bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of geosynthetic stiffness on reinforced soil walls
Authors: Bathurst R.J.  , Nernheim A.  , Allen T.M.
Published: February 2025

The paper describes a series of four full-scale modular block walls that were constructed with reinforcement layers having different stiffness. The walls were 3.6 m in height and were reinforced with two different polypropylene geogrid reinforcement materials, a polyester geogrid and a welded wire mesh. Each was constructed with the same modular block facing and reinforcement spacing of 0.6 m. Maximum reinforcement loads are compared to values predicted using the current AASHTO Simplified Method and the K-stiffness Method. The predicted magnitude and distribution of reinforcement loads are shown to be more accurate using the K-stiffness Method.
Reproduction of structure due to aging of marine clay by addition of small amount of cement
Authors: Tsuchida T.  , Hirahara T.  , Takenobu M.
Published: February 2025

A new method to reproduce the agng effect of clay due to cementation in laboratory is presented. A small amount of portland cement was mixed with the slurries of three marine clays under controlling temperature. It was observed that the quasi-overconsolidation characteristics of natural marine clays of 5,000-100,000 years old were reproduced in laboratory by consolidating and curing them for 2 weeks.
Administrative Report: TC 40 – Forensic Geotechnical Engineering
Authors: Rao V. V. S.  , Babu G. L. Sivakumar
Published: February 2025

Forensic geotechnical engineering involves scientific and legalistic investigations and deductions to detect the causes as well as the process of distress in a structure, which are attributed to geotechnical origin. Cases of remedied installations where the analysis and evaluation of adopted remedial measures with regard to their effectiveness and economy may be subjected to judicial scrutiny also fall under this purview. The normally adopted standard procedures of testing, analysis, design and construction are not adequate for the forensic analysis in majority of cases. The test parameters and design assumptions will have to be representative of the actual conditions encountered at site. The forensic geotechnical engineer (who is different than the expert witness) should be able to justify the selection of these parameters in a court of law. Hence he has to be not only thorough in his field of specialization, but should also be familiar with legal procedures.
A new methodology of determination of soil compressibility
Authors: Stanciu A.  , Lungu I.
Published: February 2025

The settlement estimation of a shallow foundation requires the laboratory determination of the soil modulus or the compression index by oedometer or triaxial tests. The oedometer soil samples, by whose testing the two indices are determined, present a certain disturbance during their extraction from the ground and sampler tube respectively. This fact, together with setting the samples to a stress/strain state different from the in situ ones, determines a deviation of the results from reality. The authors designed a new oedometer device, to decrease or eliminate the induced testing errors, that differs from the classical one by the followings: the test is performed directly on the soil specimen removed from the boreholes without sampling the 70 mm diameter and 20 mm height cylinders; the stress-strain and stress-voids ratio curves, to determine these two indices, are obtained on samples with a partial lateral confined strain, under a stress state close to the one in situ; the new oedometer device provides the condition to perform a plate load test and obtain the stress-settlement curve, based on which the vertical subgrade modulus and by correlation the soil modulus can be derived. Thus, the paper presents the general approach to perform these two types of tests and their corresponding individual stages to quantitatively assess the soil compressibility by the soil modulus and compression index, established for pre-existing and induced stress states as similar as possible to the in situ ones, before and after construction is performed.
Soft soils improvement solution. Design based on the laboratory test results on scale model
Authors: Chirică A.  , Olteanu A.  , Serbulea M.S.  , Boţi I.
Published: February 2025

The paper refers to a national road sector approximately 5km long that was built on a swamp area. The general slope of the adjacent ground surface lead to the formation of a small concave area where the rainwater gathers and floods both the 1.5-2.0m tall embankment base and subgrade. Thus, due to the field geomorphology, which had not been properly taken into account within the frame of the geotechnical report, during the rainy seasons of the year, autumn especially, the level of the underground water table may rise to a depth of 1.60÷2.00m, very close to the natural ground level. In order to choose and dimension the measures for increasing the subgrade bearing capacity, in the laboratory were performed tests on samples prepared from reduced scale model. From the very beginning risen the solution of micro piles made of a lime, cement and sand mixture. The micro piles fulfilled a double purpose: on one hand they accelerated the primary consolidation process and on the other hand they lead to the improvement of the structured clay physical and mechanical properties. In the paper are presented the laboratory test results both on natural soil and treated one. The parameters obtained from laboratory were used in the model of foundation ground vertical and radial consolidation.
Effect of particle shape and angularity on dilation of granular soils: a discrete element approach
Authors: Sallam A.M.  , Ashmawy A.K.
Published: February 2025

The Discrete Element Method (DEM) was first introduced by Cundall and Strack (1979) to model granular soil particles as discs in 2D and spheres in 3D. Ashmawy et al (2003) developed the Overlapping Rigid Clusters (ORC) method to capture particles actual shape. This paper presents the results of a study performed to explore the effect of particle shape and angularity on strength and dilatancy properties of granular soils using DEM utilizing the ORC method. Triaxial tests under pure shear conditions were modeled for different particle shape and angularity groups under different initial conditions. The developed stress-strain relationships were used to explore the dependency of maximum volumetric strain, maximum dilation angle, and the resulted residual shear strength angle on shape and angularity factors was explored. The numerical study concluded that the critical state lines, for different shape and angularity groups, were shifted upward (more dilation) compared to circular particles. The critical state lines showed significant dependency on interparticle frictions. It was concluded that there is no one-to-one equivalency between interparticle friction and shape or angularity. Instead, the interparticle friction must be continuously altered as function of confining pressure and void ratio to achieve the required effect.
Behaviour of transdanubian clay under unloading and reloading
Authors: Koch E.
Published: February 2025

In recent years, in the field of geotechnical design, software based on FEM has come to the front. Advanced computer programs make it possible to use more developed soil models besides the most current elastic-plastic Mohr-Coulomb model. By using these computer programs, nonlinear behaviour of the soil can be followed better, even in the case of more complicated load events. Among the constitutive models incorporated in the commercial software the Hardening Soil Model (HS) and Soft Soil Model (SS) are the most promising ones. Observations and experience gained in tunnel construction, deep open excavation or preloaded embankment prove that with these soil models reality can be followed more accurately, especially in cases where unloading and reloading are present.
Experimental determination of statistical representative volume element in plane strain compression of dense sand
Authors: Jang E.R.  , Chung C.K.  , Kim M.M.  , Jung Y.-H.
Published: February 2025

To appropriately account for wide variance of soil responses in computing averaged properties of granular soils, the representative volume element (RVE) of the soil specimen in plane strain experiment was investigated. A compression test on Jumunjin sand was conducted via the plain strain testing device with a transparent wall to capture the digital images without distortion. The displacement of a particular material point centered at a particle subset was measured via digital image analysis using two consecutive captured images. To evaluate engineering strains from the heterogeneous displacement field, we employed the linear regression of the displacement in the selected subset of an image. Various sizes of the RVE of the soil specimen were tested in terms of the statistics of the deformation modulus. Deformation modulus in a selected size of the particle subset was evaluated from the strain field obtained from the digital image analysis. By analyzing the statistics of the deformation moduli distribution for various sizes of the RVE, we discussed the proper size of the RVE of the soil specimen subject to the plane strain compression.
Experimental study of the pullout resistance of ribbed anchors in sands
Authors: Irsyam M.  , Hasan L.  , Hryciwq R.D.
Published: February 2025

An experimental study into the pullout resistance of cylindrical anchor in sands was carried out in a triaxial testing tank that applied horizontal and vertical confining pressures. The experiment was carried out on both dense and loose sand conditions at various confining pressures. Several types of anchors were investigated, they included smooth, rough, and ribbed anchors with different rib spacings. In dense sand, degradation that results in increasing void ratio occurs at the interface, therefore anchor resistance decreases in subsequent cycles. In loose sand, the degradation tends to decrease the void ratio at the interface. As a result, anchor resistance in subsequent cycles is either relatively constant or increases. The contribution of passive resistance on the ribs and friction at the interface results in a coefficient of apparent friction (μ*) for both the peak and the residual conditions. The value of μ*is influenced by compressive normal stress, soil density and rib spacing, whereas the coefficient of lateral earth pressure at rest (Ko) has little influence on the anchor resistance.
Numerical modelling of creep in soft soils
Authors: Leoni Martino  , Vermeer Pieter A.
Published: February 2025

A new constitutive model for time-dependent behaviour of soft soils has been recently proposed. Stemming from a previously developed viscoelastic isotropic model based on ellipses of Modified Cam Clay, anisotropy was taken into account by introducing a fabric tensor to represent the rotation of the constitutive ellipses in p'-q (mean effective stress-deviatoric stress) plane. Due to the particle orientation induced by deposition mechanism, natural soils are anisotropic in terms of strength and stiffness. The improvement induced by the new formulation is particularly evident in stress paths in extension. The new soil constants required by the anisotropic formulation need no calibration, since they can be expressed in terms of parameters already used in the isotropic model and familiar to practicing geotechnical engineers. In this paper, the numerical analysis of an embankment on soft soils has been carried out, in order to investigate on the differences in terms of predictions of vertical and horizontal displacements between the isotropic and the anisotropic creep model.
Numerical Implementation of a Viscoplastic Constitutive Equation for the Modelling of Tailings Heaps
Authors: Katzenbach R.  , Leppla S.  , Wachter S.
Published: February 2025

For the modelling and simulation of the time dependent material behavior of rock salt a viscoplastic constitutive equation was developed and implemented into a Finite-Element system at the Institute and the Laboratory of Geotechnics of Technische Universität Darmstadt. The time dependent, three-dimensional constitutive equation is applied for the geotechnical modelling of tailings heaps with heights up to 200 m consisting of deposited rock salt. The deposited rock salt is a waste product of the potassic fertilizer production. The paper shows the theoretical basis, the structure, the implementation and the application of the implemented constitutive equation with the name CAPCREEP.
Study on generalized scaling law in centrifuge modeling with flat layered media
Authors: Tobita T.  , Iai S.  , Noda S.
Published: February 2025

Applicability of the two stage scaling relationship called generalized scaling law for centrifuge tests proposed by Iai et al. (2005) is investigated for dynamic response of flat layered media. In this scaling law, recorded physical model parameters are, firstly, converted to those in the virtual 1G field with scaling factor for centrifuge model tests, η. Then the parameters are further converted to prototype with scaling factor for 1G tests, μ (Iai, 1989). By using this scaling law, model tests with scaling factor (prototype/physical model) of 100 or much higher may be possible without encountering problems, e.g., scaling of granular material. The generalized scaling law in centrifuge modeling is investigated through dynamic response of compacted sand. In the experiments, a prototype is scaled down to 1/100 with 9 combinations of scaling factors of virtual 1 G and centrifugal field. Input motions are also scaled accordingly. Then the generalized scaling relation is applied to examine responses in the prototype scale. Responses compared in the present study are shear wave velocity, displacement, and acceleration. If the generalized scaling law is valid, these responses in the prototype scale are identical regardless of scaling factors. Results confirm the validity of the scaling relation of these physical parameters in a range of 40 G to 70 G of centrifugal accelerations.
Compacted soil shear strength characterization on inclined plane test
Authors: Pitanga H.N.  , Vilar O.M.  , Gourc J.P.
Published: February 2025

Many landfill cover system slidings have occurred and small shear strength in the interface between cover components has been evoked as the main reason of the observed failures. However, the poor compaction characteristics and low associated strength of some cover soils suggest that in some instances their can influence the cover sliding instead of interface between components. In this paper, the inclined plane test is used to determine geosynthetics interfaces and compacted soil shear strength in cases where the initial normal stress is small. It will be shown that the poorly compacted cover soil can determine the potential failure surface under some conditions and that an appropriate compaction can increase the angle of shearing resistence and to ensure the soil stability in the cover system.
Improvement of engineering characteristics of expansive clays by sand mixing
Authors: Farooq Khalid  , Virk Khadim A.
Published: February 2025

Expansive Soils are a worldwide problem that poses several challenges for civil engineers. They are considered potential natural hazard, which can cause extensive damage to structures if not adequately treated. The expansive soils have caused severe distresses to various civil engineering structures, especially to lightly loaded structures such as houses, floors, highway pavements, canal linings etc. One of the mitigation techniques of such soils is to mix them with soils which are not swelling in nature. In this paper, the results of three series of tests are presented in which a swelling clay has been mixed with sand in varying amount ranging from zero to 35%. Through these tests, the effects of sand mixing on deformation and strength characteristics of swelling clay have been investigated. For performing such tests, the swelling clay samples have been procured from an expansive soil area in Pakistan. The clay-sand samples were remolded at Modified AASHTO density and optimum moisture content with proportion of sand ranging between 0-35 percent. Three series of tests performed included, Modified AASHTO compaction, California Bearing Ratio, One-dimensional consolidation tests in addition to basic property tests. The results of the study showed that mixing of sand in swelling clay remarkably reduces swelling potential of expansive clay and improves its strength characteristics. The sample with out mixing sand content showed a swell potential of the order of 3.5 % and this reduced to about 0.5% when the clay was mixed with 35% of sand. The swell pressure for sample without mixing sand was found to be 90 kPa and reduced to about 10 kPa for sample mixed with 35% sand. The CBR values increased from a value of 4% in case of pure clay sample to a value of 8% when the clay was mixed with 30-35% sand. The Modified AASHTO density was increased from 18.2 kN/m3to 19.4 kN/m3in case of pure clay and clay mixed with 30-35% sand, respectively. These results are very promising and have application when such clays are being used as highway subgarde soil, where there is requirement of mitigating their expansive nature along with improving their strength characteristics like CBR etc.
Comparing Vibratory and Impact Laboratory Compaction Methods
Authors: Lange D.P.  , Fanourakis G.
Published: February 2025

Laboratory analysis carried out on different soils shows that vibratory and impact compaction produce different results. Standard methods based on BS 1377: 1975 using the vibratory hammer and mod AASHTO for impact were applied. Results obtained for maximum dry density and optimum moisture content were compared for each soil. It was found that the vibratory method was more suitable than impact for non-cohesive soils and gravels. Cohesive soils reached maximum compaction at higher moisture contents using vibration as opposed to impact, but at lower densities. It is clear that field densities under vibratory compaction would be difficult to achieve where the laboratory control method was based on impact.
An approach to evaluate internal friction angle from dynamic penetration tests
Authors: Lobo B.O.  , Schnaid F.  , Rocha M.M.  , Odebrecht E.
Published: February 2025

This paper presents an approach to predict the internal friction angle of cohesionless soils from dynamic penetration tests. The proposed methodology allies the dimensional equation technique (TT numbers) with a numerical simulation routine that is able to reproduce the dynamic test response for a SPT or for any other dynamically driven device such as LPT (Lobo, 2007). The numerical routine models the dynamic reaction mechanism, predicting the SPT penetration or blow count N. Based on typical resistance and rigidity values of cohesionless soils, an analytical solution is proposed to assess the effective friction angle. The results have proven it possible to model the penetration mechanism and, as a consequence, to use a dynamic test as an inverse boundary value problem to assess soil properties in granular materials.
Stress history and preconsolidation pressure evaluation from SCPTU
Authors: Massad F.
Published: February 2025

The paper deals with the evaluation of the preconsolidation pressure (σ′p) of marine clays of Santos, Brazil, from Static Cone Penetration Tests (SCPTUs), in the light of their geological history. It starts with a brief account of the origin, the evolution and the geotechnical properties of the marine sediments. Many SCPTUs have been carried out in the Holocene Clays (SFL Clays), preconsolidated chiefly by negative sea-level oscillations or dune action. The estimation of σ′pwas done by means of the Kulhaway and Mayne's equation, that uses the net tip resistance and an empirical factor (Nσt) that depends on soil type and also on the kind of sampler used to extract undisturbed samples. In this paper its value was determined using a criteria that takes into account the stress history: the correlations with odometer test results were considered in a geological and geotechnical context. It is shown that Nσtranged from 3.0 to 3.9 for the SFL Clays. A confirmation of these figures is presented in two ways: indirectly, using field tests, and directly, by comparing the computed σ′p
Development and field application of static cone penetrometer combined with dynamic penetration
Authors: Rito F.  , Sugawara N.
Published: February 2025

New type static cone penetration equipment called combination cone was developed for more appropriate evaluation of housing land bearing capacity. The combination cone penetration equipment installs dynamic penetration mechanism to increase cone penetration power, but does not attach the pore water pressure measurement function to promote the efficiency of the work. To establish the bearing capacity evaluation method with high reliability from the combination cone penetration test result, the in-situ experiment of combination cone penetration test, plate loading test, three-component cone penetration test and Swedish weight sounding test was executed on a lot of sites in Kanto and Kansai district in Japan. An empirical formula of the bearing capacity was proposed based on this correlation. On the other hand, a good correlation was not obtained between number of half turn Nswof Swedish weight sounding test result and cone resistance qc. Some problems when the bearing capacity was calculated from Swedish weight sounding test result were confirmed. To be obtained higher additional values, the surface wave exploration can be combined with the combination cone penetration test. The surface wave exploration can be obtained the cross section of S-wave velocity corresponding to soil stiffness. The surface wave exploration combined with the combination cone penetration test is very useful in-situ investigation approach for the estimation of the bearing capacity of housing land.
Conceptual method for estimation of dike breach sensitivity, including geotechnical and geophysical testing
Authors: Van Alboom G.  , Vincke L.  , Peeters P.  , Depreter F.
Published: February 2025

In order to estimate breach sensitivity of Flemish river dikes a conceptual method was developed. For each failure mechanism representative parameters are weighed and the outcome is a failure index for the considered failure mechanism. On basis of these failure indexes critical dike sections can be detected, which can be investigated in detail, including extensive geotechnical in situ and laboratory testing. Geophysical methods apt to give a first raw insight in possible weaker dike sections were investigated on their merits and results. For 2 typical dike sections geophysical methods were performed and compared with the results of standard geotechnical testing (CPT, borings).
The Wide Band Sparse Element Array Antennas – WiSE project: an overview
Authors: Lager Ioan E.  , Ligthart Leo P.  , van Genderen Piet
Published: February 2025

A review on the Wide Band Sparse Element Array Antennas (WiSE) project is provided. After describing the general structure of the project and its initial goals, the activities undertaken in the two principal, and the various spin-off and supporting lines of research will be outlined. The most prominent theoretical and applicative achievements will be enumerated, by insisting on the delivered concept demonstrators and scientific output and, at the same time, on the societal impact of the obtained results.
Effects of ferric oxyhydroxide coatings on sand shear response: a laboratory approach to chemical weathering
Authors: Larrahondo J.M.  , Zhao Q.  , Burns S.E.  , Elliott W.C.
Published: February 2025

Geomaterials can exhibit dramatic changes in mechanical behavior upon chemical and physical weathering. Specifically, chemical weathering of iron Fe(II) minerals yields products, including iron Fe(III) oxides, hydroxides and oxyhydroxides, which precipitate as coatings on rock and soil surfaces due to their low aqueous solubility. The general objective of this research is to readily isolate, for controlled study in the laboratory, the effect of such chemical weathering on the stress-strain relationships and strength of coarse-grained soils. Particles of fine silica sand were coated by chemical adsorption of the iron Fe(III) oxyhydroxide akaganéite onto the sand surface under controlled pH and ionic strength conditions, and at standard pressure and room temperature. Akaganéite is a chemical weathering product formed by precipitation after oxidation of iron Fe(II) minerals, and is a precursor of the chemical weathering products goethite and hematite. To identify the effect of the oxyhydroxide coating on soil behavior, both the coated sand and uncoated control samples were tested in direct shear. Chemical-weathering effects were thus evaluated independently from stress history, parent rock discontinuities, and biological influence. The results presented herein show that the oxyhydroxide coating increased the residual strength, dilatancy and friction angle of the sand, with no strain delay exhibited in the peak shear strength.
Applications of Remote Sensing in Archaeology: Surface and sub-surface feature detection over UNESCO World Heritage sites and archaeological sites in Italy using optical and radar data
Authors: Dore Nicole  , Patruno Jolanda  , Sarti Francesco  , Ruescas Ana B.  , Hernandez M.
Published: February 2025

The purpose of the research is to understand the potential of polarimetric and SAR response of different archaeological structures on the surface and subsurface over different landscapes and to define and propose a methodology for the integration of information extracted from polarimetric radar as a new, additional tool for archaeological applications. Test sites selected for this work are Vulci, Arpi (Italy), Gebel Barkal (Sudan) and Calakmul (Mexico). Interesting preliminary results of relevance for this humanistic science are shown, based on the joint use of polarimetric SAR and optical data.
Land-Cover Classification and Unmixing of Hyperion Image in Area of Anopoli
Authors: Elatawneh A.  , Manakos I.  , Kalaitzidis C.  , Schneider T.
Published: February 2025

The Hyperion sensor is unique because it is the only high spectral resolution hyperspectral sensor on a satellite platform. The hyperspectral capability of the sensor could potentially allow for classifications of increased accuracy, in comparison to those produced from multispectral data. This study evaluates the capability of Hyperion data for discriminating land-cover classes in the Anopoli region (southwest Crete, Greece), through different classification techniques and spectral unmixing procedure. Preprocessing of Hyperion data is essential before any analysis takes place, and it includes interpolation of the wavelengths to a common set, noise reduction by using the minimum noise fraction (MNF), and other commonly applied corrections. Land-cover classifications were performed on the Hyperion satellite data through the Spectral Angle Mapper (SAM) pixel-based technique, as well as the object-based technique. In order to take advantage of the hyperspectral data of Hyperion, and overcome the problem of low spatial resolution, non-linear spectral unmixing approaches were employed, by using artificial neural network (ANN). The spectral end-members used in those approaches were constructed from QuickBird data. All the results were evaluated using the ground truth data derived from high spatial resolution imagery (QuickBird) and field data. All classification results mainly appeared to suffer from the relatively low spatial resolution of the Hyperion sensor and the spectral similarity among many land cover classes. The results show that the object-based classification outperformed the pixel-based classification and achieved the highest overall accuracy. The pixel-based classification and ANN results were highly dependent on the extent that the end-members were representative of the class. However, the pixel-based technique was very successful in differentiating land cover classes with dense vegetation cover.
Chemicomorphological Characterization of Etna's Plume by Atmospheric Lidar, Satellite Radiometers and In-situ Measurements
Authors: Fiorani Luca  , Aiuppa Alessandro  , Buongiorno Maria Fabrizia  , Colao Francesco  , Del Bugaro Dino  , Fantoni Roberta  , Giudice Gaetano  , Giuffrida Giovanni  , Guerrieri Lorenzo  , Guida Roberto  , Kataev Mikhail Yu.  , Kataev Sergey G.  , Liuzzo Marco  , Lonchin Alexey V.  , Palucci Antonio  , Spinetti Claudia  , Sykhanov Alexander Ya.
Published: February 2025

The Etna's plume has been measured by in-situ gas analyzers at the main crater, atmospheric lidar deployed on the volcano East flank and satellite radiometers. Thanks to the integration of those different techniques, a 3D reconstruction of the plume has been achieved. This approach could lead to a deeper understanding of the chemicophysical phenomena taking place inside the plume.
Effect of Spatial Resolution on Intertidal Sediment Characterization
Authors: Ibrahim E.  , Govaerts A.  , Regmi P.  , Druyts J.  , van der Wal D.  , Adam S.  , Vervoort A.  , Monbaliu J.  , De Wever A.  , Sabbe K.  , Forster R.
Published: February 2025

Remote sensing offers opportunities to efficiently acquire data of intertidal flats and characterize intertidal sediments. Each type of imagery with a different spatial resolution offers a distinctive perception. The objective of this research is to investigate the impact of these properties on sediment characterization. A hyperspectral airborne image of 4 m pixel size accompanied by field data is used. The study consists of a geostatistical analysis of spatial correlations for the hyperspectral image and imagery depicting specific sediment properties (moisture content and chlorophyll a content). The results show that there is information lost when the pixel size of the image increases to 24 m pixel size. To characterize relative moisture content, a maximum pixel size of 12 m can be used. While for chlorophyll a content characterization, increasing the pixel size (investigated up to 72 m) does not degrade the information significantly. The research presented in this paper is funded by the Belgian Science Policy Office in the frame of the STEREO II programme (ALGASED project).
Integration of Remote Sensing and GIS for Archaeological Investigations
Authors: Maktav D.  , Crow J.  , Kolay C.  , Yegen B.  , Onoz B.  , Sunar F.  , Coskun G.  , Karadogan H.  , Cakan M.  , Akar I.  , Uysal C.  , Gucluer D.  , Geze B.  , Ince G.
Published: February 2025

The western hinterland of the modern city of Istanbul contains some of the most remarkable monuments of ancient and medieval hydraulic engineering dating from the fourth to the twelfth centuries AD, including lines of aqueduct channels and bridges extending up to 336 km to the west of the modern city. Until recently fieldwork has been limited and only within the last two decades have there been serious attempts to map the complexity of the monuments and water lines. The dense forest which covers much of the northern hills of Thrace is a major factor restricting fieldwork and survey, yet at the same time the woodland ensures the preservation of much of the system. Two previous studies of the water supply system have been able to identify the major spring sources, to map the line of the water supply channels and to record and locate over sixty bridges which are a key component of the system. However these studies have been constrained as they are not able to integrate adequately this survey data. The new research programme between Istanbul Technical University (ITU) and Edinburgh University commenced in 2007 and includes all existing GPS data and archaeological observations to be incorporated as part of a modern GIS combining the topographical and hydraulic information available from 1:25 000 digital maps with a wide range of high and medium resolution remotely sensed data. Further surface GPS based archaeological survey has been undertaken over the past two years and has been able document a significant number of the extant channels and bridges. Using high resolution IKONOS images and orthophotos it has been possible to create a textured land surface of forests and fields for the Thracian digital surface model (DSM) in which to situate the various monuments and channels of the water supply system. This digital resource is now capable of providing the basis for future archaeological documentation and analysis and two case studies are given. Integrated with multi-spectral data this gives the opportunity to view the system in its wider setting and also to identify major urban and landscape changes impacting on the long-term conservation and management of the ancient remains.
Data fusion: taking into account the modulation transfer function in ARSIS-based pansharpening methods
Authors: Massip Pierre  , Blanc Philippe  , Wald Lucien
Published: February 2025

Multispectral images provided by satellite have a poor spatial resolution while panchromatic images (PAN) exhibit a spatial resolution two or four times better. Data fusion is a mean to synthesize MS images at higher spatial resolution than original by exploiting the high spatial resolution of the PAN. This process is often called pan-sharpening. The synthesized multispectral images should be as close as possible to those that would have been acquired by the corresponding sensors if they had this high resolution. The methods based on the concept “Amélioration de la Résolution Spatiale par Injection de Structures” (ARSIS) concept are able to deliver synthesized images with good spectral quality but whose geometrical quality can still be enhanced. We propose to consider the characteristics of the sensor to improve the geometrical quality. We take explicitly into account the modulation transfer function (MTF) of the sensor in the fusion process. Though this study is limited in methods and data, we observe a better restitution of the geometry and an improvement in the majority of quality indices classically used in pan-sharpening. The communication also presents a means to assess the respect of the synthesis property from a MTF point of view.
Modelling track geometry by a bivariate Gamma wear process, with application to maintenance
Authors: Mercier Sophie  , Meier-Hirmer Carolina  , Roussignol Michel
Published: February 2025

This paper discusses the maintenance optimization of a railway track, based on the observation of two dependent randomly increasing deterioration indicators. These two indicators are modelled through a bivariate Gamma process constructed by trivariate reduction. Empirical and maximum likelihood estimators are given for the process parameters and tested on simulated data. The EM algorithm is used to compute the maximum likelihood estimators. A bivariate Gamma process is then fitted to real data of railway track deterioration. Preventive maintenance scheduling is studied, ensuring that the railway track keeps a good quality with a high probability. The results are compared to those based on both indicators taken separately, and also on one single indicator (usually taken for current track maintenance). The results based on the joined information are proved to be safer than the other ones, which shows the interest of the bivariate model.
Multi-criteria optimization of life-cycle performance of structural systems under uncertainty
Authors: Frangopol Dan M.  , Okasha Nader M.
Published: February 2025

Prediction of the life-cycle performance of structural systems must be accompanied with an efficient intervention planning procedure that assures the safe upkeep of structures. Multi-criteria optimization is an effective approach for conducting this procedure. Life-cycle performance of structural systems is typically quantified by means of performance indicators. The ability of the performance measures and their predictive models to accurately interpret and quantify the effects of applying maintenance interventions is necessary. The objective of this paper is to review recent advances in methods of multi-criteria optimization of life-cycle performance of structural systems under uncertainty. Two approaches for finding optimum maintenance strategies for deteriorating structural systems through multi-criteria optimization and using genetic algorithms are presented with applications. These approaches use different problem formulations and types of performance indicators.
Vulnerabilities and Protection of Satellite Networks interconnected with terrestrial segments
Authors: Belli F.  , Luglio M.  , Roseti C.
Published: February 2025

Integration of different networks enhances sustainable applications but specific vulnerabilities must be faced up too. New network components often are introduced to efficiently adapt different technologies, whereas in some cases they can be exploited as sources for generation of anomalous events in the interconnected networks attributable to security attacks. This paper deals with security for heterogeneous and inter-operable communication networks including a satellite segment, focusing on the application of an Intrusion Detection System (IDS) on the target scenario. The baseline envisages the presence of Performance Enhancing Proxies (PEPs) at the edges of satellite links, which implies the twofold effect of improving TCP performance but also increasing a PEP-related vulnerability due to the violation of the end-to-end semantic of TCP. The paper addresses the above mentioned issue through the realization of a test bed including a real geostationary satellite link operated by Telespazio. Outcomes of experiments show the effectiveness of the application of the proposed IDS system.
The Economics of Utility Services in the Future Internet
Authors: Li Man-Sze
Published: February 2025

“Utility” is by no means new a new concept in ICT. At the time of writing, the European Union is putting forward the argument to extend “universal service” to broadband communication services. The universal service argument may in future be extended beyond broadband to other Internet services, or services running on top of the communications infrastructure of the Internet. This paper considers the economic underpinnings of utility services in the Future Internet context. It examines a number of relevant economic models and basic economic assumptions in an attempt to answer the question: are utility services economically viable? It identifies several key issues and spells out some implications for the Future Internet service models on the basis of that analysis. The paper concludes that market forces alone are unlikely to be sufficient for utility service provision in ICT; utility service markets have the intrinsic characteristics of a monopoly. We need new and bold economic models for the emerging and future Internet scenarios.
The Use of Process Simulation Methods in Support of Organisational Learning in Availability Contracting
Authors: McEwan W.  , Butterfield J.
Published: February 2025

Traditional business models in the aerospace industry are based on a conventional supplier to customer relationship based on the design, manufacture and consequent delivery of the physical product. Service provision, from the manufacturer's perspective, is typically limited to the supply of procedural documentation and the provision of spare parts to the end user as the product passes to the latter stages of its intended lifecycle. Challenging economic and political conditions have resulted in end users re-structuring their core business activities, particularly in the defence sector, to a recognised need for improved reliability and a reduction in maintenance requirements. This has resulted in the need for original equipment manufacturers (OEMs) to integrate and manage support service activities in order to deliver platform availability. The need for OEMs to evolve their design, manufacture and supply strategies by focusing on customer requirement has revealed a need for reconstruction of traditional internal behaviours and design methodologies. Application of organisational learning is now a well recognised technique for innovative companies to achieve long term growth and sustained technical development, and hence, greater market command. This technique focuses on the process by which the organisation's knowledge and value base changes, leading to improved problem solving ability and capacity for action. From the perspective of availability contracting, knowledge and the processes by which it is generated, used and retained, become primary assets within the learning organisation. This paper will introduce the application of digital methods as tools for asset management within the learning organisation. Experiences drawn from three separate bodies of work, carried out at this institution, are expounded here as proposed methodologies for the application of digital methods by which maintainability can be integrated as a key design requirement at the earliest stages of product development. Specific digital tool based methodologies for the integration of maintenance planning within product design are identified and demonstrated. It is also shown that the creation and capture of knowledge through the manipulation of digital assets delivers both the specific design drivers for MRO activities and a universal medium for knowledge dissemination and discussion within complex engineering design organisations.
Selecting Reference Set in Disaggregation Aggregation Multicriteria Decision Aid Approach Utilizing Clustering Techniques with Dissimilarity Thresholds
Authors: Spyridakos Athanasios
Published: February 2025

The selection of the reference set in the frame of Disaggregation – Aggregation (D-A) methods (UTA*, UTA II, UTADIS), constitutes one of the most important steps of the process, while it influences the accuracy and reliability of the assessed preference model. The reference set ought to satisfy two conditions: a) the alternatives of the reference set should be familiar to the Decision Maker (DM) so as to express his/her preferences from a known situation; and b) the selected alternatives have to be representative of the total set, so that all the different points of view of the decision space to be taken into consideration. This paper presents a clustering technique that is embedded in the Multicriteria Decision Aid Systems MINORA and MIIDAS, which incorporates threshold of dissimilarity in order to support DMs or Decision Analysts (DAs) to select a representative reference set. This technique is compared with the most familiar multivariate data analysis clustering methods, such as k-means and hierarchical. Also, the technique is illustrated through a real world case study.
Experimental and numerical Analyses of Aluminium Frames exposed to Fire Conditions
Authors: Maljaars J.  , Soetens F.
Published: February 2025

Design models are required to assess the behaviour in fire of aluminium structures. These models need to be validated by comparison with test. Up to now tests results are only available for (small scale) individual components. This paper provides the results of tests carried out on frames. A finite element model in combination with a sophisticated constitutive model are used to simulate the test. The results of the simulations agree with that of the tests at room and elevated temperatures.
Aluminium, Architecture and Human Ecology
Authors: Stacey Michael
Published: February 2025

This paper demonstrates the potential for aluminium to contribute to the creation of high quality contemporary architecture, throughout the globe. Architecture that is durable and beautiful, providing comfort and human well-being. It examines how the architectural profession can learn from its own experiences and benefit from technology transfer from other industries. The paper also explores the responsible sourcing of construction products and divergent views on recycled content. The case study architecture will be drawn from the author's own practice and key international exemplars, identifying the potential for aluminium to contribute to human ecology.
Characterization of AZ91/Al
Authors: Eghtedari B.  , Meratian M.  , Aryanpour G.  , Mohammadi M.
Published: February 2025

Nowadays, magnesium alloys are increasingly used in automotive and aerospace applications mainly due to their light weight combined with reasonable mechanical properties. However, magnesium (alloys) matrix composites are manufactured in order to improve some of the monotonic mechanical properties. In the present work, the AZ91 (Mg-Al-Zn) alloy was used as composite matrix reinforced with alumina preform through the infiltration route form interpenetrating phase composite. The obtained composite samples were characterized for the sake of comparison with monolithic properties. The dependence of composite properties was studied as a function of reinforcement volume fraction and applied pressure. Results revealed that the composites exhibited higher density and decreased porosity compared to the matrix base alloy. However, monotonic ultimate compression strength and ductility decreased. This was attributed to presence of thermal compressive stresses at reinforcement/matrix interface as well as occurrence of interfacial reaction products such as MgAl2O4 spinel phase.
Cross-sectional Classification of Aluminium Beams subjected to Fire
Authors: van der Meulen O.R.  , Maljaars J.  , Soetens F.
Published: February 2025

Fire design for aluminium alloy beams is performed using the same system of cross-sectional slenderness classes as is employed at room temperature. Identical width-over-thickness ratio limits are used to define the boundaries between the classes. These limits are known (and demonstrated) to be conservative, but may in fact be over-conservative. Especially for tempered alloys, the geometric limits may be relaxed considerably, allowing cross-sections to be upgraded in class for fire design calculations.
Analysis of hot Formability of Al-4.6Mg-0.6Mn Alloy (AA5083)
Authors: Fang Gang  , Liao Pei-Gen  , Zhou Jie  , Duszczyk Jurek
Published: February 2025

The hot formability of a work-hardenable aluminium alloy AA5083 was studied by means of uniaxial compression testing at temperatures of 300–500°C and strain rates of 0.001–10 s−1. The constants in the hyperbolic sine equation were compared with those in the literatures. Microstructure evolution during deformation and cooling was examined and the effects of temperature and strain rate on grain size were investigated. A high deformation temperature was found to favour static recrystallization, while a low strain rate facilitated dynamic recrystallization.
The Influence of small Voids on the Fatigue Strength of Friction Stir Welds in the Aluminium Alloy AA6061-T6
Authors: Kahl Sören
Published: February 2025

Flat rectangular profiles of the aluminium alloy AA6061-T6 were friction stir welded to butt joints. Welding parameters outside the process window generated a random mixture of good welds and welds with small voids. These voids reduced the tensile strength by 10%, the ductility by half, and the fatigue strength by 20%. Voids can easily be detected on fracture surfaces. Void-free specimens have 10% lower fatigue strength if the fatigue crack extends over a corner of the specimen cross section.
Automatic free-text-tagging of online news archives
Authors: Farkas Richárd  , Berend Gábor  , Hegedűs István  , Kárpáti András  , Krich Balázs
Published: February 2025

In this paper, we shall introduce the problem of free-text-tagging of online news archives. From an application point of view, it has many benefits for online news portals and on the other hand, the task has unique characteristics compared to existing approaches for free-text-tagging. We shall describe our system, which was developed for the archive (consisting of 370 thousand articles) of the most visited Hungarian news portal www.origo.hu, along with research questions encountered and solved during our task. As the evaluation of tagging is not straightforward at the end of the project the news company manually investigated the tagging of the automatic system which yielded an F-measure of 71.9.