Search

La tesi propone una metodologia di valutazione quantitativa dell’impatto ambientale dei trattamenti dei terreni organizzata su 3 fasi e basata su un protocollo (Envision) di valutazione della sostenibilità delle infrastrutture, ambito prevalente di esecuzione dei trattamenti in esame, abbinato ai criteri DNSH forniti dall’UE nell’ambito del programma Green Deal. Le 3 fasi consistono in una prima valutazione Envision/DNSH, scegliendo i parametri di valutazione adeguati al caso dei trattamenti dei suoli, una fase di approfondimento tramite analisi LCA (Life Cycle Assessment), i cui risultati in termini di impatto ambientale del trattamento servono per un affinamento, durante la terza fase, della valutazione Envision/DNSH. Il metodo è stato sperimentato su un caso pilota, uno scavo sottofalda in sabbia in un’area in prossimità di Milano, in cui la stabilità delle pareti e la loro impermeabilità è stata garantita dal trattamento. Sono stati studiati i casi di 5 tecnologie diverse (iniezioni per permeazione, jet groutng mono- e bi-fluido, congelamento con salamoia e con azoto liquido). I risultati hanno permesso sia di analizzare le singole tecnologie di trattamento sotto l’aspetto della sostenibilità, sia di porle a confronto. La tecnologia del congelamento è risultata in generale la meno impattante, mentre i trattamenti di jet grouting hanno risentito decisamente dell’utilizzo, nell’ambito del processo esecutivo, del cemento, la cui produzione, come evidenziato tramite l’analisi LCA, risulta a sua volta molto impattante. La metodologia sperimentata, con la sua valutazione quantitativa circa i trattamenti dei terreni, permette ai gestori di infrastrutture di scegliere in modo informato quali siano le strategie più adeguate da applicare nell’ambito della progettazione o gestione dell’opera in esame, ai progettisti di valutare, proporre e dimensionare interventi valutati nell’ottica di una sostenibilità economico-ambientale, agli esecutori dei trattamenti per ot, The thesis proposes a methodology of quantitative assessment of the environmental impact of ground treatments organized in 3 phases and based on a protocol (Envision) of sustainability assessment of infrastructure, for which construction the considered treatments are widely use, combined with DNSH criteria provided by the EU under the Green Deal program. The 3 phased method consists of: an initial Envision/DNSH assessment, choosing the evaluation parameters appropriate to the case of soil treatment; a deepening phase through LCA (Life Cycle Assessment) analysis, the results of which in terms of the environmental impact of the treatment serve to refine the Envision/DNSH assessment during the third phase. The method was tested on a pilot case, an underground excavation in sand in an area near Milan, where the stability of the walls and their impermeability was guaranteed by the treatment. Five different technologies were studied (permeation grouting, mono- and bi-fluid jet grouting, brine and liquid nitrogen artificial ground freezing). The results made it possible both to analyse the individual treatment technologies from the point of view of sustainability and to compare the technologies to each other. The freezing technology was generally the least impacting, while jet grouting treatments were strongly affected by the use of cement in the executive process, the production of which, as evidenced by LCA analysis, is also very impactful. The tested methodology, with its quantitative assessment of soil treatments, allows: infrastructure managers to make an informed choice of the most appropriate strategies to be applied in the context of the design or management of the project under consideration; designers to evaluate, propose and dimensioning interventions evaluated with a view to both economic and environmental sustainability; the performers of treatments to optimize their resources towards the sustainability, documenting the value "green" materials, machinery and p

Permeation grouting treatments can be considered a well-established ground improvement strategy in urban built environments, where an accurate fine-tuning of its components can lead to tailored and efficient interventions. However, how to improve its overall environmental impact remains an open question. Using the Life Cycle Assessment (LCA) approach emphasizing the construction phase, this research highlights the leverages that can improve the environmental performance of this geotechnical construction process. The alternative approaches in terms of materials and processes are identified, quantified, and compared using the standard output of the LCA analysis and represent the ideal input for the three-phased sustainability assessment method for geotechnical infrastructure developed by the authors.