The Improved Modal Pushover Analysis (IMPA) is a multimode procedure that has the advantage of redefining the lateral load applied, when comparing with the multimode current methods; hence, instead ...of considering the elastic deformed shape, it is possible to consider the deformed shape of the structure when it is behaving inelastically, as a pattern. The IMPA was proposed in the past and was successfully applied in the seismic assessment of bridges, the main objective of this work being to explore IMPA in buildings. For this purpose the seismic demands of two asymmetric plan buildings are herein estimated by means of IMPA and compared to Nonlinear Dynamic Analyses (NDA) and to current reference Nonlinear Static Procedures (NSPs): Modal Pushover Analysis (MPA) and two other NSPs that are proposed in American and European seismic codes (ASCE/SEI 41-06 NSP and N2 method respectively). In the latter, an extended version (extended N2) is considered, taking into account both the torsional and the higher mode effects.
The seismic response of the two buildings herein studied is obtained through two different approaches: the first regarding only one component of ground motion, while the second considers both components of ground motion acting simultaneously. The seismic assessment of both buildings is performed in terms of pushover curves, top displacement ratios, lateral displacements profiles, interstorey drifts, normalized top displacements and shear forces.
•An extension of IMPA is proposed for asymmetric plan buildings.•The individual performance of MPA, extended N2, ASCE41-06 NSP and IMPA was evaluated.•The NSPs were applied to two asymmetric plan buildings, and compared with NDA.•There is a general improvement with IMPA in relation to MPA.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Summary
The transcription factors ARABIDOPSIS THALIANA MERISTEM L1 (ATML1) and PROTODERMAL FACTOR2 (PDF2) are indispensable for epidermal cell‐fate specification in Arabidopsis embryos. However, the ...mechanisms of regulation of these genes, particularly their relationship with cell–cell signalling pathways, although the subject of considerable speculation, remain unclear. Here we demonstrate that the receptor kinase ARABIDOPSIS CRINKLY4 (ACR4) positively affects the expression of ATML1 and PDF2 in seedlings. In contrast, ATML1‐ and PDF2‐containing complexes directly and negatively affect both their own expression and that of ACR4. By modelling the resulting feedback loop, we demonstrate a network structure that is capable of maintaining robust epidermal cell identity post‐germination. We show that a second seed‐specific signalling pathway involving the subtilase ABNORMAL LEAFSHAPE1 (ALE1) and the receptor kinases GASSHO1 (GSO1) and GASSHO2 (GSO2) acts in parallel to the epidermal loop to control embryonic surface formation via an ATML1/PDF2‐independent pathway. Genetic interactions between components of this linear pathway and the epidermal loop suggest that an intact embryo surface is necessary for initiation and/or stabilization of the epidermal loop, specifically during early embryogenesis.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The use of nonlinear static procedures (NSPs) on the seismic assessment of real existing plan-irregular structures has so far been studied by a limited number of authors. This fact limits the ...application of such methods to assess current existing structures, the majority of which are irregular in plan. An extended version of the adaptive capacity spectrum method (ACSM) for the seismic assessment of plan-irregular buildings is presented in this paper. The novelty of this proposal is to comprise the most accurate features of commonly used NSPs in order to overcome the problems that subsist in three-dimensional pushover analyses. The accuracy of the procedure is tested in three plan-irregular real buildings. The results are compared with the capacity spectrum method (CSM) with the features proposed in FEMA 440, with the extended N2 method for plan-asymmetric structures, with the adaptive capacity spectrum method (ACSM) and with the most exact nonlinear dynamic analyses. Several seismic intensities are tested, in order to evaluate the performance of the procedure in different stages of structural inelasticity.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
•Failure analysis with advanced numerical FE computing on an outstanding historical palace.•Utilization of full 3D FE non-linear dynamic analyses to reproduce damage.•Comparison between non-linear ...static behaviour of a 3D model and equivalent frame.•Damage-plasticity with softening in tension and compression material used to model masonry.•N2 method to assess vulnerability after preliminary modal analysis.
The paper addresses the failure analysis under horizontal loads of the most ancient body of the National Palace of Sintra, Portugal: the Bonet building. This is a URM construction built on top of Arabic foundations during the reign of King Denis of Portugal around 1281; since then, few alterations have been made to the building. Due to the exemplary conservation of the whole palace, a few crack patterns are identified only on the top floor of the Bonet building, an area that is not open to visitors and that will soon undergo restoration works. The seismic vulnerability assessment of this building is carried out following two different approaches, enacted in two distinct numerical models: the so-called Equivalent Frame Method (EFM) and the Finite Element Method (FEM) developed in 3Muri and ABAQUS software, respectively. Both approaches adopt a numerical procedure based on the use of nonlinear static analyses, introducing “equivalent” boundary conditions that are defined to consider, approximately and conventionally, the possible interaction effects among the different parts of the structure. To minimize the multiple uncertainties usually existing in complex masonry buildings, whether related to geometry or masonry mechanical properties, a detailed structural survey is conducted through the laser scanning technology as well as in situ experimental tests. Different types of experimental tests are carried out, both non- and semi-destructive, including a Ground Penetrating Radar test, ambient vibration tests, flat-jack tests, and the collection of masonry samples. All these tests are important to adequately characterize the building and to calibrate the numerical models. Moreover, these tests enable the extraction of values for the mechanical properties of the rubble stone masonry that are used in the later numerical simulations on the Bonet building and, most importantly, can be used as a reference for future works regarding historical Portuguese monuments of the same period. Afterwards, the results obtained from the nonlinear static analyses with the two different software 3Muri and ABAQUS are presented and discussed. Specifically, the differences in modelling strategies and characterization of materials between the two software are considered with special regard to their feasibility, required computational effort, data availability and applicability to large scale structures. Efforts to calibrate and obtain the same behavior of the building for the different software are made, involving geometry, boundary conditions and characterization of the material constitutive laws. Eventually, a nonlinear dynamic analysis is carried out in ABAQUS to further assess the seismic vulnerability of the Bonet building; a spectrum-compatible accelerogram is applied to the numerical model, and the time-history of displacements in relevant control points of the buildings are extracted and discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•The in plane shear strength of rubble stone masonry walls is studied by means of experimental tests.•The cohesion of rubble stone masonry panels is assessed by diagonal compression tests.•The ...cohesion and the friction coefficient of rubble stone masonry panels are evaluated by triplet tests.•The obtained experimental results (shear strength parameters) are compared with other experimental works.
Rubble stone masonry walls were widely used in traditional buildings in Mediterranean countries. However, the mechanical behaviour of those walls is not completely characterized due to a lack of experimental data. This paper presents an experimental campaign carried out to characterize the shear strength parameters of traditional Mediterranean rubble stone masonry walls. Fifteen masonry specimens were built using old techniques and traditional materials. Two types of mortar were used in the specimens’ execution, air and hydraulic lime mortars, with intend to simulate different masonry construction periods. The goal of the experimental campaign was to evaluate the most important mechanical parameters needed for numerical modelling of traditional rubble stone masonry walls, namely, the compressive strength and Young’s modulus through compression tests; the cohesion and friction coefficient by triplet tests; and the diagonal tensile strength via diagonal compression tests. The tests’ setup and load–displacement diagrams are presented for all tests and the obtained shear strength parameters are compared with values from the literature.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The preservation and safeguarding of built cultural heritage is a permanent concern for institutions. These structures were generally poorly prepared for movement triggered by natural disasters, a ...situation further complicated in the case of earthquakes, as each building has a unique structural dynamic linked to its geometry, materials, method of construction and environmental conditions. The use of structural health monitoring (SHM) systems integrating monitoring techniques as well as inspection and structural analyses has gained great relevance in the appearance of low-cost IoT (Internet of Things) sensors on the market. In this paper, an IoT BIM-based solution is presented for real-time monitoring using low-cost sensors in the scope of building SHM systems. The case study takes place at the central body of the Palace of Monserrate, one of the most distinguished elements of the Cultural Landscape of Sintra. An H-BIM model was created in Autodesk Revit® software (version 2022 and 2023) based on a point cloud, and used as the basis for the numerical model developed in 3MURI. A MeM low-cost sensor was installed on the third floor of the central tower of the Monserrate Palace in Sintra, and the data gathered were recorded in the H-BIM model. The capacity to acquire real-time information on a structure’s vibration, both during normal operation and after an extraordinary occurrence, could allow the application of more effective maintenance and repair practices, resulting in lower operating costs and allowing for the best management of built cultural heritage.
The concepts of resistance to unforeseen disasters and rapid post-disaster recovery of historic cities are necessary due to the earthquakes that have profoundly influenced their evolution. The ...improvement of this property strongly depends on the effectiveness of the preventive tools. In this work, an operational framework for the resilience assessment of a historical city characterized by high cultural and historical elements is developed, which corresponds to the main contribution of this research. The research includes multicriteria analysis based on the in-depth knowledge of the city’s historical development, the study of the effects of past earthquakes, structural vulnerability analysis of pombalino buildings, architectural types and socio-economic aspects. The aim is to obtain the necessary elements to guide an aware plan for improving resilience and the reduction of vulnerability through a GIS tool aimed at preventing and defining urban intervention priorities. The framework proposed is applied to Lisbon downtown.
Building information modelling (BIM) has demonstrated its potential as a solution providing support to a series of operations related to facility management (FM) through building data retrieval, ...analysis, and processing. However, some challenges to the effective adoption of BIM-centred FM information systems occur in their design and implementation, causing obstacles to usability. Among these challenges are the customization of the information structure for each application case, the dynamic character of data supporting building maintenance, and the range of FM specialities involved, frequently including persons who are not BIM experts. This paper presents a BIM–FM prototype to support operations and access updated environmental data for a university building. The two contributions of the developed prototype are its ability to register two types of dynamic data, namely, the regularly acquired environmental sensor information and the sporadic building intervention records, and the automation of the data feeding, updating, and retrieval processes, allowing a user-friendly environment for both BIM experts and non-BIM users. Exploring the BIM interoperability and the integration of plug-ins, the proposed solution enables the comprehensive registration of dynamic FM-related data in an updated model while being accessible to all the specialities involved in the building management operations, enhancing its usability as an integrated solution for data maintenance and retrieval.
Mycotic aortic aneurysm: a ticking time-bomb Bento, Rita; Rodrigues, Gonçalo; Alves, Gonçalo ...
Angiologia e cirurgia vascular (Sociedade Portuguesa de Angiologia e Cirurgia Vascular),
05/2023, Volume:
19, Issue:
1
Journal Article
Peer reviewed
Open access
Abstract Introduction: Mycotic or primary infected aortic aneurysms comprise aproximately 1.3% of all aortic aneurysms and may be caused by septic emboli to the vasa vasorum, by haematogenous spread ...during bacteraemia or by direct extension of an adjacent infection leading to an infectious degeneration of the arterial wall and aneurysm formation. The objective of this report is to describe a clinical case of a complicated mycotic aortic aneurysm. Case report: A male, 69-year-old patient, with medical background of diabetes, hypertension and a bladder carcinoma (surgically ressected 5 years before, complicated at the time with an E.coli septicaemia), presented at the ER with generalised malaise, asthenia, anorexia, abdominal pain, diarrhea and fever, with 1 week of evolution. At admission, clinical examination revealed poor general condition, fever (39ºC), noral blood pressure, and the abdominal examination showed no abnormalities. Laboratory results revealed an stable haemoglobin of 13 g/dL, leukocytosis (19850/UI) and neutrophilia (90%), an a C Reactive Protein of 350mg/dl. A Computed Tomography Angiography (CTA) revealed a 3,5 cm saccular juxtarenal AAA, with peri and intra-aortic gas, strongly suggestive of an mycotic AAA (MAA). Hospitalization was indicated and a septic and immunologic screening was perfomed. The patient started a broad-spectrum antibiotic with meropenem and vancomycin and clinical, laboratory and hemodynamic surveillance. Blood and urine cultures revealed a E.Coli infection, and directed antibiotic was started. After 10 days os hospitalization, the patient was haemodinamic stable, presented no fever or abdominal pain, however inflammatory parameters remained elevated, and a new CTA that showed a daunting increase of 4 cm of the AAA (7,5 cm) with signs of contained ruture. An emergency intervention was decided and the patient underwent an thoracophrenolaparotomy and aorto-aortic interposition with bovine pericardium patch. After 24h of surgery the patient died of septic shock. Conclusion: MAA is a rare and threatening disease with rapid progression and high mortality. Even with broad-spectrum antibiotic and rapid surgical response, the tragic outcome is often the unavoidable result
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