Abstract

A few months after the San Francisco earthquake and fire in April 1906, the prosperous and cosmopolitan city of Valparaíso (Chile) suffered a similar catastrophe, sparking the forerunner application of new materials and construction systems. After the earthquake, reports, and articles were produced analysing the characteristics of the earthquake and its effects on the built environment, emulating at a more basic level those emanating from the ad hoc commissions created to analyse the earthquakes in San Francisco and Messina (1908). At the theoretical level, solutions for reconstruction were discussed between reinforced concrete and steel structures, and the applications of these new materials, structural systems, and constructions in the world were closely observed. The solutions used for reconstruction ranged from proven inefficiencies prior to the earthquake to new techniques and materials. In this area, the use of steel with imported pre-manufactured systems as well as local solutions stands out. The need to reconstruct public and private buildings in Valparaiso with a reliable and fast system leaned the choice at the beginning towards the use of pre-manufactured metal structures. The article will expose and analyse the discussions of the time regarding construction systems and materials from a seismic-resistant point of view, complemented with the description of three emblematic cases of metal medium height construction in Valparaiso, after the earthquake: the Hucke Factory, Cardonal Market and the “Jabonería La Estrella” Factory.

Abstract

The saddle-shaped shells, or hyperbolic paraboloids, often joined together to form a pitched roof or an inverted umbrella, were used by many pioneers in structural architecture, such as Félix Candela, which introduced a very innovative use of reinforced concrete in thin layers or together with some reticulated ribs. An innovative semi-prefabricated building system was developed in Italy in the years ’30 of XX cent by a very active brick factory near Piacenza, RDB: the SAP system, that allowed building curved surfaces by prefabricating light elements. After WW2, this technique was applied also for the new structures covering wide spaces for the developing industry or also for public leisure, using prefabricated panels of the desired length. A particularly interesting application was the BISAP (double-SAP) panel that could be adapted for building large shells. In Codogno (LO), Italy, the BISAP panels were employed to cover a large sports hall, spanning about 37 × 26 m, without intermediate supports, resting (mainly) on the four corner pillars. Border pitch beams sustain at the top two crossed beams that separate (and support) the four hypar fields. On the four sides, two rafter beams are connected by horizontal prestressed tie beams, in order to minimize displacements and assure the preservation of the original shape. The first aim of the structural analysis was to assess the static conditions of the roof under the service loads assigned by Italian code for SLS, and then to evaluate seismic vulnerability at ULS of the whole sports hall, being a public space subjected to particular safety provisions. The FE code used (Straus7) allowed a very careful discretization of the orthotropic slab with the correct inclination and twist of the ribs, giving a reliable forecast of the behavior also in seismic conditions: the dynamic analysis of the modal shapes gives a satisfactory response of the shell, which maintains nearly unchanged his shape during free vibration modes. The seismic safety of the structure can be then increased by simply augmenting the stiffness of the four corner supports, where shear action is concentrated, by adding ribs to the L-shaped sections to form cross shaped ones. In this way also the slenderness (and weakness) of additional intermediated pillars could be overcome.

Abstract

The construction industry uses a complex combination of materials associated with a high carbon dioxide footprint. Therefore, several new building systems and solutions have emerged with higher sustainability and improved energy efficiency over their service lives, with the development of customizable lightweight sandwich structures, being one of the most promising strategies. The common processes for manufacturing fibre-reinforced polymer (FRP) composites, with large dimensions, are both hand layup-assisted vacuum bagging and vacuum bagging infusion. Besides, composite sandwich panels are traditionally composed by glass fibres and thermoset resins. However, basalt fibres can be an interesting substitute, since they are more sustainable, and have a higher performance. Despite the large amount of research work carried out on advanced composite sandwich panels, only a few studies were focused on the manufacturing of these structures based on basalt fibres assisted by vacuum infusion. Therefore, this work aims to design, manufacture and compare the mechanical, physical, thermal and environmental performance of these composite sandwich panels, comprising either glass or basalt fibres, which will be further applied in modular construction. The results revealed that it is feasible to produce composite sandwich panels through this method, and the most promising solution attained through this study is based on basalt fibres.