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Construction has always been a fascinating and challenging aspect of timber gridshells. So far, only three techniques have successfully been used for the erection of such structures: the so-called ‘lift-up’, ‘push-up’ and ‘ease-down’ (Quinn et al. 2015). Inflatable Membrane Technology is here proposed as a new solution and is tested by means of numerical simulations on a simple case study. As a matter of fact, IMT reduces the timber lath’s stress during erection and guarantees an optimal shape control. It also seems suitable to post-form more challenging gridshell geometries, but this aspect still deserves further investigations and experiments.

In book: La bellezza per il rospo (Beauty according to the toad) (pp.221-222), Publisher: CLEAN Edizioni, Editors: Roberta Amirante, Carmine Piscopo, Paola Scala.

Born in the world of mathematics to define all those “equations that express a set of quantities as explicit functions of a number of independent variables, known as ‘parameters’." Its architectural transposition, which was introduced by Luigi Moretti during the Forties, indicates a consistent system of elements and relationships among them, that is founded on the construction of topological rather than metrical spaces. In other words, it identifies the only invariant of each and every design process with the potential of standardization in digital design and allows software developers to release specific programs which are able to support conceptual design in architecture.

This paper describes a new erection technique for post-formed timber gridshells which takes advantage of inflatable membrane technology. Consolidated construction techniques for timber gridshells are based either on “pull-up” / “push-up” (i.e. Mannheim Multihalle) or “ease-down” behavior (i.e. Downland Open Air Museum). However, these techniques show shortcomings already at small scale. When applied to large scale, a lack of a standardised, cost-effective erection method implies that techniques have to be reinvented every time. When construction becomes expensive and laborious, gridshells become affordable only for exceptional projects, such as the Downland Museum or the Mannheim Multihalle. These are among the reasons why gridshells are not widely applied, even if they enable covering large spans with a minimum amount of material; they are built from basic technologies though self-construction; they are fast to construct; they are entirely recyclable. In this work, an inflatable membrane is designed and used to erect a gridshell prototype with a footprint of 55m2. Inspiration comes from the work by architect Dante Bini, who realised thousands of inflatable concrete domes worldwide.

The Italian architect Dante Bini began his studies on shell structures during the 1960s. He developed and refined a form-finding and construction technique to erect a finished large-span reinforced concrete (RC) shell structure through the use of an inflatable membrane. This system was patented in 1964 under the name ‘Binishell’ and, over the following decades, it has been applied to construct hundreds of domes throughout the world. Bini’s invention fitted perfectly into the Italian post-war tradition, as he was, at the same time, the architect and builder of his structures. A few experimental tests were initially performed in Italy, and the first binishells that he lifted after the patent was filed were also constructed there. Since 1966, as a result of Mario Salvadori’s interest, Bini has been recognised internationally. In 1974 he moved to Australia after the NSW Department of Public Works asked him to realise a set of school facilities using the binishell technology. The construction of concrete shells has always been a difficult and expensive process – the preparation of formworks, as well as the installation of curved reinforcing rods before the concrete is poured, require experience and increase the construction costs. Such problems are particularly relevant in the Australian context, where the use of simple and rapid construction technologies has always been a priority. Dante Bini’s life and the binishell technology have been well documented from the historical point of view. However, a detailed report and contextualisation of Dante Bini’s Australian experience is still missing. A first attempt to survey the Australian binishells has already been published by the authors.2 The focus was on placing Bini’s early work within the previous research on pneumatic structures which began in the 1920s. The narrative of this paper instead starts in the 1960s, a period of great media success for RC shells. First, the origin of binishells is described as a natural consequence of three preceding inventions/patents. A timeline of the events that defined Bini’s emigration to Australia is then provided. A full list of the Australian binishells is also included, with detailed information on the archival sources, major alterations and current conditions.

Timber gridshell structures, such as the Multihalle for the federal garden festival in Mannheim or the Downland Museum, have been the result of a creative–generative process that indissolubly ‘welded’ the structural contribution to that of form exploration. The challenging design and construction issues have been typically addressed and resolved in several inventive ways. However, still now, form-finding and erection of timber gridshells present many difficulties. In this regard, this paper aims to provide a series of novel steps to address some of the main design and construction issues that are associated with ‘actively-bent’ timber gridshell structures. First, the main characteristics of the construction process of timber gridshells are described and the basic theoretical concepts for its numerical simulation, through Dynamic Relaxation method, are introduced. Second, a practical method for sizing the laths' cross-section is presented. Third, a new erection technique for timber gridshells is proposed and applied to the construction of a full scale (prototype) structure, the Toledo gridshell 2.0. Fourth, a new bracing system for the same structure, which was built at the Faculty of Architecture, University of Naples Federico II in June–July 2014, is explained and discussed. The paper also highlights the need for further application to validate the techniques explained here, with particular attention being paid for the construction of large scale free-form structures.

Before the introduction of NURBS-based CAD software and optimisation, the design of form-resistant structures was based on the use of either experimental tools (physical form-finding) or analytical surfaces, and architects were challenged in the articulation of spaces from the intrinsic characteristics/rules of structural forms. An outstanding example of this kind is provided by the Church of Longuelo, which was built by architect Pino Pizzigoni in Italy, between 1961-1966. It was conceived as composed by two major elements – an irregular frame and a set of shells suspended to it. The entire design process was based on the calculation of the frame on which the shells have been just added as a dead load. This paper presents one possible way to redesign the church parametrically. Comparison with the original design is not performed at the final formal level, which can logically differ, but around the concepts behind the project. The aim is to show how current digital design and optimisation tools are affecting the way architects design. But, at a higher level, the purpose is also to highlight where conceptual design is now taking place in the process.

In book: "AAD Algorithms-Aided Design. Parametric strategies using grasshopper", (pp.352-359). Publisher: Le Penseur. Editor: Arturo Tedeschi.

In architecture and structural engineering, ‘form-finding’ identifies the process of designing optimal structural shapes by using experimental tools and strategies, i.e. physical models, to simulate a specific mechanical behaviour.

The reverse hanging method is the oldest and probably most diffused form-finding technique for arches, vaults and shells – a physical model, made with elastic cables or membranes with no rotational stiffness, is first subject to gravitational forces to obtain a structural state of pure tension; such a form, which is called “funicular”, is then inverted to identify the mechanical compression-only situation.

This principle was first mentioned in a publication by Robert Hooke in 1675 . With a Latin anagram, only solved in 1701, he proposed to reverse the curve which was generated by a hanging chain, under self-weight and supported only at its ends, in order to define the optimal structural form of an arch. Such a curve is called “catenary” when the chain presents a constant distribution of weight . Initially confused with a parabola by Galileo Galilei, the catenary was then mathematically described by David Gregory in 1697.

Reciprocal systems based on superimposition joints, i.e. where un-notched bars sits on the top or in the bottom of each other, could be regarded as being intrinsically three-dimensional because of their natural out-of plane development. This paper presents seven of these three-dimensional configurations, conceived and built by the students of the Master of Science in ‘‘Architectural Design’’ at Aalborg University. They have been developed as an integral part of a 2-week workshop, organized and run by the authors during the fall semester 2011. Since physical models are instruments that trigger the exploration of new typologies because of the direct interaction they provide with the designer the students were called to deal with the issue of three-dimensionality in reciprocal systems through scale models and actual scale prototypes.