We present the GPR results dealing with flexible road pavements located on cut and fill sections with retaining wall. The aim is to evaluate the road damage (particularly the ramified cracks) taking into consideration also other parameters (cut and fill section height and traffic load). The GPR evaluation was carried out on 20 sites selected in the secondary urban road network of L’Aquila, a medium-size urban area representative of the Abruzzi Region (Central Italy). Stress induced by traffic load generally affects a road section thickness of about 1.0 m from the ground; so a monostatic GPR antenna, with a nominal frequency of 2000 MHz, was used given that its maximum inspection depth corresponds to 1.0 m from the ground. The 2000 MHz antenna has also a quite high-resolution when inspecting road damage. The GPR acquisition was carried out in damaged and adjoining undamaged road sites, to compare the GPR data of the two areas. GPR data analysis was based on the sweep-rectified power approach to evaluate the radar signal attenuation curve vs. depth, which permitted us to single out different road types of damage and to discuss the factors which caused them.

Mycorrhizal symbiotic plants, soil suitability, temperature, and humidity are, by general consensus, considered decisive factors in truffle production. However, experimental approaches to define the environmental conditions that stimulate formation of truffle primordia and promote their growth to maturity have been lacking. By analysis of data of many atmospheric and soil parameters collected since 2009 within a Tuber melanosporum orchard, the trends of metabolic activity, detected as CO2 production in the soil, have been identified as the most reliable parameter to indicate the ‘birth’ of the truffle primordia. They seem to be produced when mycelial activity is intense and undergoes water stress, after which it resumes. About 6–18 days after recovery of metabolic activity, we could collect primordia of T. melanosporum. Many die or develop too early and consequently rot or are eaten by insect larvae. These events occur several times during summer and autumn, those that ‘sprout’ in late summer or later grow steadily and reach maturity. Using a particular ground-penetrating radar (GPR) setup to discriminate truffles, we could identify individual truffles in the soil after they have enlarged to at least 6 mm in diameter and follow their growth in volume and diameter over time. These two instrumental methods (CO2 sensor and GPR), although yet to be improved, open new important perspectives to better understand truffle biology and manage truffle orchards to support the newly acquired demonstration of the fundamental role of host plants for the nutrient transfer to the ectomycorrhiza-mycelium-fruiting body complex of T. melanosporum.

The present research deals with a measure of the uranium contents of the soil Fe/Mn nodules in order to assess the relationship between uranium content of nodules and trace elements distribution in the bulk soil. Fe/Mn nodules were collected from B-horizons of 50 palaeosoils (mainly Alfisols and Ultisols) from Tuscany and Abruzzo Regions and their alpha natural radioactivity measured by autoradiography method. Results revealed that U tends to concentrate into Fe/Mn nodules without relation with the degree of soil evolution but clearly conditioned by the parent material composition of soils. Its concentration in a single nodule can be 2 or 3 times greater than values obtained for the bulk of palaeosoils of the same area. Moreover it was possible to highlight some interesting relationships between uranium content and the frequency of soil trace elements that could suggest the existence of Fe/Mn nodules with different micro chemical composition.

A high frequency GPR survey was carried out on degraded flexible road pavements built on embankments. The survey was expected to find correlations between types of damage, height of embankments, traffic load and GPR scan results. Five types of damages observed in twenty sites selected in L'Aquila (central Italy), were investigated: transversal and longitudinal cracks, only longitudinal cracks, only transversal cracks, ramified cracks and failures. To define the impact of embankment height and traffic load on road pavement degradation, the survey focused on high and low embankments, as well as on heavy and low traffic road pavements. Road integrity was evaluated by a quantitatively analysis (GPR signal attenuation vs. depth), using a 1600 MHz handheld shielded monostatic bow tie antenna. It investigates media, with a resolution of about 1 cm, till a depth of 1.5 m which is also the maximum depth of influence of the induced traffic stress.

The findings of a GPR survey carried out on damaged flexible road pavements built on embankments and in cutting sections were reported. The survey was carried out to recognize correlations between: (i) types of damage, (ii) height of embankments or depth of cutting sections, (iii) traffic load and (iv) GPR scan results. Two types of damages, inducing loss of load bearing capacity, were investigated: transversal cracks and ramified cracks. Sixteen sites were chosen, describing the different combinations of the variables to be analyzed. The sites were selected among secondary non-urban roads in the area of L'Aquila (central Italy). Road integrity was evaluated by a GPR quantitative analysis (GPR signal attenuation vs. depth), using an antenna array with a nominal frequency of 1600 MHz. It investigates media till a depth of 1.5 m which is also the maximum depth of influence of the induced traffic stress. The results carried out from two sets of scans (affected and unaffected parts) were compared in order to identify GPR signal changes. These changes made it possible to trace the causes of the damage to the road pavement vs. embankment height, cutting depth and traffic load.

Structural degradation of road pavements has a considerable impact on traffic safety. Roadway surface defects or discontinuities make driving uncomfortable and increase chances of accidents. GPR is an effective and non-destructive technique to discover and trace the causes of road pavement damages so characterizing road integrity. The paper shows the findings of a GPR survey carried out on degraded road pavements built in cutting sections. The survey was expected to find correlations between: (i) types of damage, (ii) depth of cutting sections, (iii) traffic load and (iv) GPR scan results. Five types of damages, inducing loss of load bearing capacity, were investigated: (i) transversal and longitudinal cracks, (ii) only longitudinal cracks, (iii) only transversal cracks, (iv) ramified cracks and (v) failures. To determine the impact of cutting depth and traffic load on road pavement degradation, the survey focused on high (depth > 4 m) and low (depth < 2 m) cuttings, as well as on heavy traffic (average daily traffic > 4000) and low traffic (average daily traffic < 1000) road pavements. Twenty sites were chosen in the area of L’Aquila (central Italy), describing the different combinations of the variables to be analysed. Road integrity was evaluated by a GPR quantitatively analysis (GPR signal attenuation vs. depth), using a 1600 MHz antenna. It investigates media till a depth of 1.5 m which is also the maximum depth of influence of the induced traffic stress. GPR scans were first made on the degraded part of the road and then extended to its nearby unaffected part. The results carried out from the two sets of scans (affected and unaffected parts) were compared in order to identify GPR signal changes. These changes made it possible to trace the causes of the damage to the road pavement vs. cutting depth and traffic load.

Inappropriate use of agricultural, pasture, and woodlands are the main causes of soil degradation in many Mediterranean mountainous regions. Monitoring by remote sensing and other techniques are needed in order to map and control the land degradation. The study area is located in the Gran Sasso Massif (Central Italy), a typical Mediterranean calcareous area. The extreme reduction in soil thickness reduces water availability for vegetation, with a further stress condition added during summer droughts. The aim of this study was to investigate drought using soil survey information and hydraulic conductivity values to produce a soil dryness map. Soil influence on green biomass was assessed by the relationship of soil depth versus NDVI (a vegetation index derived by Landsat-TM data). The integrated approach of field and remote sensing data showed the existence of a link between soil moisture conditions and biomass production. Such correlations may be used in research on Mediterranean mountainous sub-arid areas.

Ground penetrating radar (GPR) surveys were applied in the preliminary stage of a project of structural monitoring and restoration of the facade of the Collemaggio Basilica, a medieval church located in L'Aquila (central Italy). GPR surveys were very useful in evaluating the state of conservation of the facade and in identifying the thickness of its walls, the forms and deterioration of its masonry with its ashlar facing and rubble core, and the forms and locations of its middle cornice supports. GPR was demonstrated to be an ideal non-destructive method to investigate ancient structures of high cultural and historical value. (C) 2004 Elsevier SAS. All rights reserved.

Planning of restoration works on degraded buildings should be preceded by collection of detailed data on their engineering, geotechnical and geophysical characteristics. These data should concern the design of the building, its structural features and foundations, as well as the geotechnical and geological characteristics of the soil and rock formations interacting with its foundations. Moreover, if the building has instability problems (settlements, slope failure, seepage, soil collapse, sink-holes, etc.) or has an "old age" (oxidization of reinforcing steel bars, masonry degradation), data acquisition should be as non-destructive as possible, fast and extend all over the investigated area. In the data acquisition stage, non-destructive methods, such as Ground Penetrating Radar, are very useful and in many cases absolutely necessary, as demonstrated in the two case studies presented here. Geophysical and geological investigations were carried out on two buildings located in L'Aquila and Chieti (Central Italy) which have undergone strong differential settlements. These phenomena caused widespread damages, which were mitigated by consolidation works. For the planning of these works, GPR, and geological surveys were performed in the area. GPR investigations (1600, 600 and 100 MHz frequency monostatic type antennas and 300 MHz frequency borehole antenna) enabled to determine the actual size, depth and location of the types of foundation and of underground infrastructures. Wells and local geological and structural survey and excavations allowed to integrate and to calibrate the GPR data.

A new unshielded low-frequency GPR antenna, centred on a frequency of about 40 MHz, has been recently developed by IDS Ingegneria dei Sistemi Spa, a leading Italian GPR manufacturer. The antenna is being tested. The Engineering Geology Laboratory of the L'Aquila University, with consolidated experience in GPR investigations, used it on two karst areas of central Italy, where available underground data were compared to GPR results, thus verifying depth and accuracy of the new antenna. The study areas were: i) the Lepini karst massif, characterized by diffuse underground caves and karst conduits (for which detailed speleological and geological data were available); and ii) the Gran Sasso Massif, with well-developed surficial karst morphologies (for which geological data were also available). GPR data on the latter study area were also provided by another IDS antenna with a central frequency of 100 MHz (maximum investigation depth: about 10 m). The radar time window was set to 640 ns, implying a maximum penetration depth of about 30 m at a standard propagation velocity of 10 cm/ns. In the Lepini massif, the depth of some strong anomalies, due to the occurrence of known caves, was in good agreement with the location obtained from speleological surveys. On the Gran Sasso Massif, data from the new 40 MHz antenna were compared to those recorded with the 100 MHz antenna, showing that the prototype is a very powerful tool to investigate deep cave and karst morphology.

Analysis and mapping of spring water temperature and el. conductivity data series can give insight into groundwater flowpaths, in areas where it is difficult to reconstruct the piezometric surface, a case in point being the fissured karst aquifer of the Gran Sasso massif, Central Italy. During the hydrogeological study of the Gran Sasso karst aquifer, greater understanding of the regional groundwater circulation was acquired through the statistical analysis of physico-chemical data collected in the 1970s, in the early 1980s and in the past four years. Maps were built of the temperature and el. conductivity trends of local spring waters, from the core to the borders of the aquifer. The maps helped refine the conceptual model of the fissured-karst aquifer, which had been developed on the basis of hydrogeological setting and discharge data. New hypotheses were formulated on the relationships between recharge and discharge areas and on real groundwater flowpaths.

During the hydrogeological study of the Gran Sasso karst aquifer, typical of the Mediterranean area, new insights were gained on regional groundwater circulation through statistical analysis of physicochemical data sets. The Gran Sasso carbonate aquifer, laterally confined by impermeable sediments, has a high recharge, due to tectonic pattern, climate and karst features. The springs of the Gran Sasso may be divided into 6 groups. These springs, which drain the massif, have an average discharge of about 18 m(3)/s. The construction of two highway tunnels obviously interfered with and involved many changes in this hydrogeological setting. The processing of temperature and resistivity/conductivity data sets showed significant differences between the springs. These findings suggest that the conceptual model of the aquifer, developed on the basis of hydrogeological and discharge data, should be redefined and that new chemical studies should be planned.