Mário Lopes

Experimental shear-dominated response of RC walls: Part I: Objectives, methodology and results

An extensive test programme, aiming at studying the seismic performance of reinforced concrete (RC) walls under extreme conditions leading to shear failure, is described. A new test set-up, designed for this experimental programme with the purpose of imposing beam behaviour and, at the same time, maintaining a low shear ratio, is presented. A description of observed behaviour is offered. Special emphasis is given to the features that are failure mode dependent.

Seismic performance of irregular bridges – comparison of different nonlinear static procedures

The adequate seismic performance of transportation infrastructures is important for the functioning of the economy and society. This paper focuses on the seismic assessment and analysis of one of the most important components of these infrastructures, the bridges. In this field, nonlinear static procedures (NSPs) have gained significant attention, resulting in different proposals to improve the accuracy of the procedures while keeping their simplicity. The main goal of this study is focused on the evaluation of the applicability of NSPs for irregular reinforced concrete viaducts. A comparative approach is pursued by resorting to (1) the analyses of the performance of three well-known NSPs (N2 method, modal pushover analysis and adaptive capacity spectrum method) and (2) the extension of the scope of previous studies in this field to a more recent method, the extended N2. As such, a set of bridges with different levels of irregularity, configurations and lengths is investigated. The accuracy of different NSPs is evaluated by comparing the results of NSPs with the ones obtained by means of nonlinear dynamic analyses. The comparison of results confirms the acceptable performance of the multi-modal NSPs and highlights the effectiveness of extended N2 method with respect to its simplicity.

Experimental shear-dominated response of RC walls. Part II: Discussion of results and design implications

Abstract A detailed discussion of the results of the tests presented in Part I (Engng Struct 2000;23(3)229–49), with special emphasis on two main issues is presented: the effect of the tests new boundary conditions, showing that some conclusions from previous tests can not be extrapolated to walls prone to beam behaviour, as is the case in multi-storey buildings; the shear resistance at the plastic hinges, leading to the identification of the corresponding mechanisms of resistance and the evaluation of the respective capacities at the ultimate limit state.

Pombalino Constructions: Description and Seismic Assessment

This chapter describes the Pombalino building structures built in Lisbon downtown and other parts of Portugal during the reconstruction after the 1755 earthquake, as well as their earthquake resistant features. In particular the importance of the Gaiola Pombalina, a tridimensional wood truss characteristic of those constructions, in the potential seismic resistance of these buildings is discussed. The effects in their seismic resistance of the architectural and structural changes to which these buildings have been submitted since the original construction, usually with negative consequences,, is also discussed. Some strengthening and advanced analytical modelling strategies for these buildings are also mentioned. Finally, the socio-economic feasibility of strengthening this construction is briefly discussed, as well as the importance of their preservation. To be noticed that the reconstruction of Lisbon is the first time in the history of mankind that a large town was built providing widespread seismic resistance to its buildings aiming at avoiding future tragedies of the same type.

Seismic Behavior of Dual Systems with Column Hinging

In order that moment-resisting frames exhibit adequate ductile behavior under seismic actions, it is necessary that inelastic deformations spread throughout the height of the frames. It is widely accepted that this is only possible if vertical members remain essentially elastic, such as enforced in the most advanced codes of practice. The results of nonlinear dynamic analysis shown in this work demonstrate that this is not the case if frames resist earthquake ground motions together with structural walls. This was attributed to the fact that these elements prevent the development of sidesway mechanisms even if plastic hinges form at all column extremities at a given floor. As a consequence, it is proposed to relax the capacity design procedures for design of ductile frames that resist earthquake ground motions together with structural walls.

Development of a Common (European) Tool to Assess Earthquake Risk Communication

This paper reports work on an on-going EC project called KnowRISK aimed at reducing the seismic risk from non-structural elements in buildings. Specifically it reports work on the development of a European tool to assess the effectiveness of risk communication interventions and awareness raising training with middle and high school children in case study areas in Portugal, Italy and Iceland. It describes the difficulties research teams faced in agreeing a theoretical framework and in devising the survey tool. Although they all agreed it was essential to have a common survey if the findings from the research were to be compared across the three countries, one year into the two-year project two of the teams were moving in different directions. This was significant since some of the pre-intervention surveys had already been conducted. Both theoretical frameworks had merit and each of the questionnaires were capable of assessing the efficacy of the training. However, they were in no way comparable. Finally the paper details how these difficulties were resolved and a common questionnaire was devised that embodied virtues from both surveys. This was then applied in all three countries to provide comparable data, the findings from which will be reported elsewhere.

Seismic Risk Communication: How to Assess It? The Case of Lisbon Pilot-Area

This paper aims to present and discuss the theory and research strategy underlying the assessment of the KnowRISK risk communication in one of the KnowRISK pilot-areas, Alvalade parish in Lisbon city. The theory guiding this evaluation research stands on Precaution Adoption Process Model (PAPM), and is complemented by other proposals. Defining the most appropriate research design required answers to two basic questions: ‘what to assess?’ and ‘how to assess?’. The first-mentioned question implied to take into account KnowRISK risk communication main aims, clarifying which cognitive and behavioral changes were realistically expectable in the context of an earthquake dormant society as is the case of Lisbon. Concerning the second-mentioned question, the assessment of risk communication procedure stands in an evaluation research design that comprehends quantitative and qualitative methods.

How to Survive Earthquakes: The Example of Norcia

In this paper lessons are extracted from the comparison between the very different consequences that similar earthquakes had on the neighbouring towns of Norcia and Amatrice during the 2016 seismic crisis of central Italy. It was found that the differences in damage were essentially due to the strengthening of most houses in Norcia done during the previous decades. This is also likely to lead to a much faster recover of the economy and livelihood in Norcia, as Amatrice needs to be entirely rebuilt.

Seismic Performance of Non-structural Elements Assessed Through Shake Table Tests: The KnowRISK Room Set-Up

In the scope of the KnowRISK research project a set of tests were carried out on the LNEC-3D shake table in order to assess the seismic performance of several non-structural elements and building contents. The aim was to create a room that was as realistic as possible, not only in terms of spatial arrangement but also in terms of furniture and decorative objects. This would allow the presence of daily-life objects and furniture that can represent hazard inside regular homes during an earthquake. Damages were observed with increasing intensity seismic motions. In some of the tests different non-structural protective measures were implemented in order to observe how they mitigate the damage. Videos of the entire set-up were recorded during the tests, for the KnowRISK interventions, and accelerations were measured in a wardrobe and a bookcase. This allowed to obtain qualitative as well as quantitative data about the objects’ seismic performance.

KnowRISK Practical Guide for Mitigation of Seismic Risk Due to Non-structural Components

Good performance of non-structural elements can be decisive in saving lives and costs when an earthquake strikes. The European project KnowRISK aims to educate and encourage households to take the necessary precautionary measures to protect people, houses, and contents. Preparedness and prevention act on community resilience. Within the KnowRISK project, the idea of a Practical Guide has been conceived suggesting seismic mitigation solutions for non-structural components to non-experts stakeholders. It is intended to guide people into the first steps of prevention in a straightforward manner, minimizing or avoiding injuries, damage, and long-term financial consequences. The novelty of the Guide belongs to his philosophy: a path through increasing challenges corresponds to a growing level of safety. The idea is that anyone can mitigate seismic risk in its own environment by adopting simple and low cost measures. The Practical Guide may contribute to increase risk awareness. This kind of initiatives if undertaken at larger scales may also enhance social resilience.