Ugo Spirito e la riforma penale italiana

Il tormentato interesse di Ugo Spirito per il diritto penale costituiva da sempre una costante, un punto di riferimento, - o, per meglio dire, di orientamento decisivo - per i suoi totalizzanti itinerari speculativi. La riflessione penalistica, per quell'eminente filosofo, era un fatto centrale, una scelta ineludibile. Come tale, essa continuava a costituire una sorta di fiume carsico che nel dipanarsi del suo pensiero, nel susseguirsi delle opere date alle stampe, periodicamente riaffiorava

On-site inspections of pavement damages evolution using GPR

Ground-penetrating radar (GPR) is being increasingly used for pavements maintenance due to the wide range of applications spanning from physical to geometrical inspections, thereby allowing for a reliable diagnosis of the main causes of road structural damages. In this work, an off-ground GPR system was used to investigate a large-scale rural road network. Two sets of surveys were carried out in different time periods, with the main goals to i) localize the most critical sections; ii) monitor the evolution of previous damages and localize newborn deep faults, although not revealed at the pavement surface level; iii) analyze the causes of both evolution and emergence of faults by considering environmental and human factors. A 1-GHz GPR air-launched antenna was linked to an instrumented van for collecting data at traffic speed. Other support techniques (e.g. GPS data logger, odometer, HD video camera) were used for cross-checking,. Such centre frequency of investigation along with a 25-ns time window allow for a signal penetration of 900 mm, consistent with the deepest layer interfaces. The bottom of the array was 400 mm over the surface, with a minimum distance of 1200 mm from the van body. Scan length of maximum 10 km were provided for avoiding heavy computational loads. The rural road network was located in the District of Rieti, 100 km north from Rome, Italy, and mostly develops in a hilly and mountainous landscape. In most of the investigated roads, the carriageway consists in two lanes of 3.75 meters wide and two shoulders of 0.50 meters wide. A typical road section includes a HMA layer (65 mm average thickness), a base layer (100 mm average thickness), and a subbase layer (300 mm average thickness), as described by pavement design charts. The first set of surveys was carried out in two days at the beginning of spring in moderately dry conditions. Overall, 320-km-long inspections were performed in both travel directions, thereby showing a productivity of approximately 160 km/day at 40 km/h speed, on the average. After processing and first-checking, GPR profiles were divided into homogeneous sections according to the combination of different parameters (e.g. route analyzed, long distance conditions of regularity/irregularity in layers arrangement). In such context, a high consistency between surface damages, mismatches from the GPR scans, and boundary environmental conditions was demonstrated. In addition, deep mismatches were detected even for early-stage or unrevealed faults. The second set of surveys was carried out in autumn in high humidity conditions, due to recent rainfalls. 160 km of relevant routes from the same road network were investigated. Results showed a high consistency with those collected during the first-stage of surveys. Minor changes were found in those sections with low traffic loads (e.g. farther away from the biggest town of Rieti), whereas major mismatches were detected in wetlands (e.g. close to rivers), work zones, and nearby those sections already deeply damaged in the past. This work benefited from networking activities carried out within the EU funded COST Action TU1208 “Civil Engineering Applications of Ground Penetrating Radar”

Efficient practices in railway ballast maintenance and quality assessment using GPR

The need for effective and efficient railway maintenance is always more demanded all over the world as the main consequence of aging and degradation of infrastructures. Primarily, the filling of air voids within a railway ballast track-bed by fine-grained materials, coming up from the subballast layers by vibrations and capillarity effects, can heavily affect both the bearing and the draining capacity of the infrastructure with major impacts on safety. This occurrence is typically referred to as “fouling”. When ballast is fouled, especially by clay, its internal friction angle is undermined, with serious lowering of the strength properties and increase of deformation rates of the whole rail track-bed. Thereby, a detailed and up-to-date knowledge of the quality of the railway substructure is mandatory for scheduling proper maintenance, with the final goal of optimizing the productivity while keeping the safety at the highest standard. This paper aims at reviewing a set of maintenance methodologies, spanning from the traditional and most employed ones, up to the most innovative approaches available in the market, with a special focus on the Ground Penetrating Radar (GPR) non-destructive testing (NDT) technique. The breakthrough brought by the application of new processing approaches is also analyzed and a methodological framework is given on some of the most recent and effective maintenance practices

Superdense galaxies and the mass-size relation at low redshift

We search for massive and compact galaxies (superdense galaxies, hereafter SDGs) at z=0.03-0.11 in the Padova-Millennium Galaxy and Group Catalogue, a spectroscopically complete sample representative of the local Universe general field population. We find that compact galaxies with radii and mass densities comparable to high-z massive and passive galaxies represent 4.4% of all galaxies with stellar masses above 3 X 10^10 M_sun, yielding a number density of 4.3 X 10^-4 h^3 Mpc^-3. Most of them are S0s (70%) or ellipticals (23%), are red and have intermediate-to-old stellar populations, with a median luminosity-weighted age of 5.4 Gyr and a median mass-weighted age of 9.2 Gyr. Their velocity dispersions and dynamical masses are consistent with the small radii and high stellar mass estimates. Comparing with the WINGS sample of cluster galaxies at similar redshifts, the fraction of superdense galaxies is three times smaller in the field than in clusters, and cluster SDGs are on average 4 Gyr older than field SDGs. We confirm the existence of a universal trend of smaller radii for older luminosity-weighted ages at fixed galaxy mass. On top of the well known dependence of stellar age on galaxy mass, the luminosity-weighted age of galaxies depends on galaxy compactness at fixed mass, and, for a fixed mass and radius, on environment. This effect needs to be taken into account in order not to overestimate the evolution of galaxy sizes from high- to low-z. Our results and hierarchical simulations suggest that a significant fraction of the massive compact galaxies at high-z have evolved into compact galaxies in galaxy clusters today. When stellar age and environmental effects are taken into account, the average amount of size evolution of individual galaxies between high- and low-z is mild, a factor ~1.6. (abridged)Comment: ApJ, in pres

Evaluation of the impact of pavement degradation on driving comfort and safety using a dynamic simulation model

The dynamic effects exerted by the vehicles on the road pavement have been thoroughly investigated over years. The main reason for this investigation is the major influence on the propagation and worsening of the pavement damages exerted by the dynamic loads rather than the static ones. To date, the modelling theories of systems have evolved, along with the computational capability of the modern calculators. To this effect, three-dimensional simulations of the tire-surface interaction are commonly used. These simulations take into account the dynamics of the load and the consequent deformation of the pavement. However, previous studies aimed at analyzing the above interaction for the optimisation strategies of the maintenance activities within the context of effective road asset management. On the contrary, this work focuses on the safety-related issues linked with the dynamic effects suffered by the vehicle, when passing on different road defects. The goal of this study is to analyse numerically the kinematic and the dynamic effects of the pavement degradations (and in particular rutting) on the driving safety. The simulation of the main characteristics and the evolution of the pavement damages over the time (e.g., the simulation of the tire-pavement contacts and the dynamic response on the vehicles) is a useful method for the development of safe and comprehensive rehabilitation programs. These are of paramount importance to limit the accident rates. The effects on the driving safety was analysed using a simulation model for the vehicles behaviour in the case of damaged pavements. Different road geometries and vehicle types were considered to evaluate the rutting effects on safety, as a function of the evolution stage of this type of pavement damage. In more detail, the performance characteristics of the vehicles, the dynamic and kinematic parameters (e.g., the vehicle trajectory and the vertical acceleration), were collected for pavement conditions with progressively high levels of rutting. The study proposes a theoretical model of qualitative relationships between differing stages and location of rutting, and the consequent effects on driving safety for different types of vehicles (passenger cars and powered two wheelers). It is worth to emphasize the relevance of this research for maintenance prioritization purposes at the road network level. Priority is based on the level of risk associated with the pavement degradations and with different types of vehicle

Prediction of rutting evolution in flexible pavement life cycle at the road network scale using an air-launched ground-penetrating radar system

In this work, the evolution of damages in pavement life cycle relative to rutting has been modeled in relevant pavement sections. Ground-penetrating radar (GPR) surveys were carried out at the rural road network scale using an air-launched pulsed radar system, 1GHz central frequency of investigation, linked to an instrumented van for collecting data at traffic speed. Surveys were performed in two time periods, six months apart from each other. By knowing the geometrical, traffic, climatic and construction information of each surveyed pavement section, and on the basis of comprehensive literature studies dealing with rutting versus time measurements in several flexible pavement sections during their life cycle, it has been possible to determine a reliable domain of existence by means of rutting versus time prediction curves, in which to locate the pavement section-specific prediction curve, case by case. Results have shown reliable relationships, wherein damage prediction is consistent with those suggested by literature

Good practices for the operational safety management in the early recovery phase of a seismic event using GPR

This study deals with a case report about the planning and the performance of GPR surveys carried out in the town of Amatrice, in the district of Rieti, Italy. As sadly known, the town has been hit by a 6.9 magnitude earthquake in the nighttime of August 24th 2016. The strength of the seism, along with the age and the deterioration rate of the structural asset, have caused the razing to the ground and the critical damaging of the majority of the buildings within the “red zone area”, corresponding to the historical town center. In the early recovery phase taking place afterwards, the strong seismic swarm subsequent the main shake has sensitively slowed down the rescue and rehabilitation operations. Moreover, the main issue was related to the unsafety operational conditions of volunteers and firemen. To this effect, the geotechnical stability of the roads and the large operational areas represented critical issues, as up to 40 tons crane trucks were needed to put in safety the highest buildings, such as three-floor buildings and historical towers. In this framework, ground-penetrating radar (GPR) provided a valuable help in preliminary assessing the stability of the areas where the crane trucks were planned to operate as well as to be parked over. The main objective of the GPR tests was to verify the absence of possible cavities beneath the ground surface that could undermine the strength of the surface under heavy loadings. To that effect, a multi-frequency ground-coupled GPR system was used. This radar system can simultaneously collect data at both the frequencies of 600 MHz and 1600 MHz. Four different sites were surveyed, namely, two sections of the main road passed on by the cranes, and two machinery depot areas down by the towers. In the former case, the surveys were performed by parallel longitudinal scans, due to the significant longitudinal length of the sections, whereas in the latter, two grids with differing sizes were realized and scanned for producing horizontal tomographic maps. In both the cases, useful insights have been pointed out, and relevant critical areas of possible weaknesses in the soil strength, where to focus further and more specialist analyses, have been detected. It is important to emphasize on the details provided about the working procedures in such a complex environment

Evaluation of the impact of pavement degradation on driving comfort and safety using a dynamic simulation model

The dynamic effects induced by vehicles on road pavement have been thoroughly analysed over years [1]. The main reason of such focus is the major influence exerted on the propagation and worsening of pavement damages by the dynamic loads rather than the static ones [2]. To date, the modelling theories of systems have evolved, along with the computational capability of modern calculators. To this effect, three-dimensional simulations of the tire-surface interaction [3, 4] are commonly used. The simulations take into account both the dynamics of the load and the consequent deformation of the pavement. However, previous studies aimed at analyzing the above interaction for the optimisation strategies of the maintenance activities within the context of effective road asset management. On the contrary, this work focuses on the safety-related issues by the dynamic effects suffered by the vehicle, when passing on different road defects. The goal of this study is to numerically analyse the kinematic and dynamic impacts of the pavement degradations (and in particular rutting) on the driving safety. The simulation of the main characteristics and evolution of the pavement damages over the time, such as the simulation of the tire-pavement contacts and the dynamic response on the vehicles, is a useful tool for developing safe and comprehensive rehabilitation programs. These are of paramount importance to limit the accident rates. The impact on driving safety was analysed using a simulation model for the simulation of the vehicles behaviour in the case of damaged pavements. Specifically, different road geometries and vehicle’s typologies were considered to evaluate the rutting effects on safety, as a function of the evolution stage of this pavement damage. In more detail, the performance characteristics of the vehicles, the dynamic and cinematic parameters (e.g. the vehicle trajectory and the vertical acceleration), were collected for increasingly rutted pavement conditions. The study proposes qualitative relationships between differing stages and location of rutting, and the consequent impacts on driving safety for different types of vehicles (passenger cars and powered two wheelers). It is important to emphasize how this analysis could be helpful to the road agencies in prioritizing maintenance actions on large-scale road assets. Prioritization will be mainly focused on the level of risk associated with pavement degradations

A Study on Driving Performance Along Horizontal Curves of Rural Roads

Several studies have indicated that road crashes are more likely to occur on horizontal curves than on straight roadway segments for a good number of reasons, the most important of which is associated with the driver's behaviour along the curve depending on his perception of the road geometry. However, the evaluation of the effects of curve features on driving performance still remains a critical issue for road safety and design. The main objective of this study is to investigate driver's behaviour and his perception of road curves, which is directly related to road safety. Specifically, the effects of some curve features (radius, transition curve, visibility, cross section) on driving performance are investigated through a multi-factorial experiment based on driving simulation. The driving speeds and trajectories of a sample of 34 drivers were statistically processed over 72 different curves distributed along three test scenarios. The main and interaction effects of the independent variables are described and discussed in the results section of this paper providing a significant improvement of the actual knowledge on in this field of research. In general, the results confirm that driving simulation can disclose the relationships between road design features and driver behavioural aspects that are crucial issues in creating a safer road infrastructure

A GPR investigation of railway ballast for signal noise filtering of railway sleepers effects

Ground-penetrating radar (GPR) has proven to be a very effective tool for the assessment and health monitoring of linear transport networks. To date, the use of this technology is well-established in highway engineering for the inspection of roads at the network level. This is mostly due to the high reliability of the available data processing algorithms and the relatively ease of interpretation of the GPR image outputs. Conversely, the use of GPR for railway inspections has been not widespread likewise. Among the possible causes for this gap, it is worthy of mention the high rate of disturbance created by sleepers and rails to the GPR signal. Indeed, reflections from these pieces of structural components – and particularly from their metallic parts – may reduce or totally affect the interpretation of the subsurface features. This paper evaluates the influence of concrete railway sleepers on the GPR signal collected to assess railway ballast conditions in a laboratory environment. More specifically, the main aim is to comprehend the disturbance given by these components for clean and fouled ballast. To this purpose, numerous GPR tests were carried out and a dedicated set-up was created. A methacrylate tank with dimensions of 1.5 m × 1.5 m × 0.50 m was filled up with limestone railway ballast aggregates, in both clean and polluted conditions. Hence, two concrete sleepers of standard dimensions were laid above the material. GPR tests were performed using 4 different air-launched antenna systems with frequencies of 1000 MHz, 1500 MHz and 2000 MHz (in both the standard and low-powered version). Each antenna system was oriented in two different ways, i.e. longitudinally and transversely with respect to the tracks orientation. A dedicated data processing scheme was used to filter out noise and unnecessary information from the signal. Investigations were made by way of comparison between the configuration with ballast material only and the configuration with ballast material and sleepers (in both clean and fouled conditions). Results demonstrated the viability of the proposed data processing scheme to single out the disturbance of sleepers to the GPR signal and a method to minimise the noise was also proposed. Acknowledgement The authors are sincerely grateful to Mr Spartaco Cera for the invaluable help during the GPR surveys