1,721,059 research outputs found
Effect of creep on the stability of leaning towers
No full textSafety assessment of historical towers is an important challenge in the preservation of the national and worldwide artistic herit-age. This paper illustrates a novel unified methodology developed to evaluate the key phenomena governing the geotechnically related collapse of towers: bearing capacity failure, due to lack of strength of the supporting soil, instability of equilibrium, due to lack of foundation stiffness and a rotational creep process. The analysis, introduced in the framework of a strain-hardening plasticity model for shallow footings, shows that rotational creep is the main cause of the progressive deterioration of stability for real towers. The proposed analytical process is applied to the history of the Santo Stefano bell tower in Venice. This example demonstrates not only the potential of the proposed methodology but also the importance of past rotational records for the pre-diction of the eventual response of such a tower
Geotechnical Investigations and Monitoring of the Archaeological Site of Santa Croce in Ravenna (Italy)
Get PDFThe city of Ravenna, in northern Italy, is worldwide famous for the well-preserved late Roman and Byzantine architectures characterized by fabulous mosaics that have earned the UNESCO World Heritage status. The constantly growing attention towards their conservation has promoted research activities that focus on the effect of the considerable cumulated land subsidence on their current conditions. Today, the sum of long-lasting natural and more recent anthropogenic subsidence has brought the level of such ancient archaeological sites and monuments well below the current position of the phreatic water table, still close to the current ground surface of the city centre, as it is the case of the Santa Croce church and its archeologic area. The Church, dating back to the 5 th Century AD, is surrounded by ancient Roman floor mosaics, located ~3.2 m from the main street level. In this site, a pumping system must permanently operate to lift to the external sewage network the water collected from the local subsoil by means of a rather old and no longer efficient drainage system. A geotechnical investigation campaign was carried out in 2022, together with the installation of a new piezometric monitoring system, with the aim of investigating the shallow aquifers underneath the monuments. Relevant data interpretation will enable to better understand the current situation and, above all, to devise a proper solution which can combine the long-term conservation of the area with its usability
Biological invasions and their threat to ecosystems: two ways to thermodynamic euthanasia
No full textThe compressibility of natural and reconstituted marine clays
Get PDFThere is mounting evidence in favour of replacing the e against log10(s0v) diagram, conventionally used to represent
soil compressibility in an oedometer, with a log(v) against log(s0v) diagram, which significantly improves the linearity
of virgin loading and unloading paths. This paper presents a simple, new formulation of the ‘intrinsic’ compression
and ‘sedimentation’ compression lines for a range of insensitive, sedimentary marine clays presented in Burland’s
1990 Rankine Lecture by using a log(v) against log(s0v) interpretation of the data
Applicazione dei domini di interazione 3d per fondazioni superficiali alla progettazione definitiva di un asse autostradale
No full textIl tradizionale tema della verifica di una fondazione superficiale può essere affrontato mediante i poco diffusi, ma ormai ben noti, domini di interazione 3D. L’impiego di quest’approccio ha consentito, nell’ambito della progettazione definitiva di un asse autostradale, una verifica più rigorosa rispetto al metodo della “pressione limite” tradizionalmente utilizzato. L’obiettivo di ridurre al minimo le iterazioni tra progettista strutturale e geotecnico è stato il fattore discriminante nella scelta di questo metodo di verifica, all’interno di un progetto che prevedeva l’esecuzione di un gran numero di verifiche su diverse tipologie di opere.
Al fine di rendere possibile l’impiego professionale di tali teorie è stato inoltre necessario fornire un’interpretazione articolata delle prescrizioni delle “Nuove Norme Tecniche per le Costruzioni” 14/01/2008, specialmente per quanto concerne i coefficienti parziali γR sulle resistenze
Greenhouse gas emissions from the integrated waste management system and the relevance at territorial scale: The case of the province of grosseto
No full textIn this study, we investigated the main emission sources of greenhouse gases from the waste management system in the Province of Grosseto (southern Tuscany - Italy). The estimation has been included in the general greenhouse gas (GHG) balance of the entire provincial territory for the year 2015. We analyzed the areal waste management system, from waste collection to specific treatment in landfill and five waste recycling plants available within the provincial boundaries. An incinerator is not installed in the area; however, we estimated the Refuse Derived Fuel (RDF) combustion in a hypothetical incinerator. Using the "2006 IPCC Guidelines for National Greenhouse Gas Inventories", we calculated carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) emissions from waste decomposition/incineration and from consumption of electricity and fossil fuels used in all waste management plants, contextualizing the results within the provincial GHG balance that includes energy, industrial and agriculture, land use & forest sectors. The study showed that the Province of Grosseto is not far from a "carbon neutral" status in 2015 and the waste sector covers a relevant part of gross emissions (15.4% of the total). Overall, this waste management system is rather fragmented and improvements in organization and plant selection and connection may help achieve 100% compensation of GHG emission for the Province. We also found that the plant with the greatest impact is the landfill (55.78% of the waste plant emissions). A bottom-up data collection approach has been adopted, generating an overall uncertainty of 14.9% for the GHG inventory. In conclusion, the GHG inventory is a tool able to suggest and validate environmental strategies to reduce the climate impact from waste management, resulting in positive feedbacks on the overall GHG balance of the territory, and influencing the environmental quality and the socio-economic infrastructure of the Province
CO2 recovery from wine production: Possible implications on the carbon balance at territorial level
No full textThe Province of Siena (Tuscany, Italy) is characterized by two features: 1) the carbon neutrality of its territory and 2) the great production of quality wine. The GHG balance of the Province of Siena, realized in time series according to the IPCC guidelines and validated ISO 14064-1 under the REGES Project, testifies the carbon neutrality of the territory (the percentage abatement of gross emissions passed from 72% in 2006 to 106% in 2015). This ambitious goal was achieved in 2011 after the activation of specific environmental policies (concerning energy and waste sectors, forests, transport and education) with local benefits in the short run. This paper presents a systemic investigation of the effects of the application of technologies for carbon dioxide (CO2) capture/storage on the GHG balance of the provincial area; in particular, recovery of biogenic CO2 from alcoholic fermentation of grapes could be seen as a new strategy to consolidate the status of carbon neutrality. The hypothetical installation of recovery plants in Siena wine farms could approximately capture more than 6000 t CO2, corresponding to an improvement of the GHG balance of the territory (i.e. increase of net absorption of almost 8%). CO2 can be captured and stocked in high-pressure containers and reused in production activities, both within and outside the area, avoiding the use of gas obtained in chemical industries by fossil fuel-driven production processes. The economic evaluation confirms good performances obtained by the environmental assessment. These results can inspire policies at the farm level for reducing impacts on GHG emissions from a life cycle thinking viewpoint and at the territorial (or producer consortia) level, in order to decrease impacts by means of dedicated projects, generating positive effects on the local carbon balance and relevant consequences at global scale
Monitoring-driven design of a multiphase intervention for the preservation of the Frari bell tower in Venice
No full textSince the time of its construction in the 14th century, the Frari bell tower has been affected by a slow but constant differential settlement with respect to the adjacent masonry structures of the Basilica. About 15 years ago, the clearly evident signs of structure instabilities provided the impetus for the implementation of modern remedial measures, first in foundation and then on the elevation structure. A ground improvement intervention using soil fracturing (also known as fracture grouting) was carried out in order to improve the mechanical characteristics of the clayey layer underlying the tower. Once the aim of improving the stability of the soil-foundation system had been achieved, a new solution was required to reduce the damaging inter-action between the masonry structures, activated by the foundation settlements. A structural joint between the bell tower and the basilica was finally executed in order to accommodate the system deformability.
The paper presents a well-documented case study, since the preliminary crucial and accurate site investiga-tion, highlighting both the approach aimed at improving the overall safety - without altering the original structure and substantially modifying the current stress distribution - and the innovative methodology, adopted throughout, of a gradual and modular design, constantly driven by the outcome of an extensive real-time monitoring system of the soil-structure interaction
Nitrogen Footprint accounting and food sustainability: Insights from the Italian wine industry
Get PDFAnthropogenic perturbation of the nitrogen cycle poses significant environmental and social challenges, highlighting the need for effective nitrogen management in sustainable food systems. The Nitrogen Footprint (N-Footprint) offers an innovative metric to quantify reactive nitrogen (Nr) emissions and trace their environmental pathways. This study refines a previous N-Footprint accounting framework to include both direct and indirect Nr emissions throughout the life cycle, providing a comprehensive perspective on Nr dynamics. The methodology is applied to a case study of Italian wine production, covering vineyard cultivation, winemaking, and bottling processes. Results indicate total emissions of 7.67 g Nr per 0.75 L wine bottle, with the vineyard phase accounting for 64.4 % of the overall impact, largely due to intensive fertilizer use. Water is identified as the most affected environmental compartment (55.7 % of emissions), primarily as a result of nitrate leaching. Additionally, the study quantifies the Virtual Nitrogen Factor (VNF) to evaluate nitrogen use efficiency. Italian wine production demonstrates relatively high efficiency (2.28 g Nr per gram of nitrogen intake) compared to other fruit-based products. However, the lack of a standardized N-Footprint methodology hinders cross-sectoral comparability. This research calls for the development of nitrogen-specific Life Cycle Assessment (LCA) standards to promote sustainable agricultural practices
MODELING THE EFFECT OF EXCESS PORE-WATER PRESSURE ON THE BEARING CAPACITY OF FULL DISPLACEMENT PILES IN GROUP: A CASE-STUDY IN PARMA (ITALY)
No full textExcess pore-water pressure development during installation of piles into saturated clays is of primary importance and strongly affects pile bearing capacity and settlements. Such a problem is well known in literature, but excess pore-water pressure magnitude prediction, and then that of the bearing capacity, is an open research topic. In addition, excess pore-water pressure may increase greatly when numerous piles are installed in a relatively small area - as in the case of a pile group foundation - thus leading to a non-negligible modification of stress conditions at the soil-pile interface and, as a consequence, to a temporary reduction of ultimate load-bearing capacity. The paper focuses on the interpretation of load-test data performed on several auger-screw piles (full displacement), part of an important soil improvement intervention in Parma (Italy). The analysis of load test showed low values of ultimate load bearing capacity of the tested piles. Hence, the need to investigate the evolution of excess pore-water pressure with time and its relationship with the ultimate pile bearing capacity.
In addition, special attention is dedicated to the study of possible mechanisms standing beneath the superposition of excess pore-water pressure effects among adjacent piles. Eventually, in order to give a consistent theoretical explanation of the recorded data, a simplified model is introduced. Such a model could be applied to similar case studies
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