Artigos de Revista

Neste artigo, dedicado à temática da garantia de condições globais de segurança em soluções residenciais especialmente adequadas para idosos e pessoas fragilizadas, mas marcadas por um essencial quadro intergeracional, participativo e bem integrado em termos sociais, urbanos e arquitetónicos, abordam-se, sequencialmente, as seguintes matérias: (1) aspetos globais de segurança numa habitação adequada a idosos, assunto este estruturado, em termos de níveis físicos, nas temáticas da segurança na vizinhança e da segurança na habitação ; (2) questões considerada fundamentais da segurança residencial ligada à crítica ocorrência de acidentes domésticos ; (3) e, finalmente, uma atenção específica ao muito grave problema das quedas na habitação para fragilizados.

This paper is focused on the study of the dynamic behaviour of two large arch dams, and it presents some innovations for the improvement of Seismic and Structural Health Monitoring (SSHM) systems for dams. The work describes a methodology based on the integrated use of software for automatic monitoring data analysis and of computational 3D finite element (3DFE) models for dam dynamic behaviour simulation. The monitoring data analysis software was developed for automatic modal identification, in order to obtain natural frequencies and mode shapes, for automatic detection of vibrations induced by seismic events, to be distinguished from those caused by other operational sources, and for comparison between results retrieved from measured vibrations and numerical results from 3DFE modelling. The numerical simulations are carried out using a 3DFE program developed for dynamic analysis of dam-reservoir-foundation systems, based on a solid–fluid coupled formulation and considering the dam-water dynamic interaction, including calculation modules for complex modal analysis and for linear and non-linear seismic analysis. The case studies are two large arch dams that have been under continuous dynamic monitoring over the last ten years: Cabril dam (132 m high), the highest dam in Portugal, and Cahora Bassa dam (170 m high), in Mozambique, one of the highest dams in Africa. The SSHM systems installed in both dams have similar schemes and were designed to continuously record accelerations in several locations at the upper part of the dam body and near the dam-foundation interface, using uniaxial and triaxial accelerometers. The most significant experimental results from continuous dynamic monitoring are presented and compared with numerical results for both dams, with emphasis on the evolution of natural frequencies over time, including the vibration mode shapes for various water levels, and on the measured accelerations during low-intensity seismic events. Furthermore, the main results of non-linear seismic response simulations are provided, considering the effects due to joint movements and tensile and compressive concrete damage, aiming to assess the seismic performance of both dams based on the Endurance Time Analysis method.

Marine fenders provide the necessary interface between berthing ships and berth structures (PIANC, 2002). Their absence can cause damage to either the quay or the ship or both the quay and the ship, endangering lives, and property. Due to the complex hydrodynamics around berthing ships, the characterization of the maximum force applied to an individual fender and the force distribution among a set of fenders is an essential factor in the design and safety of maritime structures and the fenders themselves, as well as for improving existing ones. This paper aims to describe a combining physical and numerical modelling of a ship impact on fenders, in order to improve the numerical modelling of this problem.Physical modelling represents a good practice in hydraulic studies, where a scale model is used to reproduce complex dynamic phenomena. However, the use of a sophisticated numerical model (or a package of numerical models) can provide a good means to evaluate the samecomplex physical processes and, in addition, to design and test a large number of alternatives in a short time span.Both types of models have their strengths and weaknesses (Gerritsen and Sutherland, 2011). Physical models provide a natural reproduction of complex non-linear physical phenomena, therefore they are well established and considered to be truthful. On the other hand, these models can be expensive and time consuming. In addition, one has to deal with the scale effect and measurement difficulties and errors are frequent. Numerical models in turn are very efficient to simulate rapidly many physical processes and the results can be easily extracted. On the other hand, to improve the reliability of their use in practice, it is necessary to calibrate several parameters through physical model measurements and field experiments. In order to take advantage of the potentiality of the two models emerged the composite modelling which is the integrated and balanced use of physical and numerical models (Gerritsen and Sutherland, 2011). This technique also costs but provides results with a better quality than those model techniques separately and increases the confidence in the use of numerical models.The physical modeling consists of a ship scaled model, whose impact on the fenders was performed in a wave basin. Various impact velocities and angles between the ship axis and the fenders alignment were used to represent possible collision conditions. The same conditions were reproduced by a numerical package. The numerical modeling was performed using MOORNAV (Santos, 1994), which estimates the ship motions and the forces exerted on the elements of the mooring system, namely mooring lines and fenders.

Esta comunica‡Æo diz respeito … fase de testes do sistema SAFEPORT, tendo-se avaliado o seu desempenho numa situa‡Æo de tempestade. Trata-se de um sistema desenvolvido para a seguran‡a da navega‡Æo do porto de Sines, e, mais concretamente, nos seus terminais de Gran‚is L¡quidos, Multiusos e Contentores. Para estes terminais, simulou-se o impacto da tempestade C‚lia nos esfor‡os nos cabos de amarra‡Æo de um navio petroleiro, de um navio de carga geral e de um navio porta contentores, respetivamente. O sistema SAFEPORT demonstrou ser capaz de antecipar os efeitos nos navios amarrados dos estados de agita‡Æo associados … tempestade C‚lia.

This paper addresses the topic of site characterization for the design of Shallow Geothermal Energy (SGE) systems, namely of thermoactive geostructures, which are geotechnical structures, such as piles, retaining walls and tunnel linings, also used as heat exchangers as part of closed-loop SGE systems. Such solutions, being increasingly adopted for buildings’ and infrastructures’ heating and/or cooling, are considered sustainable and cost effective. For the design of the primary circuit of the SGE system, which is embedded within the superficial soil layers, a comprehensive knowledge of the ground condition at the site is mandatory. This includes the evaluation of the energy features and whether the system can provide the required energy needs during the operational period, as well as the verification of the structural and geotechnical safety and functionality requirements. The site characterization for SGE systems involves different stages, from desk studies to detailed characterization, including in-situ trials, laboratory testing of undisturbed soil samples and the study of possible interferences. The specific aspects that will be addressed are: (i) the assessment of the site undisturbed ground temperature and its hydrogeological features; (ii) the thermal and thermomechanical characterization of the different soil layers; (iii) the investigation of the ground-heat exchanger thermal resistance; (iv) the collection of information related to the environmental constraints and to potential interferences among multiple users, which are related to the service life of the structure. The overall aim is to ensure a proper design of the SGE system for guaranteeing its sustainability in the long term.

Evaluation of the sliding stability of concrete dams requires the use of numerical tools not only able to simulate the coupled hydromechanical behavior but also able to adequately represent the foundation discontinuities and the specific features of dam foundations. The formulation of a threedimensional (3D) small displacement finite element model based on interface elements to simulate the discontinuities is presented. In this model, the hydraulic behavior is simulated assuming that the water flow occurs only along channels located at the edges of the triangular interface elements that simulate the discontinuities. The model is used to perform coupled hydromechanical analysis of a large arch-gravity dam and to assess safety against dam base sliding, assuming different constitutive models at the dam/foundation interface and two different approaches: (i) strength reduction method and (ii) amplification of the hydrostatic pressure, assuming an increase in the reservoir level. The present study shows that consistent results are obtained with the proposed numerical model and that stability analysis should preferably be carried out using the method of increasing the hydrostatic pressure and the corresponding uplift pressures, as this methodology leads to significantly lower safety factors.

No presente texto desenvolve-se, em primeiro lugar, uma reflexão genérica sobre as necessidades habitacionais mais específicas dos idosos, passando-se, depois, para uma reflexão sobre a importância de uma informada e ativa capacidade de escolha e de participação no apuramento de uma habitação adequada aos idosos; afinal há, já qui, uma perspetiva que avança numa importância tendencialmente

The purpose of this Special Issue was to collect and publish technical and research papers, including review papers, focusing on the recycling of road pavement materials to promote pavement sustainability performance. Ten papers were published in total covering the use of construction and demolition waste (reclaimed asphalt pavement, recycled concrete aggregate and glass) and industrial waste (plastic and slag). The application of recycled materials concerns bituminous mixtures, concrete mixtures, and non-traditional interlocking blocks or cobbles. The most relevant contributions of each paper are briefly described in the following sections. The papers involved thirty-four authors from eleven countries of Europe (Belgium, Finland, Italy, the Netherlands, and Portugal), Africa (Nigeria), Asia (Malaysia and Saudi Arabia), Australia, and South America (Brazil and Colombia).

Performance assessment is recognized as an important management tool for urban water systems. This article describes the application of a performance assessment framework for storm water systems, in collaboration with two Portuguese urban water utilities. A performance assessment system was built for each water utility, including objectives, assessment criteria and performance metrics. The results showed the existence of areas vulnerable to flooding occurrences and the need for investment in rehabilitation. The application of the performance assessment framework supports the identification of systems’ vulnerabilities and priorities for intervention. Opportunities and suggestions for improving data collection procedures are identified.

The present project addresses a problem related to the erosion effects on a breakwater barrier due to waves which leads to its degradation and that may eventually lead to lack of functionality of the structure. In the present case, the breakwater acts as a physical barrier between the Atlantic Ocean and the cargo Harbour of Leixäes, in Matosinhos, Portugal, justifying the needs of health monitoring of the barrier.To monitor this structure, with a length of roughly 700 m, the need of a fast data acquisition system led to the choice of imaging techniques which allow for a fast acquisition of a diversified data set. The images were acquired using a high-resolution camera attached to an unmanned aerial vehicle (UAV), enabling a faster and more automated procedure that leads to the systematization of the process, while being compatible with the difficult accessibility of the structure, which is surrounded by sea waves. Point clouds corresponding to the breakwater