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Slow-moving landslides cause significant economic losses associated with damage to facilities and interruption of human activity in mountainous regions and along river valleys. Physical vulnerability of structures exposed to slow-moving landslides is a required input for informed risk mitigation decision-making. However, the quantification of this vulnerability is still a major challenge. Few studies have been completed on this topic due to the limited historical data of the building damage associated with the comprehensive descriptions of the landslide mechanism. This research presents an experimental approach to investigating the mechanism of damage development and evolution on masonry buildings exposed to ground tension cracks associated with slow-moving landslides. A one-tenth scale model of a masonry building was designed and tested on the newly developed test table. The details of the testing setup are presented in this paper. The scaled model was constructed using sintered clay brick masonry and an unreinforced concrete foundation. An artificial tension crack was opened under the scaled model through the application of loading steps, in the direction parallel to the model foundation. The internal strains and associated forces developed on the scale model walls and foundation were measured by strain gauges. It was observed that the damage ranged from cracking to partial out-of-plane failure of the walls and the foundation. The damage level increased with the propagation of the tension crack on the test table. The final observation results were compared and validated against the field observations of damaged buildings on slow-moving landslides in TGR area in China. The experimental loading device simulated building damage caused by ground horizontal displacements and can bridge the gap in understanding the effects of slow-moving landslides on structures. It provided a new way to analyze the vulnerability of masonry structure under horizontal movement patterns of slow-moving landslides. [ABSTRACT FROM AUTHOR]

The article informs about archaeological descriptions compared to its dismantling in the 19th century for the masonry corresponding to the foundations with different networks in stratigraphic relationship. Topics include stoppage of work as soon as the construction of the gate began as mentioned in municipal deliberations in the mode of construction; and work undertaken for the new door construction for the pre-existing masonry.

This paper shows the results of a numerical analysis carried out using the equivalent frame method, which aimed to investigate the three-dimensional behaviour of masonry buildings with shallow foundations subjected to different settlement troughs on a set of soil types. The obtained results are first expressed in terms of deterministic relationships between the adopted intensity measure (the maximum differential settlement) and a newly defined engineering demand parameter (the vertical drift ratio). Then, following a probabilistic approach, fragility curves pertaining to the modelled masonry buildings are generated, and their usefulness in preventing the occurrence of a serviceability limit state is discussed. [ABSTRACT FROM AUTHOR]

Building monitoring and protection are important components of underground projects in urban areas. Typically the procedures applied for the assessment of settlement-induced damage to buildings are based on simplified assumptions that do not take into account soil–structure interaction. Assessment methods based on the relative stiffness between the structure and the soil exist, but they are rarely applied in practice due to concerns about the accuracy and reliability. The primary aim of this work is to use the large amount of monitoring data provided by the Crossrail project in London to improve understanding of building performance and existing damage assessment methods. The paper gives an initial overview of the available monitoring data by presenting four representative case studies for load-bearing masonry buildings on shallow foundations. Structural data are then used to evaluate the consistency of predictions produced by different relative stiffness formulations. The results show the effect of building stiffness on the soil surface settlements and clarify the effects of various assumptions made during prediction. The conclusions highlight opportunities to improve prediction procedures and the need for more detailed monitoring data for future tunnelling projects. [ABSTRACT FROM AUTHOR]

Five long-span reinforced concrete (RC) frame specimens with various configurations of masonry infill walls were tested under lateral quasi-static cyclic loading. The specimens were half-scale models of gravity-load-designed (GLD) RC frames of typical school buildings, and comprised one bare frame and four frames with either a full infill, partial-height infill, central-opening infill or side-opening infill. All the specimens were heavily instrumented with strain and displacement sensors to gain in-depth information on the interaction effects between the frame and infill walls. The test results showed that the interaction mechanism varies greatly from case to case. For example, the fully infilled wall behaved like two inclined compression-only struts but with characteristics quite different from those of conventional diagonal struts. The infill wall with a side opening behaved just like one strut, actively engaging only when the wall was pushed by the frame, and thus creating an unsymmetrical cyclic force-deformation behaviour of the infill frame. [ABSTRACT FROM AUTHOR]

Fabric Reinforced Cementitious Matrix (FRCM) materials are composed of a dry fiber grid embedded in an inorganic matrix, which may contain short fibers. These materials are particularly well-suited for the reinforcement of masonry structures due to their high compatibility with the substrate, vapor permeability and durability against environmental agents. The most important information needed for the characterization of these composite systems, for use as strengthening materials of masonry structures, are the tensile behaviour and the shear bond properties. A Round-Robin Test was organized by the RILEM Technical Committee 250-CSM and the Italian association Assocompositi in order to experimentally characterize different FRCM systems composed of PBO, carbon, glass, basalt, aramid and steel textiles embedded in cementitious or lime-based mortars. The systems were tested at different universities and research centers in Europe in order to investigate the influence of samples preparation, test set-up and instrumentation. In this paper, the experimental tests performed on Carbon-FRCM systems are described and discussed. Important aspects are analyzed herein: differences in the testing procedure and instrumentation, influence of textile geometry and mechanical properties of the constituent materials, importance of specimen preparation and curing conditions. Moreover, a comparison between tensile and shear tests is reported in order to determine a reliable procedure towards the complete characterization of an FRCM material. [ABSTRACT FROM AUTHOR]

Structures may be subjected to damage and deterioration over different timescales, and monitoring their health status may allow to perform maintenance actions before the functionality limit is reached. Masonry arch bridges, in particular, are sensitive to the bearings loss produced by scour of the streambed soil at the pier foundations. In this study, we measured the changes in the elastic properties of a 1:2 scaled model of a masonry arch bridge built in the laboratory to study the evolution of the damage mechanism related to the application of foundation movements. Specifically, the bridge is realized to model the effect of erosion of the ground underneath the central pier. We analysed the accelerometric records acquired along the structure generated by a sledgehammer hitting the bridge walls. We used the method of coda wave interferometry to detect the changes in the elastic properties of the medium. After selecting the specific frequency band exciting coda waves, we progressively measured the time lag between signals acquired in the intact and two damaged stages of the bridge for each source-receiver couple, and we fit the data to get the relative wave velocity changes. We found that the average relative velocity changes for the two damaged steps are Δv/v = -5.08 ± 0.08% and Δv/v = -8.2 ± 0.6%, consistently measured at all the analysed source-receiver couples. These values correspond to an average estimation of the velocity changes occurred within the structure, because the associated wavelengths are comparable with the bridge size and the damage is spread over a large portion of the structure. [ABSTRACT FROM AUTHOR]

Unreinforced masonry walls subjected to out-of-plane horizontal bending can fail by two alternate modes: stepped failure along the brick-mortar bond, or line failure cutting directly through the bricks. Because of random variations in material properties throughout a panel and the tendency for failure to occur across the weaker elements, vertical cracks will generally exhibit a combination of the two modes. This paper develops a pair of analytical methodologies that treat this phenomenon using a stochastic approach. The first part deals with calculating the ultimate moment capacity by allowing for the weakening effect associated with the mixed (stepped and line) mode of failure. This effect is quantified in terms of strength-reduction factors for mean and characteristic (0.05 quantile) values of strength, which may be applied toward generic ultimate strength design. The second part deals with estimating the relative probability of each failure mode and the probability distribution for the relative proportions of each failure mode along a crack. This is of particular relevance to seismic performance because the two failure modes lead to significantly different postcracking behavior. [ABSTRACT FROM AUTHOR]

Investigating the behaviour of buildings is extremely useful for planning interventions aimed at their safeguarding, although hardly affordable over large urbanized areas. In this regard, DInSAR-derived building settlements can provide a valuable contribution. This paper presents a procedure tailored for deriving empirical fragility curves for buildings that might be affected by differential settlements on the basis of the combined use of DInSAR data and the results of damage surveys. The case studies deal with two municipalities in The Netherlands where masonry buildings mainly rest on soft soils (i.e. peats and organic clays). The behaviour of buildings with different foundation types (i.e. shallow and deep) is analyzed and a check of the performance of a restored foundation is carried out via the analysis of pre- and post-intervention DInSAR-derived settlement trends. [ABSTRACT FROM AUTHOR]

This research is focused on the experimental characterisation of the compressive behaviour of masonry in existing buildings. The proposed technique is based on in situ core drilling of masonry members. Two walls were built making use of terracotta handmade bricks and lime mortar, without cement, to reproduce a low-strength historical masonry. Core samples were extracted from the walls and then regularized to perform a non-standard compression test in the laboratory. Stack-bonded prisms were also tested under compression. A direct comparison is made between the results from the proposed non-standard tests on core samples and the tests suggested by the available standards on prismatic samples. The proposed minor destructive technique shows to be effective for the mechanical characterisation of existing masonry structures, including historical ones. [ABSTRACT FROM AUTHOR]

Masonry arches are typical structural elements of existing masonry constructions. Many existing masonry buildings and bridges in Europe, and indeed in many other parts of the world, are quite old and consequently may show defects and/or degradation. Such defects and degradations in masonry constructions may be caused by different factors, both environmental and human. One of the most common defects that develop over time in masonry structures involves local or uniform reduction in the thickness of the structural elements. This paper uses limit analysis to examine the influence of local thickness reductions on the seismic capacity of masonry arches: in terms of collapse acceleration and changes in collapse mechanism. [ABSTRACT FROM AUTHOR]

Due to the low tensile strength of masonry perpendicular to the bed joint, masonry wall panels have non-linear material properties. Assuming simple elastic constitutive laws, this article presents two modelling variants, which consider the lack of tensile strength in a simple manner. Both variants are investigated for their advantages and disadvantages. In a second part of the article, the application of the methods will be illustrated through the example of a four-storey building. [ABSTRACT FROM AUTHOR]

This paper describes the results of an experimental and numerical study that focused on multi-directional behavior of unreinforced masonry walls and established the requisite of the related proposed design equations. The tests were conducted following several sets of multi-directional loading combinations imposed on the top plane of the wall along with considering monotonic and cyclic quasi-static loading protocols. Various boundary conditions, representing possible wall-roof connections, were also considered for different walls to investigate the influence of rotation of the top plane of the wall on the failure modes. The results of the tests were recorded with a host of high precision data acquisition systems, showing three-dimensional displacements of a grid on the surface of the wall. Finite element models of the walls are developed using the commercial software package ABAQUS/Explicit compiled with a FORTRAN subroutine (VUMAT) written by the authors. The experimental results were then used to validate the finite element models and the developed user-defined material models. With the utility of validated models, a parametric study was performed on a set of parameters with dominant influence on the behavior of the wall system under in-plane and out-of-plane loading combinations. The experimental and numerical results are finally used to investigate the adequacy of ASCE 41 empirical equations, and some insights and recommendations are made. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This article is written against the backdrop of the work of the European standardisation committees on the amendment of EN 1996-1-1 [N 4] which will also exert an influence on the design of reinforced masonry in Germany. This paper focusses on the design approaches of DIN EN 1996-1-1 for untensioned reinforced masonry beams under shear load in the ultimate limit state (ULS). Proposals are made to discuss their revision. The contents of E DIN 1053-3 [N 3] and of the final draft of the guideline 'Flat Lintels' [7] are taken into account. [ABSTRACT FROM AUTHOR]

The recent earthquakes in Italy demonstrated the extreme vulnerability of historical and cultural structures. Masonry vaults, which represent artistically valuable elements of these constructions, have been recognised among the most vulnerable elements. Traditional vault retrofit methods, such as buttresses or ties, are still widely adopted. These retrofit methods prevent differential displacements between vault supports (e.g., abutments, masonry piers and loadbearing walls). However, the pier differential displacement is not the only vulnerability source for vaults, and in many cases, further retrofit interventions are needed. Innovative retrofit methods based on inorganic matrixes, such as IMG, are aimed to prevent hinge mechanism failures. Such methods are suitable to be applied on vaults already retrofitted using traditional methods. The knowledge of the seismic behaviour of a vault, once the differential displacement between the supports is prevented, can be crucial to the assessment of potential further vulnerabilities of vaults already retrofitted with traditional methods. However, a deep knowledge of vault seismic behaviour is still lacking from an experimental point of view. Indeed, to date, few dynamic experimental studies have been conducted. Therefore, to investigate the seismic behaviour of masonry barrel vaults, several shaking table tests were performed on a full-scale specimen before and after the retrofit interventions. The tests investigated the main seismic properties of the tested structure and clarified the cracking mechanisms and capacity improvement due to the retrofit interventions. A comprehensive overview of the main results of the experimental tests has been presented. [ABSTRACT FROM AUTHOR]

The present paper deals with the problem of the detachment of fiber reinforced polymer (FRP) from a masonry support. In particular, a new interphase model simulating the mechanical bond between masonry and FRP is proposed. It is obtained as a system of two interfaces: one reproduces the response of the glue and of the skin-deep layer and it is characterized by a linear elastic behavior whereas the second describes the nonlinear response of the detachment layer. The effect of the possible confinement due to the stress components acting in the plane of the detachment layer is also considered. Two numerical applications are reported. The first illustrates a comparison between the experimental laboratory tests and numerical simulations, showing the good performances of the proposed model. The second application is specifically devoted to the investigation of the effects of the presence of mortar joints in the detachment mechanism. [ABSTRACT FROM AUTHOR]

The fundamental frequency of a structure enables better assessment of its seismic demand for an efficient design and planning of its maintenance and retrofit strategy. The frequency is independent of the type of external loads, however, depends on structural stiffness, mass, damping and boundary conditions. In the case of slender masonry structures such as towers, minarets chimneys, and pagoda temples, it is influenced by mass and stiffness distribution, connection to adjacent structures, material properties, aspect ratio and slenderness ratio. In this present article, the data collected from various literature reviews on the slender masonry structures regarding dynamic, geometrical, and mechanical characteristics have been correlated to identify the major parameters influencing the fundamental frequency of such structures. The database has been used for developing an empirical formulation for predicting the fundamental frequency of such structures. The comparison between the experimental fundamental frequencies and the estimated fundamental frequencies are carried out in order to define reliability and accuracy of these empirical formulae. [ABSTRACT FROM PUBLISHER]

This paper describes a systematic approach of inspection, diagnosis, and repair for masonry walls and their claddings, aiming at facilitating the inspection process and deciding on the repair of these elements. It also helps to combat their degradation. Based on a visual analysis, the inspector is able to identify anomalies and use the proposed system tools to establish correlations with its source, delineate an accurate diagnosis, and determine the best repair technique. The tools that allow a faster and simpler inspection and decision are presented here. The nature of the anomalies, their related causes and appropriate repair techniques are classified, listed, and then related through correlation matrices to create a database. This equips the inspectors with the information they need about the pathology in masonry walls, as well as its classification through suitable terminology, so that a statistical analysis can be performed to find the chief causes of the anomalies. The system was developed under a strategy of proactive maintenance, and it represents an innovation that is as useful to rehabilitation in southern Europe as it is in other regions where masonry walls are a widely used technique. [ABSTRACT FROM AUTHOR]

Masonry structure is the main form of Chinese urban and rural housing construction structure. And heavy casualties and huge economic losses are caused by the damages of masonry structures in the previous destructive earthquake. So the failure modes of masonry structures are analyzed in the paper. ABAQUS software was used; and the Xuankou High School Student Dormitory of masonry structure in Yingxiu town, severely damaged under the Wenchuan earthquake, was taken for example. The influence of the stiffness ratio of pier between windows and spandrel on the failure modes of masonry structures is discussed. The results show that the failure modes in the earthquake could be changed by controlling the stiffness ratio. Suitable stiffness ratio helps proper design of masonry structures. [ABSTRACT FROM AUTHOR]

Drift-sensitive seismic damage to the non-structural masonry infills of framed buildings is one of the most detrimental effects of relatively weak earthquakes. Current codes prescribe relevant verification procedures for building design. However, these codes permit assessment of interstorey drift ratios based on analysis of bare frames, without taking into account the great influence of masonry infills on drift demands. In this paper, the degree of correlation between drift ratios of bare and infilled frames is investigated by multivariate statistical methods, in particular, that of canonical correlation. A number of frames with and without infills are analysed, using both artificial and recorded accelerograms, to compare the drift demands from a statistical standpoint. The analysed frames differ in number of storeys, stiffness of infills, ductility class and ground type. Significant correlation appears only with variation in seismic intensity, which is expressed as peak ground acceleration and spectral acceleration. The seismic intensity being fixed, as peak ground acceleration is in the code check, the correlation is too weak to predict the drift demands of an infilled frame from those of its bare counterpart. The null hypothesis of statistical independence of the drifts of the bare and infilled frames cannot be rejected at usual significance levels. The results contradict the code assumption. Modelling the non-structural masonry infills to compute the drift demand should be required in building codes. [ABSTRACT FROM AUTHOR]

This article deals with the production of veneer walls as specified in DIN EN 1996-2/NA [3]. Against this background of the extensive revision of the section for veneer walls an exposition in accordance with the previous requirements as specified in DIN 1053-1 can hardly be recommended. The necessity for a basic revision of the section for veneer wall construction has already been discussed in detail and justified in several technical articles published in previous years, see [4] to [7]. With many changes and corrections in the section for veneer walls in the National Annex of DIN EN 1996-2 [8] it is certainly not a question of new rules for this method of building, but an adjustment of the requirements in the previous standard on the basis of the practical experience gained over several years. The new requirements for the execution of cavity facing masonry enable a simple and economic implementation of this external wall construction. [ABSTRACT FROM AUTHOR]

In the recent past, the masonry industry has developed many different solutions for optimising the heat protection of buildings. This took place for the building materials, geometric design, but also by development of multiple layered stones in which the components masonry unit, insulation and outer shell have been integrated into a block. [ABSTRACT FROM AUTHOR]

Building with factory-prefabricated masonry panels made of clay units meanwhile has become a long-established, field-proven construction method. The advantages are shorter construction time for shell constructions, lower construction costs and uniform level of quality as well as high dimensional accuracy of the masonry panels and a production that is independent of weather influences. An innovation in the field of prefabricated masonry is the dry bonding method for prefabricated masonry panels made of clay units whereby, instead of a conventional thin layer mortar, a two-component polyurethane adhesive (2C-PUR) is applied by machine to the flat ground surface of the clay unit. In mid 2013, the Institute of Building Materials Research (ibac) in Aachen was commissioned by Redbloc Deutschland GmbH to carry out tests on masonry prefabricated with 2C-PUR adhesive, to establish the necessary basis for obtaining a general technical approval (abZ) for masonry panels built according to the Redbloc system and thereby lay the foundations for using this new construction method in Germany. This article shall firstly give a survey of the test programme for the approval procedure agreed with the German building authority , Deutsches Institut für Bautechnik (DIBt), and present the key results obtained from the tests carried out in Aachen. Furthermore the individual steps from planning via production in the prefabrication plant right through to transport and assembling of the masonry panels at the building site will be presented, taking the example of the first prefabrication factory of Redbloc Elemente GmbH opened at Plattling in Germany in the meantime. [ABSTRACT FROM AUTHOR]

The article presents a study that determines the dynamic behaviour of the unreinforced masonry (URM) with roof slab as an integral system. Discussion on the method of the study that examines the natural frequency of single stories box-type masonry buildings with and without roof slab is provided. The result of the study which indicates the factors that caused the excessive cracking, buckling of wall, and falling down of wall of the building is offered.

The test results of nine confined masonry wall specimens, with three different connection details between the masonry and the tie-columns and one unreinforced masonry wall, are presented. The specimens were executed and were tested under constant vertical and cyclic lateral loads. Failure modes, hysteresis loops, resistance envelope curves, averaged evaluated bilinear response envelope curves and behaviour factors were all obtained. Confinement brought an increase in the stiffness, lateral load capacity, ductility and hysteretic energy dissipation of the walls. The connection details did not influence the initial stiffness or the maximum lateral resistance, but they did improve the nonlinear wall behaviour, behaviour factors and hysteretic energy dissipation. They also helped in activating the whole wall for lateral load resistance and maintained its composite behaviour well into the nonlinear range. The measured behaviour factors of all the specimens were above the values suggested by the Eurocodes. The analytical expressions available differed from the prediction quality of the measured results. [ABSTRACT FROM AUTHOR]

This study presents some numerical results related to the analysis of the structural damage of a historic masonry building, Palazzo Gulinelli, in Ferrara, Italy. A detailed analysis of the inhomogeneities of the facade, historic documentation, and recent restoration interventions carried out in an adjacent building, suggest that the Palace underwent various modifications both on the structural configuration and on the borne loads. Such modifications might be the main cause of some differential settlements and of the consequent significant crack pattern on the load-bearing walls. Therefore, in the present paper the occurrence of a crack pattern on the facade is simulated by carrying out standard linear and non-linear finite element (FE) homogenized models; differential settlements are applied in order to reproduce the structural changes occurred over time. Previous experiences of the authors (for example, Acito and Milani in 2012 and Mallardo et al. in 2008), the current crack pattern of the building (of its facade in particular) and the monitoring data referring to some of them are the main references for the analysis carried out. The structural survey, the numerical results, and the data monitoring suggest two main conclusions: 1) a good correlation between numerical results and monitoring data is assessed, therefore the cracks can be reasonably related to past differential settlements; and 2) the cracks/damage that occurred as a consequence of differential foundation settlements reduce the ability of the facade to resist seismic actions. [ABSTRACT FROM PUBLISHER]

Studies concerned with evaluation and rehabilitation of historical masonry towers consider in situ investigations and structural analysis in order to better understand the seismic behaviour of these buildings, to define the causes for present damage and to asses the safety level for a large variety of actions. These pages follows, in the case of a historic masonry bell-tower structure, a description of the on site and laboratory investigations correlated with finite element models. Also, a proper retrofitting solution is presented. Advantages and disavantages of different modelling techniques, calibration of finite element models with ambient vibrations tests and the applicability of these methods in the field of old masonry structures assessment are presented. [ABSTRACT FROM AUTHOR]

Originally, brick/block was formed by placing moist clay/cement mortar in a mold by hand. As modern industrial methods were implemented in the cement block manufacturing process, the majority of production was changed from a molded process to an extrusion process. Extrusion more easily accommodates the inclusion of hollow (void area) in a block unit, which in turn can make the manufacture and use of block more cost-effective and material efficient. Although void area in block varies from place to place, hollow masonry unit standards are defined by ASTM C90-11b, and specifications are related to the minimum face shells and a web requirement. This paper examines the effect of the void area on aspects of the performance of hollow cement block masonry. The performance of five comparison sets of hollow cement masonry was evaluated for different range of void area. Water absorption, compressive strength of cement block, compressive, shear, and flexural tensile strength of masonry prism were measured on each type of hollow block and used as indicators of potential performance in a masonry wall. [ABSTRACT FROM AUTHOR]

The bond behavior between FRP composites and masonry substrate plays an important role in the performance of externally bonded reinforced masonry structures. Therefore, monitoring the bond quality during the application and subsequent service life of a structure is of crucial importance for execution control and structural health monitoring. The bond quality can change during the service life of the structure due to environmental conditions. Local detachments may occur at the FRP/substrate interface, affecting the bond performance to a large extent. Therefore, the use of expedite and efficient non-destructive techniques for assessment of the bond quality and monitoring FRP delamination is of much interest. Active infrared thermography (IR) technique was used in this study for assessing the bond quality in environmentally degraded FRP-strengthened masonry elements. The applicability and accuracy of the adopted method was initially validated by localization and size quantification of artificially embedded defects in FRP-strengthened brick specimens. Then, the method was used for investigating the appearance and progression of FRP delaminations due to environmental conditions. GFRP-strengthened brick specimens were exposed to accelerated hygrothermal ageing tests and inspected periodically with the IR camera. The results showed environmental exposure may produce large progressive FRP delaminations. [ABSTRACT FROM AUTHOR]

The use of unreinforced masonry (URM) walls is common practice in different types of construction, such as interior or exterior walls. URM walls are typically deficient in flexural capacity when subjected to out-of-plane loading caused by high wind pressure or earthquakes. Retrofitting masonry walls with novel materials, such as fiber-reinforced polymer (FRP) composites, has shown enhancement of the flexural capacity and pseudoductility. This study evaluates the feasibility of fabric-reinforced cementitious matrix (FRCM) as an alternative external strengthening technology to improve out-of-plane behavior of URM walls. This paper reports experimental results on flexural capacity of nine clay brick walls of which six were strengthened with two different amounts of FRCM, namely one and four reinforcement fabrics. Experimental evidence shows significant improvements in the structural performance in terms of flexural capacity and stiffness of the strengthened walls. An analysis, disregarding arching effect, is conducted, and its results are compared with the experimental database. From here, the design limits are discussed. Finally, experimental data from other research programs using FRP are reported to show that when flexural capacity is related to a calibrated reinforcement ratio, the two technologies are equivalent. [ABSTRACT FROM AUTHOR]

Timber-framed wall buildings are seen all over Europe, especially in seismic regions, given its adequacy to resist earthquakes. The pombaline buildings, developed after the big 1755 earthquake that destroyed Lisbon, constitute one of the best examples of ancient seismic-resistant structures based on timber-framed masonry walls. But in addition to suffering natural degradation and frequent inadequate interventions, these buildings were not prepared to resist the severe seismic actions envisaged by today's structural codes. In this context, they increasingly have to undergo rehabilitation and reinforcing works. The success of these projects strongly depends on the accuracy of the structural modelling, which in turn depends on knowledge of the behaviour of the existing structure. Aiming at providing reliable data to be used in structural design, a series of tests was carried out on the base element that constitutes the timber-framed masonry walls: the Saint Andrew's cross. The experimental tests were numerically simulated in order to determine the parameters that lead to the most accurate results when using linear-elastic models. [ABSTRACT FROM AUTHOR]

The seismic resistance characteristics of two building models constructed by Hollow Compressed Stabilized Earth Block from locally available soil that represents normal single room building was examined via the experimental studies in the shake table. One model was constructed with earthquake-resistant features (EQRF) having sill band, lintel band and vertical bands to control the building vibration, and another one was without EQRF. The model with EQRF provides superior seismic resistance as compared with that model without EQRF. To examine the seismic capacity, the models were subjected to harmonic acceleration with gradually increasing amplitude, and specimens were shaken repeatedly until its failure. The test results from Hi-end Data Acquisition system show that model with EQRF behaves better than without EQRF. This modified masonry model with new material combined with band system is used to improve the behavior of masonry building. [ABSTRACT FROM AUTHOR]

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Abstract: Tripod bucket foundations are being used as alternative foundations to resist large horizontal and moment loadings from offshore wind turbines. The bearing capacity of the tripod bucket foundation differs particularly from that of the single bucket foundation due to the interaction among individual buckets of the tripod. This paper investigated the group effect of tripod bucket foundations in clay by three-dimensional finite element analysis. Parametric studies were performed varying the spacing between each bucket foundation, embedded depth of the bucket foundation, and loading directions. Normally consolidated clay under an undrained condition was modeled using a linear elastic-perfectly plastic model obeying the Tresca failure criterion. The undrained shear strength and Young's modulus of clay were assumed to linearly increase with depth. The group efficiency factor, which is the ratio of the bearing capacity of the tripod bucket foundation to that of the single bucket foundation, was evaluated based on finite element analysis for vertical, horizontal and moment loadings. Results showed that the efficiency factors were functions of the bucket spacing and embedment depth of the foundations. [Copyright &y& Elsevier]

SUMMARY The macroelement technique for modelling the nonlinear response of masonry panels is particularly efficient and suitable for the analysis of the seismic behaviour of complex walls and buildings. The paper presents a macroelement model specifically developed for simulating the cyclic in-plane response of masonry walls, with possible applications in nonlinear static and dynamic analysis of masonry structures. The model, starting from a previously developed macroelement model, has been refined in the representation of flexural-rocking and shear damage modes, and it is capable of fairly simulating the experimental response of cyclic tests performed on masonry piers. By means of two internal degrees of freedom, the two-node macroelement permits to represent the coupling of axial and flexural response as well as the interaction of shear and flexural damage. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Studies concerned with evaluation and rehabilitation of historical masonry structures consider structural analysis in order to better understand the seismic behaviour of these buildings, to define the causes for present damage and to asses the safety level for a large variety of actions. Structural analysis such as linear, plastic or nonlinear analysis contributes to all the stages and activites related to the evaluation and rehabilitation process. This paper follows a description of the modelling methods of masonry structures taking into consideration different modelling strategies in correlation with the complexity of the analysed elements and the expected type of results. Advantages and disavantages of different modelling techniques and the applicability of these methods in the field of old masonry structures assessment are presented. [ABSTRACT FROM AUTHOR]

We present a novel approach for the analysis and design of self-supporting simplicial masonry structures. A finite-dimensional formulation of their compressive stress field is derived, offering a new interpretation of thrust networks through numerical homogenization theory. We further leverage geometric properties of the resulting force diagram to identify a set of reduced coordinates characterizing the equilibrium of simplicial masonry. We finally derive computational form-finding tools that improve over previous work in efficiency, accuracy, and scalability. [ABSTRACT FROM AUTHOR]

Für die Analyse gemauerter Bogentragwerke aus Natursteinen ist ein umfassender Kenntnisstand des Bestandes erforderlich. Das bedarf einer strukturierten Zusammenarbeit aller Fachdisziplinen, die sich mit der Erkundung und Beurteilung von Natursteinbauwerk beschäftigen. Bei der statischen Analyse sind die im 19. Jahrhundert entwickelten grafischen Verfahren hilfreich. Ihre Ergebnisse dienen als Eingangsgröße für elektronisch gestützte Modelle und deren Plausibilitätskontrolle. Aufgrund der potentiellen Kinematik von gemauerten Bogentragwerken kann ihre Traglast nur nichtlinear, also ohne Superposition der Lastfallergebnisse, ermittelt werden. Ist eine Stabilisierung eines gemauerten Bogentragwerks unumgänglich, so sollte ein biegesteifer Überbau in Betracht gezogen werden. Die Verstärkung von Bögen mit einer aufbetonierten Schale sollte vermieden werden. Retrofitting of masonry arch structures under high loads. For the analysis of masonry arch structures made of natural stone, a comprehensive knowledge of the existing structure is required. It needs a structured cooperation between all scientific disciplines that deal with the exploration and evaluation of natural stone buildings. The graphic methods developed in the 19th Century, are helpful. The results will serve as input for electronically supported models and their validation. Because of the potential kinematics of masonry arch structures, the collapse load can only be determined non-linear, which means without superposition of the load case results. If a stabilisation of a masonry arch structure is inevitable, a more rigid superstructure should be considered. It should be avoided to reinforce the arch structure with a skin of ferroconcrete. [ABSTRACT FROM AUTHOR]

The present paper presents a comparative study about confined masonry buildings (having the same current story plan, but different heights) in interaction with the foundation bearing soil. The buildings are composed of basement, ground floor and 2 to 4 floors above the ground floor; the number and dimension of the bays on both directions are given in the architectural current story map. The efforts and displacements in the structural elements are evaluated using gravity and seismic loads, from seismic coefficients, acceleration diagrams and spectrums, in interaction with the soil. The article compares the effects on the foundation bearing soil, the efforts (σx, σz, τyz, τxy) and settlements (Δ) from all 3 structures; the soil is calculated by 3D models. Moreover, using 3D models, the behavior of structures in interaction with the soil is presented: the displacements (on the tree orthogonal directions) due to seismic loading, the vibration periods (for the superstructure modeled with basement, foundations and soil), and the increasing efforts in the soil, as the number of stories grows (as 2D models on both the transversal and longitudinal directions that include both structure and soil) [ABSTRACT FROM AUTHOR]

An analysis of soil-structure interaction of a construction with unsatisfactory foundation behavior along time is presented. Previous analyses by Rosa (2005) are briefly described considering soil x structure interaction in predicting foundation settlement. In addition, a new analysis is now presented, including the influence of the masonry in the soil-structure interaction. The predicted distortional settlements are analyzed in conformity with the observed damages documented at various moments of the construction lifetime. Kelvin's model was employed to represent the soil behavior along time. Notwithstanding the simplifications adopted and justified in the article, the results of the numerical analysis were able to reproduce the extent and spatial location of the damages. Such results show the relevance of a more realistic foundation analysis involving soil x structure interaction. [ABSTRACT FROM AUTHOR]

Abstract: The main reason of the collapsible diseases of masonry structure in the loess regions is the foundation soil soaked by water. Based on the survey of the collapsible disease of masonry structure in the loess regions, by analyzing the reasons for the occurrence of collapsible disease, the paper proposed the measures for preventing the collapsible disease of masonry structure in design, construction and use stage, and the treatment measures if the collapsible disease occurred according to the characteristics of loess and the masonry structure. Thus a reference for the prevention and treatment of the collapsible disease of masonry structure in the loess regions is provided. [Copyright &y& Elsevier]

In this article, the Interzone Temperature Profile Estimation solutions are first utilized to carry out a frequency analysis for the foundation heat transfer to determine the effect of indoor air and ambient air temperature fluctuations on the variation of the foundation heat loss/gain. Then, a frequency-domain regression-based method is used to develop transfer functions for ground-coupled surfaces. The regression frequency-domain method is tested and validated using one-dimensional heat transfer for above-grade walls. It is found that the proposed method provides a more effective alternative than numerical methods to estimate conduction transfer function coefficients for building foundations and thus can be easily implemented in whole-building simulation programs. [ABSTRACT FROM AUTHOR]

Stone masonry is one of the oldest building techniques used worldwide and it is known to exhibit poor behaviour under seismic excitations. In this context, this work aims at assessing the in-plane behaviour of an existing double-leaf stone masonry pier by experimental testing. Additionally, a detailed 3D finite element numerical analysis based on micro-modelling of the original pier is presented (fully describing the geometry and division of each individual elements, namely infill, blocks and joints) aiming at simulating the experimental test results. This numerical strategy can be seen as an alternative way of analysing this type of constructions, particularly useful for laboratory studies, and suitable for the calibration of simplified numerical models. As part of a wider research activity, this work is further complemented with the presentation of an effective retrofit/strengthening technique (reinforced connected plaster) to achieve a significant improvement of its in-plane cyclic response which is experimentally verified in the results presented herein. [ABSTRACT FROM AUTHOR]