Structural optimization as a sustainable design strategy: the case study of Capo d'Orso military complex in Sardinia

The aim of the proposal is to explore techniques and methods permitting take into account different requirements in the design process. An integrated approach to design is employed, which considers various questions, strategies, and actions applied to a case study in Sardinia, the abandoned military battery of Capo d'Orso. The refurbishment project highlighted key issues, such as seamless integration of new and existing structures, economic feasibility, and efficient use of resources, minimizing the environmental impact of buildings throughout their entire lifecycle, with the goal of repurposing historical buildings. This paper specifically describes the process of integrating and optimizing the structure of the addition required for the re-functionalization of the area. The volume is located above the underlying pre-existing historic vaults, which are intended to be preserved and protected, given their great testimonial value. The work describes a multi-objective optimization approach that evaluated different design alternatives according to the constraints given by the context and the objectives, in order to optimize the structural members to the greatest extent possible while meeting all requirements: structural efficiency, visual permeability, lightweight, low environmental impact, and the feasibility of assembly in a specific location with challenging accessibility. The study shows methods to compare different technologies, configurations, and materials, starting from three structural schemes enabling significant spans and developing a finite element model for each configuration to assess their structural performance. The study ultimately advocates for the arch system obtained as the most viable design option that can meet environmental, architectural, and structural requirements, analyzing its structural performances, the modular optimization for the site, and the assessment of materials’ sustainability. The research delves into the topological analysis that led to the definition of the optimal geometry and cross-section of the arch, derived from specific boundary conditions