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Item type:Publication, Numerical simulation of an adobe wall under in-plane loading(2014)Adobe is one of the oldest construction materials that is still used in many seismic countries, and different construction techniques are found around the world. The adobe material is characterized as a brittle material; it has acceptable compression strength but it has poor performance under tensile and shear loading conditions. Numerical modelling is an alternative approach for studying the nonlinear behaviour of masonry structures such as adobe. The lack of a comprehensive experimental database on the adobe material properties motivated the study developed here. A set of a reference material parameters for the adobe were obtained from a calibration of numerical models based on a quasi-static cyclic in-plane test on full-scale adobe wall representative of the typical Peruvian adobe constructions. The numerical modelling, within the micro and macro modelling approach, lead to a good prediction of the in-plane seismic capacity and of the damage evolution in the adobe wall considered. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Rope mesh as a seismic reinforcement for two‑storey adobe Buildings(2022)Throughout the world, millions of people are at risk because they live in unreinforced earthen dwellings, which have consistently shown extremely poor structural behaviour during earthquakes. Every single earthquake occurring in these areas has caused unacceptable loss of life, injuries, and property damage. Earthquakes are recurrent and construction damage is cumulative. It is urgent, therefore, to devise low-cost, easy-to-implement seismic reinforcement systems and to make them available to the actual dwellers. A group of researchers at the Pontificia Universidad Católica del Perú has been working towards that goal, especially on improving the seismic capacity of one-storey adobe dwellings. They have proposed construction methodologies for a seismic reinforcement system consisting of a mesh of nylon ropes that confines all earthen walls. This reinforcement system would control the wall displacements and prevent the overturning of wall portions that may occur due to seismic shaking. To validate the effectiveness of the nylon rope mesh reinforcement on two-storey adobe dwellings, shaking table tests were conducted on unreinforced and half-scale reinforced adobe models, simulating the actions of slight, moderate and strong seismic ground shaking. These models were designed to include the main construction features of typical adobe dwellings in the Peruvian Andes. The results of the experimental tests showed that the rope mesh reinforcement system was able to preserve the structural stability of the tested reduced-scale adobe models under strong motions, thus preventing collapse. It is expected that the proposed reinforced system would also improve the seismic performance of one and two-storey adobe dwellings, reducing in this way their inherent high seismic risk. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Mechanical characterization of adobe masonry(Springer Nature, 2021-01-01)The characterization of the mechanical properties and behaviour of adobe masonry is fundamental for the understanding of the structural behaviour of adobe constructions. Thus, in the last decades, experimental studies focused on this topic have been carried out by different authors. Many of the existing experimental works, however, were carried out aiming to support broader studies focused on the seismic behaviour of adobe constructions and are not very detailed. Moreover, authors tend to adopt different procedures in their experimental work, since there are few indications in existing standards for testing adobe masonry. The wide variety in materials used, both for the adobes and mortars, further complicates this work, making it difficult to compare results obtained in different studies. This chapter provides an overview of the indications given by standards and other technical recommendations for the mechanical testing of adobe masonry. It presents a review of existing research on the mechanical behaviour of adobe masonry, addressing studies that focus on: (i) compression behaviour, (ii) shear behaviour, (iii) joint shear behaviour. It provides a global analysis of the existing knowledge, suggesting improvements for normative documents and identifying future research needs. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Mechanical characterization of adobe bricks(Springer Nature, 2021-01-01)The mechanical characterization of adobe bricks is an important first step in the study of the behaviour of adobe masonry. For this reason, in the last decades, different authors have conducted research on the mechanical behaviour of adobes from various regions of the world. Despite the importance of mechanical characterization, there are still only a few standards and normative documents with clear indications for the mechanical testing of earthen materials and, in general, these indications are not thorough and vary among different countries. Consequently, authors tend to adopt different types of test specimens and procedures in their experimental work, thus obtaining results that are not directly comparable. The fact that the materials and procedures traditionally used are also not standardized, varying greatly from region to region, also contributes to the difficulty of comparing results from different studies. This chapter presents a review of the indications provided by codes, standards and other technical recommendations for the mechanical testing of adobe bricks, as well as a detailed review of procedures adopted, and results obtained by different authors regarding the mechanical characterization of traditional adobe bricks. This chapter focuses, in particular, on the behaviour of adobe bricks when subjected to simple compression. It provides an overview of the existing knowledge and identifies needs for future research and development. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Numerical modelling of adobe structures(Springer Nature, 2021-01-01)Numerical assessment of adobe structures allow several drawbacks of experimental testing to be overcome, either to carry out back-analyses or to predict the seismic performance of real constructions. Among a number of modelling strategies, this chapter presents the main features of the finite element method, discrete element method and equivalent frame method, discussing their implementation in the case of adobe constructions. Pros and cons of each modelling approach are identified in view of real-world applications. Recent developments are discussed and research needs are detected for future studies. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Seismic strengthening techniques for adobe construction(Springer Nature, 2021-01-01)Heavy damage to adobe constructions observed after earthquakes, experimental programmes and numerical simulations have demonstrated high vulnerability levels that require appropriate strengthening measures. Given that a large fraction of adobe constructions are located in less developed countries, there is a need for effective strengthening techniques that are low-cost and easy to install at the same time. In this chapter, a comprehensive selection of research studies is critically reviewed to provide useful information to researchers and professionals involved in the conservation and retrofit of adobe constructions. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Shaking table testing of adobe masonry structures(Springer Nature, 2021-01-01)This chapter presents the seismic simulation systems (shaking tables) as essential resources for experimental research on adobe masonry structures. An overview of selected relevant shaking tables existing in laboratories around the world gives an idea of the broad testing scope possible with this type of equipment. Its use in testing of adobe masonry structures goes back to 1986 at the University of California at Berkeley and to 1988 at the Pontifical Catholic University of Peru (PUCP). Shaking table testing has been considered the experimental technique that may closest reproduce the real behaviour of an adobe structure during earthquakes. After the description of a typical shaking table test procedure, based on more than thirty years of PUCP experience, some seismic simulation tests on adobe masonry structures performed in different countries are briefly described. Each case presents the basic characteristics of the shaking table and some qualitative results obtained to understand the seismic behaviour of adobe masonry structures. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Research developments and needs on seismic performance and strengthening of adobe masonry constructions(Springer Nature, 2021-01-01)The significant amount of studies on adobe masonry constructions, which have received growing interest from researchers and practitioners, allows preliminary conclusions on the state-of-the-art to be drawn. Besides, several research needs can be delineated to create the basis for knowledge development and implementation of seismic risk mitigation programmes. Past studies moved from material characterization to structural performance assessment through numerical simulation and experimental testing, as well as seismic strengthening. Future lines of research could focus on test standardisation, non-destructive and minor-destructive testing, full-scale testing to support structural modelling and strengthening, and numerical simulation through discrete element and equivalent frame methods. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Behaviour of adobe construction in recent earthquakes(Springer Nature, 2021-01-01)The adobe masonry is classified as a quasi-brittle material. This is because the material fails under very low tensile stresses. Then, under the action of any type of loading (especially dynamic one), adobe masonry behaviour rapidly changes into nonlinear behaviour. However, adobe masonry resists moderate compressional loading. During earthquake actions, the adobe material starts to fail at the zones of stress concentration, such as corners of openings. Also, vertical cracks at the intersection of two orthogonal walls may appear. This is due to the absence of confinement elements that could guarantee a box behaviour on each floor. If walls continue breaking, then the most probable failure is due to the overturning of walls and the roof collapse. In this chapter, the most common types of failure of adobe buildings are shown and discussed based on field surveys carried out after some earthquakes. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Integration of non-destructive testing, numerical simulations, and simplified analytical tools for assessing the structural performance of historical adobe buildings(Elsevier, 2021-07-05)For existing structures, the development of seismic vulnerability studies requires the availability of information related to geometry, boundary conditions, material properties, and accumulated damage. In the case of historical constructions, modern conservation criteria recommend carrying out a comprehensive structural assessment that involves the use of concurrent experimental diagnosis complemented with numerical and analytical approaches for structural analysis. This paper presents a proposal for a comprehensive integration of these perspectives by the application of several tools for the seismic performance analysis of an iconic Andean historical adobe building: the 'San Pedro Apostol Church' located in Andahuaylillas, Southern Peru. In this church, several non-destructive techniques for geometrical and damage assessment were combined with structural exploration tools, nonlinear numerical modeling, and simplified analytical tools for performing predictive seismic analysis. The results indicate the feasibility of the integration of these techniques for studying existing earthen buildings and their capacity to properly predict observed damage in past earthquakes (i.e. failures of bell towers, façade walls, tympani, and triumphal arches). In particular, the analyses allowed the identification of high seismic vulnerability of the studied church in occasional earthquakes (earthquakes with a return period of 72 years) due to the activation of collapse mechanisms consisting of rocking of the façade walls and out-of-plane overturning of the lateral walls.