Structural analysis & feasibility study of the nervi system

Abstract

The Nervi System is not just a particular structural solution. On contrary, it is a holistic design process, from inception to design to production and final construction. Throughout his career, the renowned Italian structural engineer, Pier Luigi Nervi, came up with a number of innovative solutions, which challenged the traditional practices of his time. The focus of this research study will be the investigation of one of Nervi's inventions - the isostatic ribbed slab, in the multi-disciplinary context created by the Nervi System. The motivation behind this research is to analyse a prime example of engineering thinking whereby structural theory is used to solve a traditional structural problem in the interest of ease of construction, aesthetic quality and economic cost. The first part of this study involves the identification and location of the patents relevant to the Nervi Systems. Subsequently, their practical application is analysed through a number of case studies of Nervi's work. Five of these case studies are modelled and analysed using Finite Element Analysis (FEA) software. The FEA package used for all the numerical modelling carried out in this dissertation is SCiA Engineer 16.0. The objectives of this research study are the following: - The familiarization with all the aspects relevant to the isostatic ribbed slab, including the construction process, the materials and the underlying structural theory. - An analysis of the extent and role of the structural theory in determining the choice of the ribs and their configuration. In addition, the effect of the stiffening ribs on the behaviour of the slab is also analysed. - Finally, the feasibility of this structural solution is verified in terms of structural material use as opposed to different slab types. This dissertation is divided into six chapters, each outlining a different aspect of the above mentioned objectives. The first chapter gives a brief introduction about the concept of form as a diagram of forces. The second chapter presents the literature related to the Nervi System, including a brief description of the socio-economic context, the materials used and the construction system. It proceeds to describe more recent research studies relating Nervi's work to the new concept of topology optimization. Chapter Three includes an in-depth study of five relevant examples of Nervi's work, the numerical modelling of which is explained in Chapter Four. The results obtained from the analysis of these models are presented in Chapter Five. Finally, Chapter Six integrates all the knowledge gathered through this research study in order to address some lacunae in our understanding of Nervi's thought process in design.