Modelli empirico - meccanicistici e sistemi inferenziali adattivi neuro - fuzzy per la valutazione del decadimento dell’aderenza delle piste di volo aeroportuali

La ricerca è inquadrata nel settore scientifico disciplinare ICAR/04 “Strade, Ferrovie ed Aeroporti”, settore ERC principale PE - Physical Sciences and Engineering, sottosettori ERC 1. PE8_3 Civil engineering, architecture, maritime/hydraulic engineering, geotechnics, waste treatment; 3. PE8_8 Materials engineering (metals, ceramics, polymers, composites, etc.). Uno dei temi più rilevanti della sicurezza in campo aeroportuale, è la pericolosità associata alle manovre "a terra" dei velivoli (decollo e atterraggio). In tale ambito, il rilievo dell’aderenza assume particolare importanza per il controllo ed il monitoraggio delle caratteristiche superficiali delle piste in uso per gli aeromobili. In particolare, l'azione frenante dei velivoli, in atterraggio o in decollo, è strettamente legata all’aderenza. Dall’analisi delle serie storiche degli incidenti si evince che a fronte di tempi per le operazioni di decollo e atterraggio pari al 2% della durata dell’intera fase di volo si riscontra un tasso di incidenti mortali pari al 37%; di contro, alla fase di crociera che, temporalmente, rappresenta il 57% delle operazioni di volo, è associata una percentuale di incidenti mortali pari solo all’8%. Le manovre “a terra” presentano tre criticità: 1) decelerazione dei velivoli in atterraggio o in decollo fallito; 2) controllo dell'assetto direzionale durante la corsa di decollo o di atterraggio; 3) innesco dello spin-up (rotazione) dei carrelli al touch down. In queste situazioni determinanti per il controllo dell'assetto direzionale, le forze aerodinamiche, innescandosi, possono ridurre l'azione frenante o generare momenti imbardanti. Le condizioni dello strato superficiale della pista influenzano l’entità delle sollecitazioni sugli aeromobili. Le azioni di frenatura in atterraggio o nella manovra di rinuncia al decollo possono essere compromesse da valori insufficienti del coefficiente di aderenza μ. L'innesco della rotazione dei carrelli (spin-up) dopo la toccata (touch down) è fondamentale per il funzionamento corretto del sistema anti-skid. Ad esempio il controllo della traiettoria può essere invalidato se un carrello non raggiunge l'idoneo spin-up inibendo l'anti-skid. Anche l'azione sterzante del carrello anteriore (steering) può essere inficiata da scarsa aderenza della pista. Il Dipartimento di Ingegneria Civile, Edile e Ambientale dell’Università degli Studi di Napoli Federico II conduce da anni, nell’ottica dello studio di base dei fenomeni nonché di un perfezionamento delle Normative di settore italiane, campagne di sperimentazione su aeroporti tra cui l’Aeroporto Internazionale Civile di Lamezia Terme. Le campagne sono rivolte al rilievo e monitoraggio del traffico aereo, delle caratteristiche geometriche infrastrutturali, delle caratteristiche tipologiche e fisico/meccaniche degli strati delle sovrastrutture, delle caratteristiche superficiali delle pavimentazioni, ed alla programmazione della manutenzione in particolare delle piste di volo. L’analisi della bibliografia internazionale rivela l’interesse diffuso dei ricercatori nei confronti dei temi inerenti la gestione delle condizioni delle superfici delle piste. Numerosi sono in tal senso i temi da approfondire, e tra questi di particolare interesse è la perdita di aderenza della pista per gommatura da pneumatici. Le raccomandazioni operative della Normativa di settore, quali ad esempio quelle contenute nella Circolare ENAC APT-10A del 30/10/2014, forniscono eccessiva discrezionalità al Gestore aeroportuale sulle procedure di rilievo ed elaborazione dati. L’obiettivo principale della tesi di dottorato è l’analisi teorico-sperimentale del decadimento dell’aderenza di pavimentazioni per piste di volo, con particolare riferimento alla calibrazione di modelli rappresentativi del comportamento evolutivo dell’ aderenza in funzione dei carichi di traffico (fenomeno cumulativo). La validazione delle variabili predittive dei modelli, la significatività dei dati di traffico, l’affidabilità e la sensitività delle misure di aderenza al variare delle caratteristiche prestazionali e di configurazione geometrica degli aeromobili, sono criteri indicatori utilizzati per la verifica dei risultati conseguiti. Ulteriore misura della attendibilità dei risultati consisterà nell’implementazione dei modelli nei sistemi di gestione delle pavimentazioni delle piste aeroportuali. I modelli elaborati infatti possono essere direttamente impiegati dagli operatori aeroportuali nella pratica tecnica per: predire il degrado dell’aderenza delle piste, con riferimento ai carichi effettivi degli aeromobili nel corso della vita utile degli strati superficiali della pavimentazione; e di conseguenza programmare le attività di manutenzione necessarie per garantire la sicurezza delle manovre a terra degli aeromobili

LINEAR SCHEDULING ANALYSIS TOOLKIT FOR ROAD AND AIRPORTS CONSTRUCTION PROJECTS

The Linear Scheduling Method (LSM) is the most effective scheduling tool to use in linear projects. Computer programs have been developed for various scheduling techniques such as Bar Chart, PERT and CPM. There are not many commercially available toolkit for LSM and this lack of toolkit is one of the reasons for its limited usage. The product of this research is a toolkit comprised of models, procedures and tools that allow for implementation of the linear scheduling method. This toolkit is able to calculate the controlling activity path of such schedules, to level the resources of a project scheduled and to print reports of the status of the schedule. The paper describes the toolkit that was developed by the research, its documentation and example for an Italian case study that was scheduled using this prototype

CRASHES COMPARISON BEFORE AND AFTER SPEED CONTROL CAMERAS INSTALLATION: CASE STUDIES ON RURAL ROADS IN LITHUANIA AND ITALY

The study focused on the appraisal of the effectiveness of fixed speed control cameras regarding the reduction in crashes on the main study road in Lithuania. The task is to install the same technical reliable and validated solutions on homogeneous road sections in Italy that reflect the same geometric, traffic features as well as driver speed behaviour than those observed in Lithuania. The case studies were Via Baltica in Lithuania and S.P.430 in the Southern Italy. Three main roads belong to Via Baltica (A5, A8, A10) where a total of 191 crashes occurred during five years (2009−2013) of study with 276 injuries and 69 deaths. A total of five fixed speed cameras were placed on A5 road, two on A8 road and four on A10 road. After the installation of the speed control cameras, it was observed in two years a reduction in the number of crashes with deaths (51%) and injuries (27%) as well as a decrease in the crash rate values (19%). The case study in Italy was S.P.430 that consists of fourteen homogeneous road sections on basis of the curvature change rate evaluation and administrative government. A total of 138 crashes with 246 injuries and 20 deaths were recorded in 2009−2013 on a total length of 73 km almost. According to Italian methodology based on the calculation of crash rates for homogeneous road sections, the crash levels have been associated with each study road section. It was observed that 79% of the sections are characterized by a low crash level and the remaining 21% by a severe crash level. S.P.430 road sections with a severe crash level are potential locations with speed control cameras. As speed control cameras are missing in S.P. 430, there si no a remarkable reduction in the number of the crashes during the years as happened in Lithuania by similar infrastructural, land context, driver speed behaviour features between two cases study

I-BIM for existing airport infrastructures

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RURAL ROAD REVERSE ENGINEERING USING BIM: AN ITALIAN CASE STUDY

The use of Building Information Modeling (BIM) is changing the way to perceive, manage and maintain any infrastructural project. The concept of Smart Roads relaunches the transport infrastructure sector through the digital transformation, able to create lean, quality, safer and cheaper infrastructures. The reverse engineering parametric modeling process was applied to “SS18 VAR” rural road, one of the main viabilities in Southern Italy. The case study was developed in according to the following steps: a) creating Digital Terrain Model (DTM); b) modeling horizontal alignment-vertical profiles; c) modeling 3D Corridor; d) modeling Viaducts; e) creating realistic 3D rendering. Bentley Systems software® were used in this study. The case study provided interesting elements to evaluate the advantages and disadvantages of design practice through BIM style tools, as well as the current state of the methodology itsel

Preliminary Study on Runway Pavement Friction Decay Using Data Mining

AbstractSurfaces of airport pavements are subject to the friction decay phenomenon. A recurrent problem for the runways is represented by the deposits of vulcanized rubber of aircraft tires. This happens mainly in the touch-down areas during landing operations, and the loss of grip compromises the safety of both take-off and landing operations. This study moves from the International Civil Aviation Organization and the Italian Civil Aviation Authority provisions concerning runway friction measurement and reporting to a better way to analyze friction data. Being data mining the computational process of discovering patterns in a large data sets, data mining techniques are very helpful to reach this target. Unsupervised and supervised classification methods to analyze friction data detected by Grip Tester Trailer were employed. First, K-means and Subtractive Clustering were applied to divide data into a certain number of clusters representing the different areas of consumption. In a second time two different Classification and Regression Trees models, CART and GCHAID, were employed to split the data points of the runway into nodes. At the end of the process scatterplots were built and better visualized through non-linear regressions. The decay curves obtained were of service to compare the results achieved using data mining techniques versus the International Civil Aviation Organization and the Italian Civil Aviation Authority provisions in order to find out the best way to analyze friction data. The final goals are to assure an optimum scheduling of the Airport Pavement Management System, as well as users safety

Verifying the Mechanical Performance of Cold and Hot Asphalt Mastics Containing Jet Grouting Waste as a Filler

In the road construction sector, the CO2 emissions that affect global warming are, in most cases, from the asphalt mixtures production activities that are carried out at high temperature (above 160 °C). The research here presented aims to investigate the physical-mechanical properties of asphalt mastics made up using jet grouting waste (JW) as a filler produced through both cold (40–50 °C) and hot mixing process. The first step focused primarily on examining the effects of optimal blending time and curing time of the mastics. The second step focused on the investigation of the rheological properties using a dynamic shear rheometer and carrying out a frequency sweep test at temperatures ranging from 0 to 50 °C with increments of 10 °C, and a multiple stress creep and recovery (MSCR) test under 0.1 and 3.2 kPa load levels at temperatures of 40 and 50 °C. Four cold asphalt mastic solutions were analyzed and then compared to three hot traditional ones, keeping constant, on the one hand, the binder weight and filler over binder weight ratio (0.5), and, on the other hand, changing the type and amount of filler. The compositions of the hot and cold asphalt mastics were as follows: (a) 33% limestone filler (LF) plus 67% bitumen (concerning the cold mixing process, the bitumen content refers to the amount of bitumen into the bitumen emulsion), (b) 33% JW plus 67% bitumen, (c) 16.5% LF plus 16.5% JW and 67% bitumen. The fourth solution designed only for cold asphalt mastic was made up of 33% Portland cement (PC) plus 67% bitumen (referring to the amount of bitumen in the bitumen emulsion). The main findings showed that the optimal performance was achieved at high test temperature by cold and hot asphalt mastics made up adding LF and JW filler, which showed a pronounced elastic behavior. Moreover, the cold asphalt mastic solution made up of LF and JW filler showed better performance than the mastic made up using PC, reaching over 40% increase of the shear modulus and 30% lower non-recoverable creep compliance values at all test temperatures

Additional procedures for characterizing the performance of recycled polymer modified asphalt mixtures

Great efforts have been made in recent years to improve the mechanical properties of asphalt mixtures by replacing conventional mix components with innovative ones or by adding materials such as polymers. Hence, the innovative-sustainable road materials to be investigated through laboratory tests require articulated procedures, the research here presented aims to provide an experimental-methodological approach to analyse the mechanical performance of untraditional hot asphalt mixtures made up using a polymer compound of recycled plastics. Three Asphalt Concrete 20 (AC20) Hot Asphalt Mixtures (HMA) were analysed by measuring base properties (i.e., indirect tensile strength and moisture damage) and advanced features (i.e., stiffness, fatigue, cracking and rutting resistance). As a result, the addition of polymer compound using dry process might lead firstly to change the laboratory mixing procedure than the traditional hot limestone asphalt solutions. The main benefits derived from the adoption of this innovative technology compared to the conventional ones are as follows: a) an improvement of resistance to moisture damage (at 15 ◦C); b) a suitable stiffness at 10, 20 and 40 ◦C; c) an increment of the cracking resistance (at 10 ◦C) and d) a good rutting resistance in terms of rut depth (at 60 ◦C)

BIM-LCA Integration Framework for Sustainable Road Pavement Maintenance Practices

The latest advancements in road asphalt materials and construction technologies have increased the difficulty for engineers to select the appropriate pavement design solution with consideration of life cycle assessment (LCA) methodology. On the other hand, infrastructure building information modeling (BIM) tools allow practitioners to efficiently store and manage large amounts of data, supporting decision making in road asphalt pavement design and management. This research contributes to setting up a dynamic LCA tool for the specific evaluation of designed road asphalt pavement solutions involving alternative materials and advanced recycling technologies; the tool is structured to minimize the need of input data by the designer, that are usually unknown during the early design stage, and automate the entire LCA calculation process to reduce the designer efforts and avoid any errors during data transcription. A traditional BIM workflow was integrated with additional user-defined property sets to simultaneously compute the environmental impact of the entire life cycle of the asphalt pavement, and dynamically update the result basing on the design thickness of the pavement layers, the specific features of materials and an external database of several life cycle impact category indicators that can be edited and updated gradually during more advanced design stage. The proposed BIM-LCA aims to be a practical and dynamic way to integrate environmental considerations into road pavement design, encouraging the use of digital tools in road industry and ultimately supporting a pavement maintenance decision-making process oriented toward circular economy

field measurements on runway friction decay related to rubber deposits

Surfaces of airport pavements are subject to contamination that can be very dangerous for the movement of aircraft particularly on the runway. A recurrent problem is represented by the deposits of vulcanized rubber of aircraft tires in the touchdown area during landings and lesser during take-offs. This causes a loss of grip that compromises the safety of aircraft movements in take-off and landing operations. This study deals with the surface characteristics decay phenomenon related to contamination from rubber deposits. The experiment was conducted by correlating the pavement surface characteristics, as detected by Grip Tester, to air traffic before and after de-rubberizing operation and two models were constructed for the assessment of functional capacity of the runway before and after the operations de-rubberizing