1,102 research outputs found

    Climate change and transport infrastructures: State of the art

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    Transport infrastructures are lifelines: They provide transportation of people and goods, in ordinary and emergency conditions, thus they should be resilient to increasing natural disasters and hazards. This work presents several technologies adopted around the world to adapt and defend transport infrastructures against effects of climate change. Three main climate change challenges have been examined: Air temperatures variability and extremization, water bombs, and sea level rise. For each type of the examined phenomena the paper presents engineered, and architectural solutions adopted to prevent disasters and protect citizens. In all cases, the countermeasures require deeper prediction of weather and climate conditions during the service life of the infrastructure. The experience gained supports the fact that strategies adopted or designed to contrast the effects of climate change on transport infrastructures pursue three main goals: To prevent the damages, protect the structures, and monitor and communicate to users the current conditions. Indeed, the analyses show that the ongoing climate change will increase its impact on transport infrastructures, exposing people to unacceptable risks. Therefore, prevention and protection measures shall be adopted more frequently in the interest of collective safety

    Prioritization methodology for roadside and guardrail improvement: Quantitative calculation of safety level and optimization of resources allocation

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    The attention to road safety-related issues has grown fast in recent decades. The experience gained with these themes reveals the importance of considering these aspects in the resource allocation process for roadside and guardrail improvement, which is a complex process often involves conflicting objectives. This work consists on defining an innovative methodology, with the objective of calculating and analysing a numerical risk factor of a road. The method considers geometry, accident rate, traffic of the examined road and four categories of elements/defects where the resources can be allocated to improve the road safety (safety barriers, discrete obstacles, continuous obstacles, and water drainage). The analysis allows the assessment of the hazard index, which could be used in decision-making processes. A case study is presented to analyse roadsides of a 995 km long road network, using the cost-benefit analysis, and to prioritize possible rehabilitation work. The results highlighted that it is suitable to intervene on roads belonging to higher classes of risk, where it is possible to maximize the benefit in terms of safety as consequence of rehabilitation works (i.e., new barrier installation, removal and new barrier installation, and new terminal installation). The proposed method is quantitative; therefore, it avoids providing weak and far from reliable results; moreover, it guarantees a broad vision for the problem, giving a useful tool for road management body

    Road safety analysis of urban roads. Case study of an Italian municipality

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    Attention to the most vulnerable road users has grown rapidly over recent decades. The experience gained reveals an important number of fatalities due to accidents in urban branch roads. In this study, an analytical methodology for the calculation of urban branch road safety is proposed. The proposal relies on data collected during road safety inspections; therefore, it can be implemented even when historical data about traffic volume or accidents are not available. It permits us to identify geometric, physical, functional, and transport-related defects, and elements which are causal factors of road accidents, in order to assess the risk of death or serious injuries for users. Traffic volume, average speed, and expected consequences on vulnerable road users in case of an accident allow us to calculate both the level of danger of each homogeneous section which composes the road, and the hazard index of the overall branch. A case study is presented to implement the proposed methodology. The strategy proposed by the authors could have a significant impact on the risk management of urban roads, and could be used in decision-making processes to design safer roads and improve the safety of existing roads

    Comparative life cycle assessment of lighting systems and road pavements in an Italian twin- tube road tunnel

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    This work calculates and discusses the Life Cycle Assessment (LCA) of four scenarios composed of two types of road pavements and two types of lighting systems to be built in an Italian twin-tube road tunnel. A 20-year time horizon is adopted to assess the burdens of construction and maintenance of both flexible and rigid pavements and high-pressure sodium (HPS) and lightemitting diode (LED) lamps, traffic, and switching on of lamps. All considered scenarios are comparable with each other in terms of technical performances, but significantly differ regarding their environmental consequences. The geometrical and technical characteristics of the examined scenarios comply with current Italian standards for highways. In all the examined cases, LCA is carried out according to the European standard, EN 15804, and includes 19 impact categories (IC). The analysis demonstrates that the use of more reflecting surface pavement materials (i.e., concrete vs. asphalt) and more performing lighting systems (i.e., LED vs. HPS) can effectively mitigate the deleterious burdens related to road construction, maintenance, and use. For most of the examined ICs, the most environment-friendly scenario has LED lamps and concrete pavement

    Airport veer-off risk assessment: An italian case study

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    The objective of this paper is to assess the veer-off risk of an Italian airport that is characterized for having near 12,000 annual movements. The name of this airport is not disclosed for security purposes. The methodology used followed the principles of probabilistic risk analysis in order to characterize the events and assess the corresponding damages. The study used statistical data about accident reports and local conditions that were collected following the standards of the International Civil Aviation Organization (ICAO). The methodology used in this work complies with the guidelines for the adjustment of lateral runway strips, edited by the Italian Civil Aviation Authority (ENAC). Besides, data available in worldwide databases of airplane accidents were also gathered and included as part of the analysis. The method used to assess the veer-off risk of the airport is consistent with probability and damage quantification methods published in the literature. The main variables considered in the analysis were traffic information, wind conditions, the existence of landsidebuildings adjacent to the runway, and the geotechnical conditions of the subgrade underneath the strip zones. For the assessment of the veer-off risk, the authors used primary data provided by the airport management body within the period 2013-2015 and secondary data available in the literature. The risk of veer-off was calculated in more than 1,500 points around the runway. Besides, the authors proposed maximum allowable risks in different locations, and these values were compared to the actual risk levels previously computed. The results of this comparison suggested that improvements in the soil capacity and/or in the airport management activities might contribute to achieve the proposed allowable risk. The results from this assessment showed that the two critical variables determining the risk of veer-off accidents in the airport under evaluation were wind conditions and the bearing capacity of the soil underneath the strip areas. Also, it was found that the highest veer-off risk level obtained within the Cleared and Graded Area (CGA, part of the runway strip cleared of all obstacles and graded) was 2 10-7, while the lowest level was 3 10-8, which are considered typical risk ranges in airport operations. In general, the results demonstrate that the adopted methodology is a useful tool to evaluate the veer-off risk of a specific airport. Besides, the method allows comparing the actual levels of risk with proposed target levels of safety.Consequently, the quantification of the veer-off risk levels offers the airport management body the possibility of implementing appropriate measurements in those cases where minimum safety requirements are not achieved

    Technical and Economic Criteria to Select Pavement Surfaces of Port Handling Plants

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    A port is an intermodal system in which many logistics activities requiring properly constructed areas occur. The large extension of these areas poses a major problem in choosing materials with technical and economic implications. Choice and design of pavements are directly related to the port handling systems and procedures for the disposal of the cargo units. The paper presents the design and verification procedures for three equivalent pavements for a handling pavement in an Italian medium-sized port trafficked by reach stackers moving containers. An asphalt pavement, a concrete pavement, and a concrete block pavement have been considered during the 20-year service life. Empirical and analytical methods have been adopted to design and verify the pavements. The structures have been examined in terms of economic concerns during the overall service life, considering both construction and maintenance costs, in order to determine the most cost-effective option. The results demonstrate the inappropriateness of asphalt pavement, in the examined case, from a construction costs point of view. Furthermore, the overall discounted costs show an inversion of convenience between block concrete pavement and cast in situ concrete: the latter is the cheaper solution. The proposed methodology can balance often conflicting objectives in matters of durability and funds management, providing answers to a complex topic

    Safety problems in urban cycling mobility. A quantitative risk analysis at urban intersections

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    The attention to the most vulnerable road users has grown rapidly in recent decades. The experience gained reveals an important number of cyclist fatalities due to road crashes; most of which occur at intersections. In this study, dispersion of trajectories in urban intersections has been considered to identify the whole conflict area and the largest conflict areas between cars and bicycles, and the speeds have been used to calculate exposure time of cyclists and reaction time available to drivers to avoid collision. These data allow the summary approach to the problem, while a risk probability model has been developed to adopt an elementary approach analysis. A quantitative damage model has been proposed to classify each conflict point, and a probabilistic approach has been defined to consider the traffic volume and the elementary unit of exposure. The combination of damage and probability, permitted to assess the risk of crash, at the examined intersection. Three types of urban four-arm intersection, with and without bike paths, were considered. For each scheme, the authors assessed the risk of collision between the cyclist and the vehicle. The obtained results allowed the identification of the most hazardous maneuvers and highlighted that geometry and kinematics of traffic movements cannot be overlooked, when designing an urban road intersection. The strategy proposed by the authors could have a significant impact on the risk management of urban intersections. The obtained results and the proposed hazard estimation methodology could be used to design safer intersections

    Railway freight transport and logistics: Methods for relief, algorithms for verification and proposals for the adjustment of tunnel inner surfaces

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    In Europe, the attention to efficiency and safety of international railway freight transport has grown in recent years and this has drawn attention to the importance of verifying the clearance between vehicle and lining, mostly when different and variable rolling stock types are expected. This work consists of defining an innovative methodology, with the objective of surveying the tunnel structures, verifying the clearance conditions, and designing a retrofitting work if necessary. The method provides for the use of laser scanner, thermocameras, and ground penetrating radar to survey the geometrical and structural conditions of the tunnel; an algorithm written by the authors permits to verify the clearances. Two different types of works are possible if the inner tunnel surfaces interfere with the profile of the rolling stock passing through: modification of the railroad track or modification of the tunnel intrados by mean milling of its lining. The presented case study demonstrates that the proposed methodology is useful for verifying compatibility between the design vehicle gauge and the existing tunnel intrados, and to investigate the chance to admit rolling stocks from different states. Consequently, the results give the railway management body a chance to perform appropriate measurements in those cases where the minimum clearance requirements are not achieved

    Hip joint hydatidosis after prosthesis replacement

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    Summary Hydatidosis is a rare parasitic disease caused by the Echinococcus tapeworm, which only occasionally affects the musculoskeletal tissues. In this article we describe the case of a patient who underwent a total hip replacement procedure for a pathological fracture of the femur neck. At the next histological examination it was shown to be a consequence of secondary bone hydatidosis. This clinical case is exceptional in that the infection spread to the cotyloid and femoral prosthesis components and, in the following years, caused repeated episodes of joint dislocation

    Frequency of hypertension in hospitalized population with osteoporotic fractures: Epidemiological retrospective analysis of Hospital Discharge Data in the Apulian database for the period 2006–2010

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    Osteoporosis and hypertension are two widespread diseases, which share many of the same risk factors such as advanced age, early menopause, smoking, and physical inactivity. The aim of this study is to examine the association between fragility fractures, anti-hypertensive drugs (subgroup C02, according to the Anatomical Therapeutic Chemical classification system [ATC]), diuretics (subgroup C03), b-blocker (subgroup C07), calcium antagonist (subgroup C08) and renin-angiotensin-aldosterone system regulator (subC09), and drugs administration for osteoporosis among the osteoporotic population of a region of Southern Italy. We retrospectively studied “Hospital Discharge Data” (HDD) in the Apulian database for the period 2006–2010 to find fragility fractures treated with hospitalization in men aged over 65 years and in women aged over 50 years. We then checked the database for drug prescriptions to identify those patients who had taken at least one osteoporosis drug. Within this latter group, based on hospital admissions and prescription records, we identified the patients affected with hypertension. We observed that, between 2006 and 2010, in Apulia, 177,639 patients were hospitalized and diagnosed as having fragility fractures. The prevalence of hypertension patients in Apulia in this period was estimated at 44.3%. In the same region and period, the prevalence of patients with fragility fracture, who also had hypertension, was 80.9%. The percentage of fracture was lowest in the female population aged 50–59 years (52.5%), while the highest was in women aged > 80 years (92.5%). We observed that in hypertensive patients the most frequent site of fracture was the femur (43,638 cases), while the least frequent were the tarsus and metatarsus (742 cases combined). The patients who took angiotensin-converting enzyme (ACE) inhibitor and diuretic drugs presented a higher number of fragility fractures, while the calcium antagonists, beta-blockers, and ATC anti-hypertensive drugs were linked to a reduced incidence of lesions. Hypertension is associated with increased fracture risk in the Apulia population. The bone demineralization effect of this disease should be taken into account during the management of these patients. The different distribution of fragility fractures in relation to anti-hypertensive treatment warrants further investigatio
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