Advanced Materials Research Vols. 133-134

Abstract: The work focuses on the analysis of the seismic response of masonry building aggregates for a better understanding of the vulnerability of single structural units and of their behaviour within the aggregates. Idealized representative models are developed based on the typical characteristics of the row conglomeration typology. The seismic response of the models is evaluated and discussed by means of nonlinear dynamic analyses.

Abstract: Monastery of Stoudios, dated back to the reign of Eastern Roman Empire, is known to be the oldest surviving –albeit partially- religious building in Istanbul. During sixteen centuries, the building has been exposed to several earthquakes, fires and other minor disasters which have caused considerable damages and partial destruction in some of its sections. As a part of a general master plan for the structural condition assessment of historical buildings and monuments of Istanbul, this study aims to evaluate the seismic resistance of the monastery against future excitations. The expected failures and corresponding preventive/controlling repairs and strengthening measures will also be discussed in the article.

Abstract: Earthquakes are recurring natural phenomena that cause cumulative damage to earth constructions that can lead to their collapse. The discovery of earthen architectural heritage in Peru, has led to the re-exposure of adobe buildings, increasing their vulnerability to seismic activity. How can we prevent protect them from further damage their loss and Due to their gradual and progressive destruction, earth constructions located in seismic areas constitute a critical and unique case. The structural response of stone masonry joined with mud mortar depends on the weakest of their construction materials: earth. This paper presents the criteria for structural conservation of earthen architectural heritage and tools for seismic-resistant reinforcement developed by field experts during the last 25 years. The concepts of reinforced earth and liquid mud injection, developed by the Pontifical Catholic University of Peru (PUCP) with support from the Getty Conservation Institute (GCI), are also included in this work. The article also analyzes recent cases of the re-intervention of earth monuments initially restored during the last century and re-destroyed by more recent earthquakes; offers solutions to this situation, ranging from the safest and friendliest to the most aggressive ones. Finally, I concludes expressing the urgent need to reassess the conservation criteria accepted by the International Charters ratified by ICOMOS and UNESCO regarding earthen architectural heritage located in seismic areas.

Abstract: Insufficient ductility and lack of integrity have caused extensive damages and undesirable responses in masonry buildings in past earthquakes. These types of structures are distributed all over Iran and the vulnerability assessment of such structure is one of the main concerns between structural engineers. Developing an advance finite element model to simulate the behaviour of a masonry structure is a very complicated procedure which may not be practical and applicable in most cases, so many attempts have been performed to find simple methods for analysing these structures. The Equivalent Frame Method is one of the well-known methods which is rather simple and could be used for vulnerability assessment of some historical structures like Iranian caravanserais. The architectural configurations of Iranian caravanserais were regular and symmetric. When the arrangement of walls and openings are modular it is convenient to model the piers and spandrels as a frame type columns and beams. The simplicity of the conventional Equivalent Frame Method sometime leads to an inaccuracy of the assessment, therefore some modification for the upgrading of this method has been proposed. Using the shell elements beside the frame elements in a modelling procedure may eliminate some disadvantages of the conventional Equivalent Frame Method. In this study a modification has been proposed to improve the upgraded Equivalent Frame Method ability in predicting the failure modes of the masonry walls such as, toe crashing. The proposed modification has been used in the static nonlinear analysing of a masonry structure by the Equivalent Frame Method. The given results have acceptable reconciliation with practical reality and it seems to be useful, especially in a rapid assessments.

Abstract: Synthetic methods for the diagnosis of structures and particularly for their vulnerability assessment rely on simplified calculations and visual inspection. Their effectiveness strongly depends on an accurate calibration of the procedure by which data are collected. A recent methodology for the seismic vulnerability assessment of timber roofs in historical buildings has been applied to the Thun Castle during a study for its rehabilitation. The purpose was twofold: testing and calibrating the procedure on a heritage structure and estimating the capability of the roof structure to resist seismic action, as required in a zone of low but not negligible seismicity.

Abstract: A method for non-linear dynamic analysis of wall masonry structures is presented. The method takes advantage of a Generalized Matrix Formulation (GMF) for the serviceability and ultimate analysis of structures composed of arches and/or masonry walls, in which open and solid walls are described as equivalent frame systems. This formulation has been complemented with a cyclic constitutive model and an algorithm for the integration of the equation of motion, resulting in a numerically efficient method for non-linear analysis in time domain of complex masonry systems.

Abstract: The “Palazzo della Civiltà Italiana” is a monumental building characterized by a reinforced concrete structure composed of parallel (cast in situ) portal frames and composite (reinforced concrete + hollow bricks floors which spans between adjacent portals: a common construction technique in Italy. The floors being characterised by a large span of about 10.0 meters. The construction took place between 1939 and 1943, most likely according to the Italian building code published in 1939. The authors have coordinated a comprehensive experimental campaign aimed at (a) the identification of the characteristics of the structural materials and members, and (b) the identification of eventual damages. Based upon the experimental results a number of analytical and numerical investigations have been developed in order to assess the structural reliability of the “Palazzo” which up to date still is remains in its “original” configuration, as no substantial intervention of structural retrofit or rehabilitation have been implemented so far. These analysis allowed to identify two major reliability issues: (i) the load bearing capacities of the floors do not allow the intended use, and (ii) the seismic vulnerability of the building does not satisfy the reliability standards required by current codes. On the basis of all data acquired and investigations performed, a simple (non invasive) structural retrofit solution capable of bringing the “Palazzo” to the level of structural safety required by current codes is identified.

Abstract: This work focuses on the seismic risk evaluation of the Concordia temple, situated in the Valley of the Temples in Agrigento (Italy). In the paper a general methodology to assess the seismic vulnerability, to be applied also to any kind of structures composed of stone blocks, is proposed. The vulnerability assessment has been conducted by means of equivalent nonlinear static analyses along the principal directions of the structure and the subsequent identification of equivalent single degree of freedom systems. Furthermore, the seismic vulnerability has been expressed both in a deterministic and a probabilistic context by evaluating the severe damage probability.

Abstract: Each earthquake represents a particular moment in the history of the affected region. The seismicity in Italy reaches frequently high values, what makes it a country particularly affected by this kind of natural disasters. Historical constructions (in particular masonry ones) are structures that show a high vulnerability to the type of loads introduced in the sequence of a seismic event. This paper focus on the effects of the 6th of April 2009 earthquake, that affected the region of Abruzzo (Italy), over the historical buildings of the region, in particular churches, by establishing a set of different objectives directed to the understanding of their structural behavior and to the assessment of the extent of post seismic damage in this structures. During the emergency period that followed the earthquake, many churches and other historical constructions (towers, walls, palaces, etc…) were surveyed, according to the official 1st level damage survey forms for Cultural Heritage (C.H.), by the workgroup of the University of Padova (UNIPD). The information collected from these surveys was later inserted and organized in a database. A statistical work is presented, illustrating the referred information and focusing on the data related with the damage assessment of the considered monuments. This work presents an intuitive overview of the seismic effects over the surveyed churches, allowing not only to better understand the response of these structures to this particular action, but also correlating the earthquake data with its effects on the churches.

Abstract: The church of S.Agostino in L’Aquila was built at the beginning of XVIII century, replacing an older church collapsed during the strong earthquake of 1703. The building has a central layout. During April 6th earthquake, it suffered many damage. The lantern collapsed. Severe cracks concerned the hall-drum-dome elliptical system, the apse and the bell tower. Moreover, the façade was subjected to an overturning mechanism. The elliptical layout of the building induced a mainly longitudinal seismic response. In the paper, a extensive description of the damage is provided. Moreover, the seismic behavior of the church is discussed on the basis of observation of damage and vulnerability features of the structure. A correlation between damage, vulnerability and seismic actions is finally proposed.