state, the monument was found sufficiently stable, and the restoration would not affect its firmness, if appropriate materials and techniques are deployed

Experimental assessment and retrofit of full-scale models of existing RC frames

PSD tests on two full-scale models of existing non-seismic resisting RC frame structures are described. The testing program covered several aspects, namely assessment of seismic performance of existing frames without and with infill panels, retrofitting of the bare frame using Selective Retrofitting techniques, strengthening of the infill panels using shotcrete and retrofitting of the frame using K-bracing with shear-link dissipators. The main results from the tests are summarized and discussed and the conclusions are drawn. The tests on the bare frame have shown how vulnerable are existing structures constructed in the 60’s and the beneficial effects of infill panels were confirmed from the tests on the infilled frame. Important improvements, in terms of seismic performance, were achieved by the retrofitting of the frames. However, it was also confirmed that strengthening of the existing infill panels in poorly detailed frames may lead to dangerous ‘local’ failures, such as the shear out of the external columns

Combining ground penetrating radar and seismic surveys in the assessment of cultural heritage buildings: The study of roofs, columns, and ground of the gothic church Santa Maria del Mar, in Barcelona (Spain)

Combined non-destructive techniques are applied in the study of a historical building in Barcelona. Santa Maria del Mar is a magnificent Mediterranean gothic church built between 1329 and 1383. Two of the most important characteristics of this building are the slender columns and the almost flat rooftop. This structure, used to create a visual impression of a unique space, transmits high loads to the tall columns. Previous to restoration, vaults, roofs, and columns were extensively assessed with non-destructive tests, in order to improve the knowledge of those structures. This information will be used in further simulations to analyse load distributions at each part of the structure. Ground and floor were also studied. The analysis of the columns was based on ground- penetrating radar (GPR) surveys and on seismic tomography. Finally, the dynamic behaviour of the structure was determined by seismic monitoring of the main nave and the bell tower. Results obtained at the radar survey highlight the existence of unexpected anomalies in homogeneous materials, supporting the hypothesis of an inner structure between arches and roof composed by hollow elements. Seismic tomography defined the inner geometry of the columns and detected some damage or lower quality stone in various zones. Seismic monitoring established the perfect junction between the bell tower and the main nave. GPR survey on the floor allowed detecting a large number of graves, and some images suggest the existence of large underground walls and some of the foundations of the main façade.Peer ReviewedPostprint (published version

The 1985 Chile earthquake: Structural characteristics and damage statistics for the building inventory in Vina del Mar

The Chile earthquake of 3 March 1985 resulted in an effective peak acceleration of 0.36g in the coastal city of Vina del Mar. The city had an inventory of over 400 reinforced concrete buildings ranging in height from 5 to 23 stories. The observed behavior of the buildings is interpreted in relation to the physical characteristics of the structural systems.National Science Foundation Grant ECE 86-0378

Structural vulnerability of Nepalese Pagoda temples

Nepal is located in one of the most severe earthquake prone areas of the world, lying between collisions of Indian to the Eurasian plate, moving continuously, resulting in frequent devastating earthquakes within this region. Moreover, different authors refer mention that the accumulated slip deficit (central seismic gap) is likely to produce large earthquakes in the future. Also, the analysis of the available information of previous earthquakes indicates the potential damage that can occurs in unreinforced traditional masonry structures in future earthquakes. Most of the Nepalese pagoda temples were erected following very simple rules and construction details to accomplish with seismic resistance requirement, or even without any consideration for seismic resistance, during the period of Malla dynasty (1200-1768). Presently, conservation and restoration of ancient monuments are one of the major concerns in order to preserve our built heritage, transferring it to the future generations. The present paper is devoted to outline particular structural fragility characteristics in the historic Nepalese pagoda temples which affect their seismic performance. Moreover, based on the parametric analysis identified structural weaknesses/fragilities of pagoda topology, the associated traditional building technology and constructional details

The effect of masonry infill walls on the reinforced concrete frames behavior under lateral load

The reinforced concrete structures with masonry infill walls are widely used to construct buildings in Algeria, as in many parts of the world. According to earthquake analysis, this type of construction can undergo serious damage under seismic load. The interaction between the infill wall and the surrounding reinforced concrete structure is considered a key parameter, which could trigger damage and even collapse in self-stable frame buildings. To study the behavior of this type of structures and the wall–frame interaction, four half-scale single-storey, single-bay reinforced concrete unfilled and unfilled frames were constructed and tested under in-plane lateral load. Furthermore, the experimental results were analyzed using the Digital Image Correlation (DIC) technique giving a detailed analysis of displacement and strain fields. The wall–frame interaction was evaluated in terms of displacement field evolution and interface slip in the contact contour. The masonry infill wall demonstrated a significant influence on the in-plane lateral response of this type of structure. The analysis of the results of the experiment are discussed in this paper

The 19th entury iron architecture of industrial buildings. A formal and constructive comparison between two case studies

The paper analyzes the features of the 19th century industrial architecture and the application of metallic structures combined with formal and architectural expressions that frequently concealed or mitigated their presence. The mix of engineering features for the industrial purpose and familiar perceptions of the traditional architecture is one of the characteristics of this typology. The cases - both belonging to the mining industry of the 1800s - feature both the structural innovations in the use of metallic - masonry structures and formalism that recall the Eclectic and aesthetic motifs as a mean to enhance the industrial function and the technological expression. The metallic elements are in fact frequently employed in the most important sections of the buildings and testify the influences of both the technical advance of the constructive theories and the stylistic formulas that, although belonging to a more aulic architecture, intensify the productivity and the performances. Finally a proposal of reuse for one of the case study aims to valorize the duplicity of the formal and the technological approach for this typology in order to give a new purpose to this symbol of the industrial epopee.Peer ReviewedPreprin