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URI permanente para esta colecciónhttp://54.81.141.168/handle/123456789/124168
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Ítem Desconocido Out-of-plane analysis of dry-stone walls using a pseudo-static experimental and numerical approach in scaled-down specimens(Elsevier, 2021) Santa-Cruz, Sandra; Daudon, Dominique; Tarque, Nicola; Zanelli, Criss; Alcántara, JulioThe objective of the present work is to study the response of dry stone walls subjected to out-of-plane forces and the influence of block`s rugosity, joint arrangement, and border conditions. For this purpose, a series of scaled-down experimental tests on a tilting table and 3D numerical modelling using discrete elements, DEM, are proposed. In the numerical model, the applicability of some types of discrete elements is first studied. The preliminary analysis gives us useful information about the effects of the joint disposition and the border conditions in the response. Finally, the sensitivity of the response of the blocks to the parameter’s variations is analyzed. The experimental and numerical results show that the DEM method is adequate to simulate the failure mode, the displacement, and the lateral load of stone walls due to out-of-plane lateral loads considering the effect of the irregularity of the blocks, joint arrangement, and border conditions.Ítem Acceso Abierto Experimental assessment of confined masonry walls retrofitted with SRG under lateral cyclic loads(2019) Yacilaa, Jhair; Salsavilcaa, Jhoselyn; Tarquea, Nicola; Camatab, GuidoAround the world, many informal masonry buildings have collapsed due to the failure of their bearing walls under lateral seismic loads. This is related to the many involved factors, such the quality of the materials, the quality of workmanship, the lack of technical intervention, and the high seismicity of the zone, among others. However, the fact is that these constructions need to be retrofitted in order to upgrade their ultimate strength and allow them to properly absorb inelastic deformations. Currently, fiber reinforced polymer (FRP) has been widely studied as a retrofitting technique. However, it has some technical and economic disadvantages that are remedied by fiber reinforced mortar (FRM). In this paper, a variant of FRM known as steel reinforced grout (SRG) is studied as a seismic retrofitting technique for cracked confined masonry walls (CMW). For this purpose, three full-scale cracked walls were repaired, retrofitted with SRG strips, and tested under in-plane cyclic loads at the Pontifical Catholic University of Peru (PUCP). The experimental results show the benefits of SRG in improving the lateral displacement ductility, energy dissipation, and stiffness degradation of CMWs.Ítem Acceso Abierto Multi-criteria analysis of five reinforcement options for Peruvian confined masonry walls(2019) Tarque, Nicola; Salsavilca, Jhoselyn; Yacila, Jhair; Camata, GuidoIn Peru, construction of dwellings using confined masonry walls (CM) has a high percentage of acceptance within many sectors of the population. It is estimated that only in Lima, 80% of the constructions use CM and at least 70% of these are informal constructions. This mean that they are built without proper technical advice and generally have a high seismic vulnerability. One way to reduce this vulnerability is by reinforcing the walls. However, despite the existence of some reinforcement methods in the market, not all of them can be applied massively because there are other parameters to take into account, as economical, criteria for seismic improvement, reinforcement ratio, etc. Therefore, in this paper the feasibility of using five reinforcement techniques has been studied and compared. These reinforcements are: welded mesh (WM), glass fiber reinforced polymer (GFRP), carbon fiber reinforced polymer (CFRP), steel bar wire mesh (CSM), steel reinforced grout (SRG). The Multi-Criteria Decision Making (MCDM) method can be useful to evaluate the most optimal strengthening technique for a fast, effective and massive use plan in Peru. The results of using MCDM with 10 criteria indicate that the Carbon Fiber Reinforced Polymer (CFRP) and Steel Reinforced Grout (SRG) methods are the most suitable for a massive reinforcement application in Lima.Ítem Desconocido Building constructions characteristics and mechanical properties of confined masonry walls in San Miguel (Puno-Peru)(2022) Tarque, Nicola; Pancca-Calsin, ErikaHouse self-construction and self-management are very common in different cities in Peru, which is the case in several areas in the district of San Miguel (Puno). This is due to the lack of financial resources to hire professionals to design and construct their houses. Therefore, many residents build without technical guidance and materials without quality standards. As a result, the buildings in the area have various construction pathologies that demonstrate their high seismic vulnerability, which indicates that the guidelines established in the Peruvian Masonry Design Code NTE 070 are not followed. Therefore, as a first step towards evaluating the seismic vulnerability of the houses in San Miguel, it was decided to evaluate the construction pathologies and typologies by conducting a survey. Subsequently, to characterize and evaluate the physical-mechanical properties of the masonry walls, 24 piles and 24 small walls were built and tested. The materials tested were obtained from the urban area of the same study place. According to the experimental tests, it was observed that the axial compression and diagonal shear values of the prisms are lower than the minimum values specified in the Peruvian Construction Code, and this would increase the seismic vulnerability of the constructions. Therefore, many of the houses in the district could suffer significant damage and even collapse in a seismic event.Ítem Desconocido Development of fragility curves for confined masonry buildings in Lima, Peru(2018) Lovon, Holger; Tarque, Nicola; Silva, Vitor; Yepes-Estrada, CatalinaThis paper aims at investigating the seismic fragility of confined masonry (CM) structures in Lima, Peru, which can be used to perform earthquake scenarios at urban scale. A database describing the geometric properties (walls density, building area, height) of this type of structure was developed using data from field surveys. This information was complemented with results from experimental tests to compute a large set of capacity curves using a mechanical procedure. These models were tested against a set of ground motion records using the displacement-based earthquake loss assessment (DBELA) procedure, and the structural responses were used to derive fragility functions for four building classes. The resulting fragility curves were convoluted with seismic hazard curves to evaluate the annualized expected loss ratio and annual collapse probability.Ítem Acceso Abierto Rope mesh as a seismic reinforcement for two‑storey adobe Buildings(2022) Tarque, Nicola; Blondet, Marcial; Vargas‑Neumann, Julio; Yallico‑Luque, RamiroThroughout 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.Ítem Acceso Abierto Masonry infilled frame structures: state-of-the-art review of numerical modelling(2015) Tarque, Nicola; Candido, Leandro; Camata, Guido; Spacone, EnricoThis paper presents a state-of-the-art review of the nonlinear modelling techniques available today for describing the structural behaviour of masonry infills and their interaction with frame structures subjected to in-plane loads. Following brief overviews on the behaviour of masonry-infilled frames and on the results of salient experimental tests, three modelling approaches are discussed in more detail: the micro, the meso and the macro approaches. The first model considers each of the infilled frame elements as separate: brick units, mortar, concrete and steel reinforcement; while the second approach treats the masonry infill as a continuum. The paper focuses on the third approach, which combines frame elements for the beams and columns with one or more equivalent struts for the infill panel. Due to its relative simplicity and computational speed, the macro model technique is more widely used today, though not all proposed models capture the main effects of the frame-infill interaction.Ítem Acceso Abierto Expected Ground Motion at the Historical Site of Poggio Picenze, Central Italy, with reference to current Italian Building Code(2013) Tarque, N.; Lai, C. G.; Bozzoni, F.; Miccadei, E.; Piacentini, T.; Camata, G.; Spacone, E.The amplification of the ground motion at the surface is greatly influenced by the geotechnical characteristics of the soil formations below the ground surface. Traditionally, analyses of the ground response are deterministic, which means no consideration of the aleatory nature of geotechnical parameters of soil layers like density, shear wave velocity, etc. A fully stochastic procedure for estimating the site amplification of ground motion allows taking into account the record-to-record variability in an input ground motion and the uncertainty in dynamic soil properties and in the definition of the soil model. In particular, their effect on response spectra at the ground surface can be evaluated. With this procedure, it is pretended to reduce the aleatory variability into the soil model. In this work, the soil profile below the San Felice Martire church, at Poggio Picenze (L’Aquila area, Abruzzo, Central Italy), has been studied basically on field geologic observations and drilling and geophysical tests retrieved from previous investigation campaigns. The dynamic soil properties were obtained by literature and by the test results. Amplification effects at the site under investigation have been estimated using fully 1D stochastic site response analyses and for the object motion 7 real records compatible to the Italian code-based spectrum referred to 475-year return period. The Italian building code defines the reference seismic action in terms of elastic acceleration response spectra derived from the results of a probabilistic seismic hazard study. The results in terms of accelerograms and acceleration response spectrum (with the associated dispersion) indicated a clear amplification of the input motion at the basement of San Felice Martire church due to the lithostratigraphic characteristics of the soil deposits at the site under investigation.Ítem Acceso Abierto Alternative approach for reproducing the in-plane behaviour of rubble stone walls(2017) Tarque, Nicola; Camata, Guido; Benedetti, Andrea; Spacone, EnricoStone masonry is one of the oldest construction types due to the natural and free availability of stones and the relatively easy construction. Since stone masonry is brittle, it is also very vulnerable and in the case of earthquakes damage, collapses and causalities are very likely to occur, as it has been seen during the last Italian earthquake in Amatrice in 2016. In the recent years, some researchers have performed experimental tests to improve the knowledge of the behaviour of stone masonry. Concurrently, there is the need to reproduce the seismic behaviour of these structures by numerical approaches, also in consideration of the high cost of experimental tests. In this work, an alternative simplified procedure to numerically reproduce the diagonal compression and shear compression tests on a rubble stone masonry is proposed within the finite element method. The proposed procedure represents the stone units as rigid bodies and the mortar as a plastic material with compression and tension inelastic behaviour calibrated based on parametric studies. The validation of the proposed model was verified by comparison with experimental data. The advantage of this simplified methodology is the use of a limited number of degrees of freedom which allows the reduction of the computational time, which leaves the possibility to carry out parametric studies that consider different wall configurations.Ítem Acceso Abierto Nonlinear Dynamic Analysis of a Full-Scale Unreinforced Adobe Model(2014) Tarque, Nicola; Camata, Guido; Spacone, Enrico; Varum, Humberto; Blondet, MarcialThis paper describes the results of a numerical study of a full-scale adobe building model tested on a shaking table. Material properties of adobe masonry were calibrated to represent the wall in-plane seismic behavior, based on a prior numerical analysis of an adobe wall carried out by the authors. The inelastic part of the constitutive model was represented by a softening curve in tension and by a hardening/softening behavior in compression; thus, the fracture energy is a key issue in the modeling process. A finite element model that relies on a homogenous continuum approach was developed in Abaqus/Explicit software. The damage evolution in the numerical simulation represented fairly well the experimental crack pattern, for in-plane and out-of-plane seismic effects. Overall, the calibrated material properties and the explicit solution scheme proved to be appropriate for simulating the seismic behavior and predicting capacity of unreinforced adobe structures subjected to seismic loading.