Carlos Sousa

Petrobras (Brazil)

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Long-term monitoring and assessment of a precast continuous viaduct

Structure and Infrastructure Engineering (2011)

Hélder Sousa Carlos Sousa Afonso Serra Neves João Bento Joaquim Figueiras

Precast girders have recently been widely employed in the construction of bridges and viaducts. The new bridge over the Tagus River in Portugal, the Lezíria Bridge, comprehends a 9160 m long south approach viaduct, which was built with precast girders made continuous in situ. Given the relevance of this construction, a long-term monitoring system was implemented and measurements were taken since the start of the construction. The observed parameters were concrete strains and temperatures, deck rotations, joint displacements, accelerations and also environment temperature and relative humidity. The work presents the precast structure, the monitoring system and the appraisal of a statistical procedure for the long-term assessment of the structural behaviour. This procedure is based on prediction models, which establish the normal correlation patterns between environmental and material parameters (such as concrete temperature and shrinkage strains), and the observed structural response in terms of strains, rotations and movements of expansion joints. The calculation of the normal correlation pattern comprehends the minimisation of a square error. By applying the prediction model to the structural response measured in the south approach viaduct of the Lezíria Bridge, it was found that this methodology is a feasible tool for real-time damage detection of bridges.

Precast concrete

Structural Health Monitoring

Prestressed concrete

Bridge (graph theory)

10.1080/15732479.2011.614260

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Citations (9)

Measured and calculated influence lines in a concrete frame bridge structure

CRC Press eBooks (2016)

Carlos Sousa Filipe Cavadas Joaquim Figueiras

Structural health monitoring (SHM) of bridges and, in particular, the development of efficient and reliable damage detection methodologies have been given a huge attention over the last three decades, by both the scientific community and bridge owners. Damage detection techniques involve the comparison of the structure's response obtained in the monitoring stage with that of a baseline condition. The damage detection process generally involves five increasing knowledge steps ranging between, in a first stage, signalizing the occurrence of damage and, in a last stage, assessing its effects on the safety and lifecycle of the bridge. Therefore, detailed assessment and characterization of the in-service behaviour of the structure is paramount for successfully completing the damage detection process. With the aim of applying sound damage detection approaches based on the quasi-static component of moving-load responses in concrete bridges, this paper is devoted to the analysis of the in-service behaviour of these structures under moving-loads. A reduced-scale laboratorial model of a reinforced and prestressed concrete frame, subjected to a moving-load, was chosen as the case study. Although the laboratorial structure is not a scaled down model of a bridge, the authors believe that its response is representative of the behaviour of typical full-scale frame concrete bridges. Furthermore, it is noteworthy that smeared cracking might be observed along the frame's beam, which is typical in concrete bridges. The structure under analysis was subjected to an extensive set of experimental tests, which comprised the observation of the structural response during the passage of a moving point-load, both forward and backwards, for different loads and under different prestress force scenarios (Cavadas & Figueiras 2014). That study revealed that, even though the pre-existing cracks remain entirely under compression (thanks to the applied prestressing forces) during the passage of the moving load, the structure exhibits a non-linear behaviour. This behaviour has important implications in the context of the application of damage detection techniques to cracked beam structures. On the one hand, it implies that the experimental influence lines become dependent on the direction of moving loads. This fact was evident in the experimental tests, where different influence lines for displacements, rotations and strains were obtained for forward and backward movement directions. On the other hand, the non-linear behaviour also implies that the beam's deformations due to a constant point load will change if the prestressing force is modified. In this context, the main purpose of the present paper consists in the discussion and justification of the nonlinear behaviour observed in the laboratorial model. For that purpose, detailed finite element analyses were conducted. Nonlinear constitutive models were adopted to simulate the cyclic behaviour of cracked reinforced concrete structures. Special attention was devoted to the bond-slip behaviour at the interface between the reinforcing bars and the surrounding concrete, and also to the cyclic relationship between the local crack width and the concrete stress normal to the crack. The nonlinearity of concrete in compression was not considered because the structure is subjected to reduced concrete compressive stresses. The supports deformability was also considered in the analyses. Finally, it could be demonstrated that the observed nonlinear response is due to two main reasons: (i) the hysteretic behaviour of cracked reinforced concrete elements, which occurs even when pre-existing cracks are entirely under compression; (ii) the supports deformability. Even though the results and discussions presented in this paper were obtained for a reduced scale laboratorial model, the phenomena under analysis can be found in real structures and therefore, this subject is relevant in the context of the application of damage detection techniques to real bridge structures.

Bridge (graph theory)

10.1201/9781315207681-360

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Parametric study of the minimum required reinforcement for cracking control in thick restrained RC members based on thermo-hygro-mechanical FE analyses

Carlos Sousa Miguel Azenha Cláudio Ferreira Rui Faria

This work was financially supported by: Project POCI-01-0145-FEDER-007457 (CONSTRUCT - Institute of R&D in Structures and Construction) and by project POCI-01- 0145-FEDER-007633 (ISISE), funded by FEDER funds through COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao (POCI), and by national funds through FCT - Fundacao para a Ciencia e a Tecnologia. FCT and FEDER (COMPETE2020) are also acknowledged for the funding of the research project IntegraCrete PTDC/ECMEST/1056/2014 (POCI-01-0145-FEDER-016841). The financial support of COST Action TU1404 through its several networking instruments is also gratefully acknowledged.

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Nonlinear modelling of shrinkage-induced deformations on RC retaining walls

Luís Leitão Rui Faria Miguel Azenha Carlos Sousa

Shrinkage

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Citations (2)

Numerical analysis of a RC slab considering the combined effect of self-induced stresses and external loads

Taylor & Francis eBooks (2008)

Miguel Azenha Rui Faria Carlos Sousa

Slab

10.1201/9780203882955.ch72

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Long-term behaviour of a viaduct made with precast beams

Carlos Sousa Hélder S. Sousa Afonso Serra Neves Joaquim Figueiras

Precast concrete

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ESP Testing: A Key Role in Enhancing Reliability

B. P. Foresti A. M. Viana Francisco Raphael Ribeiro Bacellar J. A. G. Silva Manuel S. Neves

Electrical Submersible Pumps (ESPs) have been manufactured since 1928 [1], and since then, much has changed regarding the equipment and its application scenarios. When they were first invented, ESPs were used in onshore fields for short tie-backs. Since then, the application scenario has changed significantly. Conversely, for Petrobras, they are mostly used in deep-water offshore fields with wet Christmas trees and long tie-backs, in most cases, inside subsea equipment (such as MoBo [2] or skid-mounted ESP [3]). For the latter scenario, denominated as critical wells in Petrobras, the resources and costs involved in installing a new ESP and retrieving a faulty one are very different from those in the onshore scenario. Considering the rig costs and deferred production, for a subsea well, one operation might cost more than 30 million dollars. In the case of a premature failure that requires retrieving the faulty equipment and installing a new one, the impact is hence more than 60 million dollars. Once again, this is a very different scenario from the onshore scenario. The world’s first ESP in a subsea well was installed by Petrobras in RJS-221 (Carapeba field) in 1994, in shallow water. Following that, in deep water, Petrobras installed an ESP in RJS-477 (Albacora Leste field) in 1998 [4]. From 1998 to around 2008, Petrobras experienced numerous premature failures with ESPs. The situation was so dire that there was even consideration given to abandoning the use of ESPs in favor of gas lift. This would result in lower production but also reduced deferred production and decreased workover costs.

10.2118/219522-ms

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Fatigue analysis of a railway bridge deck slab considering the influence of simultaneous train crossings

Report (2013)

Carlos Sousa João Francisco Rocha Rui Calçada Afonso Serra Neves

<p>Fatigue analyses play an important role in the context of railway bridge decks assessment. This type of structure is usually subjected to important cyclic loads due to railway traffic, and consequently, the fatigue phenomenon has to be taken into account. In this paper, a recently developed numerical methodology for fatigue analyses is applied to the study of a typical bridge deck configuration, which consists of a double track structure made with precast U-shaped girders connected by a thin cast-in-place slab. The study focuses on the fatigue behaviour of the deck slab and girder webs, considering the influence of crossings of trains travelling in opposite directions. The developed numerical methodology takes into account the statistical properties of the location of the point where the trains cross. The most critical points in terms of fatigue verifications and the practical implications of train crossings are shown by means of a parametric analysis.</p>

Precast concrete

Slab

Bridge (graph theory)

10.2749/222137813806520974

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Long-Term Experimental Campaign on RC Shrinkage Cracking: Conceptualization, Planning and Experimental Procedures

Rilem bookseries (2021)

José Gomes José Granja Carlos Sousa Cláudio Ferreira Dirk Schlicke

Shrinkage

Experimental data

10.1007/978-3-030-72921-9_12

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Experimental validation of the FE model for dynamic analysis of a composite railway viaduct's deck slab

Report (2019)

Joel Malveiro Carlos Sousa Rui Calçada Diogo Ribeiro

<p>The experimental validation of FE numerical models, performed through the comparison between measured and calculated responses, presents an important step in further detailed calculations or simulation of future scenarios. Several parameters to be taken into account in numerical analyses, such as the cut-off frequency, train speed or damping coefficients, might have a preponderant effect in the success of that validation. Therefore, this paper discusses and evaluates the effect of these parameters in the numerical analyses to be carried out on a FE model of the Alcácer do Sal railway viaduct, under the passage of an Alfa Pendular train with a speed equal to 220 km/h. The dynamic behaviour of the deck slab is evaluated, through a methodology that considers train-bridge interaction, taking into account frequency limits equal to 15, 20 and 30 Hz, small variations in the train speed and two different scenarios of damping coefficients.</p>

Slab

Bridge (graph theory)

Bridge deck

10.2749/guimaraes.2019.0697

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