Advanced distributed modelling of slope stability using root reinforcement and geostatistical parameterization of geotechnical soil properties

2020 ◽  
Author(s):  
Elena Benedetta Masi ◽  
Anita Stagnozzi ◽  
Silvia Stagnozzi ◽  
Gianluigi Tonelli ◽  
Francesco Veneri ◽  
...  
Keyword(s):  
Slope Stability ◽  
Central Italy ◽  
Image Interpretation ◽  
Test Site ◽  
Rain Gauge ◽  
Rainfall Event ◽  
Unit Weight ◽  
Future Research ◽  
Time Step ◽  
Soil Thickness

<p>A physically based model for shallow landslide triggering (HIRESSS – HIgh REsolution Soil Stability Simulator) was applied in a 100 km<sup>2</sup> test site in Central Italy (Urbino, Marche region). The objectives were assessing  the influence of additional cohesion provided by roots and testing the effectiveness of a geotechnical characterization performed in an another area, but on similar lithologies.</p><p>We performed two different simulations considering the rainfall event of January-February 2006, which triggered 14 landslides in the area. For both the simulations, rainfall data were fed into the model using the measurements at hourly time step of a nearby rain gauge station, while soil thickness was estimated using a state-of-the-art empirical model based on geomorphological parameters derived from curvature, slope gradient, lithology and relative position within the hillslope profile. Geotechnical input data were varied among the two simulations. In the first one, a few in-situ and laboratory tests were performed to characterize the main lithologies, while the remaining lithologies were characterized using literature data. In the second simulation, the main geotechnical and hydrological parameters (cohesion, internal friction angle, soil unit weight, hydraulic conductivity) were fed into the model using a geostatistical characterization performed on hundreds of measurements carried out in another Italian region, with similar lithologies. Furthermore, in the second simulation the additional cohesion provided by the plant roots was also taken into account.</p><p>The results obtained with the two simulations were validated considering the landslide dataset collected by field work and image interpretation shortly after the rainfall event studied. We discovered that the second simulation provided much more reliable results, with the areas surrounding the landslide locations characterized by much higher values of failure probability.</p><p>The outcome is very important to address future research in distributed slope stability modelling because it proved that: (i) additional root cohesion is an important factor that can be used to get more reliable results; (ii) when in need of characterizing the geotechnical parameters of the study area, instead of using just a few measurements performed therein, it is preferable to integrate also data coming from different areas but with similar lithologies if they were robustly characterized in geostatistical terms purposely for distributed slope stability studies.</p>

scholarly journals Molecular Identification of New Cases of Human Dirofilariosis (Dirofilaria repens) in Italy

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 251
Author(s):  
Simona Gabrielli ◽  
Valentina Mangano ◽  
Federica Furzi ◽  
Alessandra Oliva ◽  
Serena Vita ◽  
...  
Keyword(s):  
Molecular Diagnosis ◽  
Central Italy ◽  
Research Work ◽  
Pulmonary Nodules ◽  
Elisa Test ◽  
Future Research ◽  
Worldwide Distribution ◽  
Human Dirofilariosis ◽  
Vector Borne ◽  
Etiological Agents

(1) Dirofilariosis is a vector-borne parasitic disease mainly in domestic and wild carnivores caused by Dirofilaria (Noctiella) repens, which is endemic in many countries of the Old World, and D. immitis, which has a worldwide distribution. In recent years, an increase in the number of human cases has been reported, suggesting that dirofilariosis is an emergent zoonosis. Here, we describe further cases (N = 8), observed in Central Italy during the years 2018–2019. (2) Molecular diagnosis was performed on: (i) live worms extracted from ocular conjunctiva, cheek, and calf muscle; (ii) histological sections of surgically removed nodules from parenchymal lung, coccyx, and breast. (3) Sequence analysis (650-bp) of the mitochondrial cytochrome oxidase subunit I gene (mtDNA cox1) showed a match of 100% with the sequences of D. repens previously deposited in GenBank. ELISA test to detect IgG against filarial antigens was performed on four patients’ sera and resulted positive in two patients who showed ocular and subcutaneous dirofilariosis, respectively. Microfilariae have been never detected in the peripheral blood of the patients. (4) The occurrence of N = 8 new cases of human D. repens-infections observed in a two-year period suggests an increased circulation of the parasite in Italy. Therefore, dirofilariosis should be included in differential diagnosis in patients presenting subcutaneous and/or pulmonary nodules. Molecular diagnosis of the etiological agents is fundamental. Specific serological diagnosis needs to be improved in future research work.

Identifying Cable Tension Loss and Deck Damage in a Cable-Stayed Bridge Using a Moving Vehicle

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Shih-Hsun Yin ◽  
Chung-Yu Tang
Keyword(s):  
Computational Study ◽  
Vertical Displacement ◽  
Relative Displacement ◽  
Future Research ◽  
Integration Scheme ◽  
Time Step ◽  
Cable Tension ◽  
Displacement Response ◽  
Cable Stayed Bridge ◽  
Response Vector

This paper presents a computational study on a new method of detecting multiple simultaneous damages in a cable-stayed bridge by use of the analysis of the vertical dynamic response of a vehicle passing the bridge. First, the study uses a finite-element method to simulate the vehicle cable-stayed bridge system. Then, the vertical vibration interaction between the bridge and the vehicle is solved by a time-step integration scheme. In this research, we consider that two kinds of damage including cable tension loss and deck damage may occur simultaneously at different locations. The differences between the vertical displacement responses of a vehicle passing the damaged bridge and the healthy bridge are sampled and called the relative displacement response vector of the vehicle. The proper orthogonal decomposition (POD) is utilized to decompose the relative displacement response vector of the vehicle passing the bridge with unknown multiple damages into an optimal set of basis vectors formed from the ones of the vehicle moving over the known damaged bridges. The associated system parameters variation with the unknown multiple damages can be reconstructed further. Discussions are given concerning the feasibility and limitation of the proposed detection technique as well as directions for future research.

scholarly journals Optimization of Rain Gauge Networks for Arid Regions Based on Remote Sensing Data

2021 ◽  
Vol 13 (21) ◽  
pp. 4243
Author(s):  
Mona Morsy ◽  
Ruhollah Taghizadeh-Mehrjardi ◽  
Silas Michaelides ◽  
Thomas Scholten ◽  
Peter Dietrich ◽  
...  
Keyword(s):  
Arid Regions ◽  
Flash Flood ◽  
Primary Source ◽  
Remote Sensing Data ◽  
Test Site ◽  
Rain Gauge ◽  
Cumulative Distribution ◽  
Climatic Data ◽  
Empirical Cumulative Distribution Function ◽  
Rain Gauges

Water depletion is a growing problem in the world’s arid and semi-arid areas, where groundwater is the primary source of fresh water. Accurate climatic data must be obtained to protect municipal water budgets. Unfortunately, the majority of these arid regions have a sparsely distributed number of rain gauges, which reduces the reliability of the spatio-temporal fields generated. The current research proposes a series of measures to address the problem of data scarcity, in particular regarding in-situ measurements of precipitation. Once the issue of improving the network of ground precipitation measurements is settled, this may pave the way for much-needed hydrological research on topics such as the spatiotemporal distribution of precipitation, flash flood prevention, and soil erosion reduction. In this study, a k-means cluster analysis is used to determine new locations for the rain gauge network at the Eastern side of the Gulf of Suez in Sinai. The clustering procedure adopted is based on integrating a digital elevation model obtained from The Shuttle Radar Topography Mission (SRTM 90 × 90 m) and Integrated Multi-Satellite Retrievals for GPM (IMERG) for four rainy events. This procedure enabled the determination of the potential centroids for three different cluster sizes (3, 6, and 9). Subsequently, each number was tested using the Empirical Cumulative Distribution Function (ECDF) in an effort to determine the optimal one. However, all the tested centroids exhibited gaps in covering the whole range of elevations and precipitation of the test site. The nine centroids with the five existing rain gauges were used as a basis to calculate the error kriging. This procedure enabled decreasing the error by increasing the number of the proposed gauges. The resulting points were tested again by ECDF and this confirmed the optimum of thirty-one suggested additional gauges in covering the whole range of elevations and precipitation records at the study site.

scholarly journals Application of Harmony Search Algorithm to Slope Stability Analysis

Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1250
Author(s):  
Sina Shaffiee Haghshenas ◽  
Sami Shaffiee Haghshenas ◽  
Zong Woo Geem ◽  
Tae-Hyung Kim ◽  
Reza Mikaeil ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Slope Stability ◽  
Safety Factor ◽  
Search Algorithm ◽  
Limit Equilibrium ◽  
Harmony Search ◽  
Harmony Search Algorithm ◽  
Slope Stability Analysis ◽  
Unit Weight ◽  
Slope Safety

Slope stability analysis is undoubtedly one of the most complex problems in geotechnical engineering and its study plays a paramount role in mitigating the risk associated with the occurrence of a landslide. This problem is commonly tackled by using limit equilibrium methods or advanced numerical techniques to assess the slope safety factor or, sometimes, even the displacement field of the slope. In this study, as an alternative approach, an attempt to assess the stability condition of homogeneous slopes was made using a machine learning (ML) technique. Specifically, a meta-heuristic algorithm (Harmony Search (HS) algorithm) and K-means algorithm were employed to perform a clustering analysis by considering two different classes, depending on whether a slope was unstable or stable. To achieve the purpose of this study, a database made up of 19 case studies with 6 model inputs including unit weight, intercept cohesion, angle of shearing resistance, slope angle, slope height and pore pressure ratio and one output (i.e., the slope safety factor) was established. Referring to this database, 17 out of 19 slopes were categorized correctly. Moreover, the obtained results showed that, referring to the considered database, the intercept cohesion was the most significant parameter in defining the class of each slope, whereas the unit weight had the smallest influence. Finally, the obtained results showed that the Harmony Search algorithm is an efficient approach for training K-means algorithms.

Conclusions

2015 ◽  
Author(s):  
Charlotte R. Potts
Keyword(s):  
Iron Age ◽  
Building Materials ◽  
Central Italy ◽  
Future Research ◽  
Main Body ◽  
Monumental Architecture ◽  
Form And Function ◽  
Religious Buildings ◽  
Religious Architecture ◽  
And Function

This book began by stating that histories of religious architecture can be accounts of both buildings and people. This particular history, focused on the archaeological evidence for the development of cult buildings in early central Italy, has reconsidered traditional narratives about the form and function of Etrusco-Italic religious architecture and proposed an alternative reconstruction of how their architects and audiences may have interacted with one another in Rome, Latium, and Etruria between the ninth and the sixth centuries BC. Comparison with the construction of monumental temples elsewhere also indicated that settlements including Rome, Satricum, Pyrgi, and Tarquinia can perhaps be considered part of a network of Archaic Mediterranean settlements with material, commercial, and religious connections, and that monumental architecture may have been a mechanism for successful social interaction. This study has therefore supported the suggestion that the physical and social fabric of ancient communities were closely linked, and that regional studies of Latium and Etruria may furthermore benefit from being set in Italic and Mediterranean contexts. This concluding chapter briefly recapitulates the arguments made in the main body of the book and the significance of each of those arguments for studies of ancient architecture and society. It also assesses how these findings relate to broader debates about Archaic Italy. Finally, it acknowledges the limitations of this analysis and highlights opportunities for future research. Part I of this book demonstrated that ancient religious architecture was a protean phenomenon. Three chapters analysed the ambiguous evidence for Iron Age sacred huts, the range of different buildings types associated with ritual activities in the seventh century BC, and the emergence of a separate architectural language for religious buildings during the Archaic period. Detailed analyses of foundations and roofs revealed that as changes in technology and society led to the widespread use of more permanent building materials, the physical fabric of central Italic settlements was also increasingly marked by the use of particular architectural forms and decorations to differentiate cult buildings from other structures, setting them apart in a form of architectural consecration.

Slope Stability Integrate Analyses: The Study Case of Mount Falcone (Central Italy)

2015 ◽  
pp. 1371-1376
Author(s):  
Domenico Aringoli ◽  
Marco Materazzi ◽  
Bernardino Gentili ◽  
Gilberto Pambianchi ◽  
Nicola Sciarra
Keyword(s):  
Slope Stability ◽  
Central Italy ◽  
Study Case

scholarly journals Recreational angling as a vector of freshwater invasions in Central Italy: perceptions and prevalence of illegal fish restocking

2018 ◽  
pp. 38 ◽  
Author(s):  
Jacopo Cerri ◽  
Alessandro Ciappelli ◽  
Andrea Lenuzza ◽  
Marco Zaccaroni ◽  
Annamaria Nocita
Keyword(s):  
Logistic Regression ◽  
Invasive Alien Species ◽  
Central Italy ◽  
Freshwater Ecosystems ◽  
Future Research ◽  
Structural Determinants ◽  
Travel Costs ◽  
Recreational Angling ◽  
Freshwater Invasions ◽  
Research Gap

Italian freshwater ecosystems were strongly affected by biological invasions during the last few decades. Recreational angling contributed to this, through the widespread use of invasive alien species for fish restocking. To date, no research is available about the psychological and structural determinants of deliberate fish restocking in Italy. This work aims to fill this research gap, through structured questionnaires administered to a sample of recreational anglers (n = 276) in the Arno river basin (Central Italy). A predictive model for fish restocking, based on a quasi-binomial logistic regression, was fit and multi-model inference was drawn, to highlight the most significant predictors. Respondents, who expected that most anglers practiced restocking and who believed restocking could create closer fishing spots, were more prone to illegally restock fish. Our findings indicate that expectations about illegal fish restocking might exist among specialized segments of anglers. Targeted communication campaigns must be enforced as soon as possible to change them. Furthermore, fish restocking is supposed to reduce the travel costs for angling: future research about this is needed to model invasion hotspots.

scholarly journals Time-dependent <i>Z-R</i> relationships for estimating rainfall fields from radar measurements

2010 ◽  
Vol 10 (1) ◽  
pp. 149-158 ◽  
Author(s):  
L. Alfieri ◽  
P. Claps ◽  
F. Laio
Keyword(s):  
Time Estimation ◽  
Rain Gauge ◽  
Rainfall Rate ◽  
Time Step ◽  
Radar Rainfall ◽  
Rain Gauges ◽  
Weather Radars ◽  
The North ◽  
Real Time Estimation ◽  
Power Law Equation

Abstract. The operational use of weather radars has become a widespread and useful tool for estimating rainfall fields. The radar-gauge adjustment is a commonly adopted technique which allows one to reduce bias and dispersion between radar rainfall estimates and the corresponding ground measurements provided by rain gauges. This paper investigates a new methodology for estimating radar-based rainfall fields by recalibrating at each time step the reflectivity-rainfall rate (Z-R) relationship on the basis of ground measurements provided by a rain gauge network. The power-law equation for converting reflectivity measurements into rainfall rates is readjusted at each time step, by calibrating its parameters using hourly Z-R pairs collected in the proximity of the considered time step. Calibration windows with duration between 1 and 24 h are used for estimating the parameters of the Z-R relationship. A case study pertaining to 19 rainfall events occurred in the north-western Italy is considered, in an area located within 25 km from the radar site, with available measurements of rainfall rate at the ground and radar reflectivity aloft. Results obtained with the proposed method are compared to those of three other literature methods. Applications are described for a posteriori evaluation of rainfall fields and for real-time estimation. Results suggest that the use of a calibration window of 2–5 h yields the best performances, with improvements that reach the 28% of the standard error obtained by using the most accurate fixed (climatological) Z-R relationship.

scholarly journals A Case-Study of Sustainable Countermeasures against Shallow Landslides in Central Italy

Geosciences ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 130
Author(s):  
Diana Salciarini ◽  
Evelina Volpe ◽  
Ludovica Di Pietro ◽  
Elisabetta Cattoni
Keyword(s):  
Slope Stability ◽  
Natural Environment ◽  
Mechanical Characteristics ◽  
Soil Property ◽  
Central Italy ◽  
Probabilistic Approach ◽  
Slope Stabilization ◽  
Standard Type ◽  
Technical Solutions

Traditional technical solutions for slope stabilization are generally costly and very impacting on the natural environment and landscape. A possible alternative for improving slope stability is based on the use of naturalistic engineering techniques, characterized by a low impact on the natural environment and being able to preserve the landscape identity and peculiarities. In this work, we present an application of such techniques for slope stabilization along a greenway located in central Italy, characterized by an extraordinary natural environment. First, 22 potentially unstable slopes have been identified and examined; then, among these, two standard type slopes have been selected. For both of them, an appropriate naturalistic engineering work has been proposed and stability analyses have been carried out. These have been performed by considering different piezometric conditions and using two different approaches: (a) a classical deterministic approach, which adopts deterministic values for the mechanical properties of the soils neglecting any uncertainty, and (b) a probabilistic approach that takes into account a statistical variability of the soil property values by means of their probability density functions (PDFs). The geometry of each slope derives from a digital model of the soil with 1 meter resolution, obtained through Light Detection and Ranging (LiDAR) survey provided by the Italian Ministry of the Environment. The soil mechanical characteristics and their PDFs are derived from the geotechnical soil property database of the Perugia Province. Results show an increase in slope stability produced by the adopted countermeasures measured in terms of Factor of Safety ( F s ), Probability of Failure (PoF) and efficiency.

Field measurements of water storage capacity in a loess–gravel capillary barrier cover using rainfall simulation tests

2017 ◽  
Vol 54 (11) ◽  
pp. 1523-1536 ◽  
Author(s):  
Liang-tong Zhan ◽  
Guang-yao Li ◽  
Wei-guo Jiao ◽  
Tao Wu ◽  
Ji-wu Lan ◽  
...  
Keyword(s):  
Storage Capacity ◽  
Water Storage ◽  
Field Measurements ◽  
Test Site ◽  
Water Entry ◽  
Rainfall Event ◽  
Capillary Barrier ◽  
Water Storage Capacity ◽  
Artificial Rainfall ◽  
Compacted Loess

A 30 m long × 20 m wide capillary barrier cover (CBC) test site was constructed at the Jiangcungou landfill in Xi’an, China. The cover consisted of a compacted loess layer with a thickness of 0.9 m underlain by a gravel layer. After the cover surface was kept bare and exposed to natural climate conditions for nearly 5 months, one artificial rainfall event was implemented at the site. Vegetation was established at the test site after the first rainfall event. Four months later, a second artificial rainfall event was applied to the surface of the vegetated site. The pore-water pressures (PWPs) and volumetric water contents (VWCs) of the cover were monitored using jet-filled tensiometers and time-domain reflectometry moisture probes, respectively. Surface runoff and percolation were measured using field collection devices. The field measurements demonstrated a more rapid response of PWPs to the rainfall compared to the response of the VWCs. Percolation was observed when the PWPs near the interface reached the water-entry value of the gravel at local points. At that moment, the measured VWC near the interface was less than the VWC according to the water-entry value. The observation indicated that preferential flows took place in the compacted loess during the rainfall. As a result, the maximum water storage capacity was not reached at the onset of percolation. When percolation ceased, the average PWP near the interface decreased below the water-entry value, while the VWC near the interface was higher than that at the onset of percolation. Water storage at the completion of percolation was approximately 5% greater than that at the onset of percolation. Compared with the monolithic loess cover, the loess–gravel CBC increased the available water storage capacity by 41% at the completion of percolation. Vegetation had an insignificant influence on water storage capacity.

Sign in / Sign up

Export Citation Format

Share Document