Antonio Ricardo Marí Bernat

Design Proposal to Avoid Peeling Failure in FRP-Strengthened Reinforced Concrete Beams

According to the available experimental work, the most common failure in existing structures strengthened by plate bonding is the laminate peeling off. In the last few years, an important effort in the development of mathematical models to avoid premature peeling failures has been made. However, a suitable and reliable design method to predict debonding due to the shear flow between crack discontinuities or at the laminate end is still not available. This paper describes a new design procedure for structures strengthened by plate bonding to avoid peeling failure at any location. After calculating the laminate area required for flexural strengthening, a two-step procedure to prevent peeling failure is proposed. The first step, to avoid peeling failure along the span, is based on a shear-bending interaction diagram associated with the theoretical maximum transferred force between laminate and support along the crack spacing before laminate debonding. This interaction diagram can be obtained through the appl...

Estudio del ancho eficaz en secciones en t de hormigón armado e identificación de los parámetros significativos en su respuesta estructural

A study of the effective width of different types of reinforced concrete cross sections /s presented. The method of analysis used is the finite elements method, using shell elements and beam elements to represent the flanges and web respectively. One of the objectives of this study is to identify the more significant parameters in the determination of the effective width. For this purpose, a parametric study has been performed and a number of simple analytical expressions for the effective width is proposed. The obtained results have been compared with the ones coming from other analytical methods and with the ones proposed by the Spanish Concrete Code. Finally some conclusions have been derived.

Damage investigation of a tunnel subjected to an unplanned surface load through non-linear analysis

Abstract A description of the deformations and damage that occurred in a segmental tunnel lining as a consequence of an unplanned surface load is presented, as well as the numerical analyses performed for its safety assessment. The tunnel in study is located in soft soil conditions and presents a low overburden. Few months after tunnel drilling, a new bridge was constructed at surface level, placing an access embankment over the tunnel path. Monitoring points were installed along the affected section which recorded the deformation of the tunnel caused by the embankment weight. More worryingly, despite no additional loads were introduced, the deformation of the lining continued increasing significantly along the next months, indicating the existence of soil consolidation phenomena. As a consequence, structural cracks emerged along the affected section. Non-linear finite element models that realistically simulate the behaviour of the non-linear segment joints and the concrete cracking were used to characterize the actual response and strength of the lining. The results showed that most significant damages should occur at the non-visible extrados side, and characterized how they evolve along the soil consolidation process. Finally, the adopted tunnel strengthening procedure is described.

Comparación de resultados obtenidos en el proyecto de estructuras de hormigón aplicando la Instrucción EHE-08 y el Eurocódigo 2

Resumen La Instruccion Espanola de Hormigon Estructural EHE-08 fue el resultado de una profunda revision de la anterior Instruccion EHE-98, sobre la que se realizaron numerosas modificaciones orientadas a adaptar la Instruccion al actual marco normativo europeo y al actual estado del conocimiento, promover la mejora de la calidad de las obras sin sobrecostes injustificados y contribuir al desarrollo sostenible. En dicho contexto, se realizo un trabajo orientado a comparar los resultados de aplicar la Instruccion EHE-08 y el Eurocodigo EC-2 al proyecto de diferentes estructuras. Se estudiaron seis tipos estructurales, que se consideran representativos de las obras de hormigon estructural mas frecuentes en Espana y que ademas cubren un amplio espectro de las tecnicas de construccion estructural (hormigon armado y hormigon pretensado con armaduras pretesas y postesas, construccion prefabricada y construccion in situ, estructuras de edificacion y de obra publica).