bluuebunny/crossref_metadata_2025 huggingface dataset:
Three-dimensional numerical modelling of a high slope cut in a rock mass having complex geological formations
Authors: Méndez Bogart  , Botero Eduardo  , Romo Miguel P.  , Marengo Humberto
Published: February 2025

The paper describes the 3D numerical modelling studies of a 280 m height slope cut in a rock mass having complex geological formations. The modelling was carried out to evaluate both the static and dynamic stability of the projected rock slope, which will be located in northern Mexico. The construction site presents complex geological features like faults and dikes as well as several geological formations from varying qualities and fracture conditions. Available field data made it possible to incorporate the most important geological and topographical features with high degree of detail. The geomechanical model was developed into the commercial three-dimensional distinct element code 3DEC. This code was chosen because it has been widely used for rock mechanics problems and has been evaluated in a number of instances. Also, the code has a built-in programming language (FISH) that allows the user to expand the code's usefulness by using it as a numerical-analysis platform. Data available from field explorations allowed applying the Hoek-Brown and Bieniawski's criteria to estimate mechanical and elastic properties for the rock mass. These properties were consistent with in situ geophysical explorations. Before simulating the construction, an analysis was carried out for the pre-construction conditions under both static and dynamic loading as to validate the model's ability to represent the initially-stable site conditions. During the static analyses of the construction process, the full 3D model was used to simulate this process in four stages. A FISH function was implemented into the code to compute the factor of safety against material failure using the Mohr-Coulomb criteria in each excavation stage. The effect of blast damage and stress relaxation in the factor of safety was also investigated. After the construction simulation was done, a seismic motion was input at the model's base in the slope's normal direction. To substantially reduce the computing time due to the size and degree of detail of the model, dynamic analyses were performed on selected 3D portions (three-dimensional slices) of the model. However, these dynamic analyses simulated the true three-dimensional behavior by applying velocity conditions at the slices' outer boundaries, thus establishing continuity conditions at slices' lateral boundaries. This initial assessment of the rock-slope stability was carried out purposely to anticipate problems that may arise during the construction, and thus take decisions on the possible support measures.
Seismic response analysis of a river embankment on deep sedimentary strata
Authors: Vrettos C.
Published: February 2025

The seismic response analysis of a river embankment on very deep sedimentary strata in a region of medium seismicity is considered. A synthetic seismic input motion is determined from code response spectra with an extrapolation to consider the higher safety level. Dynamic soil properties are estimated from the limited information available. The response analysis is performed using a FEM mesh with a limited subsoil foundation depth whereby the base motion is determined by applying a deconvolution of the deep-stratum free-field response. An effective acceleration value for the dam slope is calculated by an appropriate procedure for subsequent use in pseudo-static slope stability analyses.
An alternative slope design methodology to prevent slope failures due to rainfall infiltration
Authors: Lee S.R.  , Kim Y.K.  , Kwon H.S.  , Hwang D.
Published: February 2025

Qutie frequent slope failures have been occurred not only in natural slopes but also in engieered slopes. Although engineered slopes such as excavated and compacted slopes were carefully designed and well constructed, unexpected rainfall storms cause many slopes to failure. Nevertheless, we have to do our best to properly consider the real situations in the design. The state of slope safety changes as the rainfall infiltrates into the slope. It induces the pore-water pressure to increase. At present, there is no standard slope design methodology to properly consider the effects of rainfall infiltration. In the current specification of slope design, the surface water-table condition is suggested to prevent the slope failures in case of rainfall condition. However, the surface water-table condition is not relevant to present the real situation, in which only near the surface of slope becomes saturated unless the slope is highly permeable and has initially high water-table. Moreover improper saturated soil properties are generally used in the slope design process. Therefore the design results do not assure the slope stability during or after the rainfall. In this paper, an alternative slope design methodology is suggested to consider the real infiltration condition. It combines not only the local rainfall characteristics but also local permeability of slopes. This suggested slope design methodology includes the main factors affecting the slope stability such as; (1) reasonable initial profile of matric suction, (2) soil-water characteristic curve (SWCC) and permeability function, (3) prolonged rainfall condition, (4) nonlinear shear strength criterion, (5) shallow or deep (circular) slope failure mode, etc.
Landslide triggering experiment in a steep forested slope in Switzerland
Authors: Springman Sarah  , Kienzler Peter  , Casini Francesca  , Askarinejad Amin
Published: February 2025

A landslide triggering experiment was carried out on a 37°– 40° steep forest slope in North-East Switzerland by sprinkling water artificially to represent an extreme rainfall event. This project is part of a multidisciplinary collaboration, which includes geotechnical engineering, hydrology, hydrogeology, forest engineering, geophysics and photogrammetry. A three dimensional model of the ground was developed from non-invasive geophysical surveys, insitu probing, combined sprinkling and dye tracer tests and shallow test pits. Laboratory tests were carried out on undisturbed samples under various degrees of saturation This paper mainly focuses on the characterisation of the site.
A numerical study of a deep excavation in soft clay in Norway-comparison of 2D and 3D analyses
Authors: Tørum E.  , Kirkebø S.  , Athanasiu C.
Published: February 2025

The Norwegian Public Roads Administration is planning a main road northbound from the city of Trondheim in Norway. This comprises a tunnel through soft sensitive clay (partly quick clay) based on the cut-and-cover method. To limit deformations, the excavation is designed with steel sheet pile walls, ribs of jet grouted piles and steel struts. Comparison of 2D and 3D FEM analyses has been performed. The paper comprises evaluations of all construction sequences down to the final excavation level on short term loading. Soil-structure interaction and bottom heave failure of the excavation pit is given emphasize.
Design of multiple deep non-circular tunnel linings
Authors: Fotieva N.N.  , Bulychev N.S.  , Deev P.V.  , Firsanov E.S.
Published: February 2025

A method for the design of multiple deep tunnel linings of arbitrary cross-section shapes (with a single axis of symmetry) under the actions of the rocks own weight and underground water pressure is described in the paper. The method is based on investigations of interaction of tunnel linings and the surrounding rock mass as elements of a united deformable system and on new analytical solutions of corresponding plane problems of elasticity theory. The method is realized in the corresponding software.
Modélisation 3D du creusement de tunnel par tunnelier à front pressurisé – Validation sur 3 cas d'études
Authors: Demagh R.  , Emeriault F.  , Kastner R.
Published: February 2025

La réalisation de tunnels à faible profondeur en site urbain nécessite une évaluation préalable des effets du creusement sur les ouvrages existants. Dans le cas du creusement par tunnelier à front pressurisé, les différentes opérations réalisées par le tunnelier rendent très complexe une modélisation numérique complète du problème et donc l'évaluation des mouvements induits. Une procédure de simulation tridimensionnelle, utilisant le code en différences finies Flac-3D, prenant en compte de manière explicite les principales sources de mouvements dans le massif encaissant est proposée et appliquée dans trois cas de chantiers supports, différents par le type de pressurisation du front, la nature des sols traversés ou leurs caractéristiques mécaniques. La confrontation des résultats de simulation numérique avec les mesures in-situ montre que la procédure de simulation 3D proposée est pertinente, en particulier dans la représentation adoptée pour les différentes opérations réalisées par le tunnelier (excavation, soutènement du front de taille, avancement, pose du revêtement, injection du vide annulaire, ...).
Mechanical behavior of twin tunnel
Authors: Lee S.-W.  , Choi J.-I.  , Shim S.-H.  , Cho G.-C.  , Hong E.-S.
Published: February 2025

The application of twin tunnel with considerably close center distance has recently been increased. In this study, the scaled model tests of closely-spaced twin tunnel by using homogeneous material are performed and induced displacements are measured around the tunnel openings during and after excavation. The influence of center distance between tunnels and coefficient of earth pressure (K) on the mechanical behavior of closely-spaced twin tunnel are investigated. Two-dimensional numerical simulations by using the Particle Flow Code (PFC) are also conducted to supplement and verify the scaled model test results. The results are expressed by the induced displacement, progress of crack and load around the tunnel openings during excavation and at failure. The results show that the numerical results are found in a good agreement with the model test results indicating the PFC could be used to investigate the mechanical behavior of twin tunnel. The analyses of induced displacements during excavation show that the additional displacement of the first excavated tunnel induced by the excavation of subsequently excavated tunnel decreases as the center distance between tunnels is increased until the center to center distance is two times of tunnel diameter (2D). Beyond this distance, however the additional displacement has become stabilized. The results of the influence of K on the mechanical behavior of twin tunnel show that the general aspect of displacement and crack progress changes significantly depending on K. In addition, the weak zone in view of stability varies as well.
Settlement characteristics of full scale test embankment on soft Bangkok clay improved with Thermo-PVD and stiffened deep cement mixing piles
Authors: Bergado D.T.  , Phienwej N.  , Jamsawang P.  , Ramana G.V.  , Lin S.S.  , Abuel-Naga H.M.
Published: February 2025

The full scale test embankments were constructed on improved soft Bangkok clay in Thailand. The ground improvement methods consist of thermal treatment with drainage (Thermo-PVD) and reinforced deep cement mixing (SDCM). This study aimed to compare the reduction of settlements among those aforementioned full scale test embankments. The observed settlements data in field situation also discussed by means of rate and magnitude of the settlements. The Thermo-PVD treated embankment foundation indicated both higher rate and magnitude of settlements. Moreover, the SDCM reduced the settlement magnitude by 40% compared to the DCM improvement. Finally, these soft ground improvement techniques are recommended as viable methods for future geotechnical construction projects.
Prediction of surface deformations, caused by shallow service tunnels construction activities in Moscow
Authors: Ilyichev V.A.  , Konovalov P.A.  , Nikiforova N.S.  , Tupikov M.M.
Published: February 2025

In recent years Moscow has seen construction of shallow (up to 8.0 m deep) service 3-4 m dia tunnels for major underground complexes and renovation of existing tunnel networks. In order to preserve the existing buildings, utility lines, pedestrian walks and roads prediction of surface deformations is required.
Soutènement d'une fouille profonde, avec vérinage, au pied d'immeubles de grande hauteur à Monaco
Authors: Lavisse J.  , de Lavernée P.
Published: February 2025

La construction de la résidence St Georges à Monaco a nécessité l'ouverture d'une fouille de 30 m de dénivelé à proximité immédiate d'immeubles existants de grande hauteur. Le site étant très pentu, la fouille était très dissymétrique. L'interdiction d'utiliser les tréfonds privés avoisinants pour ancrer le soutènement en phases provisoires comme définitives, et l'impossibilité de procéder à un butonnage classique du fait de la dissymétrie a obligé à concevoir un bâtiment autostable en phase service et à mettre en place en phases de travaux des butons inclinés.
Influence of the rate of construction and of rock mass strength reduction on the stability of deep cuts in marl
Authors: Štern K.
Published: February 2025

During geotechnical monitoring of anchored retaining structure and marl rock mass in conditions where marl is sensitive to variations in water content, the question appeared if design investigations in such cases generally overestimate strength and stiffness parameters. Another question is concerned with the extent and amount of changes in rock mass properties and with the influence of the construction rate and sequence. It was found out that the process of secondary humidification of the slope is directly related to the progress of works. The recorded increase of marl water content was on average 1.2% and the average decrease of uniaxial compressive strength was 28 %.
Dynamic soil properties estimated from downhole array data recorded at the Kashiwazaki-Kariwa nuclear facility in the 2007 Niigata-ken Chuetsu-oki earthquakes
Authors: Tokimatsu K.  , Arai H.
Published: February 2025

Dynamic properties of soil deposits at two sites (one near Unit 5 and the other near the Service Hall) at the Kashiwazaki-Kariwa nuclear power plant were back calculated using strong motion recordings obtained during the 2007 Niigata-ken Chuetsu-oki earthquakes. The method used to figure this inversion was genetic algorithm, coupled with a one-dimensional equivalent linear response analysis, in which damping ratios will vary with the Fourier shear strain amplitude in the frequency domain. Our back-analysis has demonstrated that the surface layer at the Service Hall consisting of Holocene and Pleistocene dune sands showed strong nonlinear behavior during the main shock, with the underlying Pliocene Nishiyama Formation remaining elastic. The Pleistocene Yasuda Formation occurring near the ground surface at Unit 5, as well as the underlying Nishiyama and Shiiya Formations, also remained nearly elastic, but exhibited higher damping ratios. It is believed that the different dynamic soil behavior between the two sites may have led to the strikingly different site amplification between the two sites during the main shock.
Experimental study to correlate change in the structural frequency and foundation soil water content
Authors: González L.  , Boroschek R.  , Verdugo G.
Published: February 2025

The existence of an important infrastructure stock with extended usage periods that has suffered damage or collapse under conditions of normal functioning or external actions that are slightly higher than normal has raised the interest of the scientific community for the development of a structural health monitoring technique. It has been identified that the variation of these dynamic parameters depends mainly on the mass and stiffness of the structure. However, it has been observed recently that temperature, rain and wind also affect the dynamic parameters of the system. In practice, it is difficult to determine if the observed changes in these parameters are caused only due to structural effects, or also due to climatic changes. This article presents results of a study conducted to investigate the effect of soil water content in the natural frequency of a scale soil–structure system.
Comparison of Dynamic and Static Pile Testing, a Case Study
Authors: Riihimäki Teemu
Published: February 2025

Pile capacities can be estimated basically with two different kind of load test: dynamic and static load test. The comparison between these test results is often impossible to do, because usually only one method is used per site. This paper presents a case study where both methods were used and results compared. The test results showed that the dynamic test with or without CAPWAP analysis correlated very well with static load test results. Test results proved that it is possible to use end bearing small diameter steel pipe piles in the area and dynamic pile load test is cost efficient compared to the static load test.
Properties controlling the resistance to abrasion and erosion of stabilized sandy soils using non-traditional additives
Authors: Mgangira M.B.
Published: February 2025

Sands are generally loose with very little natural binding capacity to resist wheel traction forces and therefore do not generally meet the traditional requirements of wearing course materials for unpaved roads unless they are subjected to some form of treatment. On the basis of the sand properties and performance before and after treatment, measured by the abrasion and erosion tests, the factors that controlled the effectiveness of the stabilization were established. It was found that particle size distribution, Atterberg limit values as determined on material passing the 0.075 mm sieve, particle characteristics such as grain structure morphology determined by SEM are the contributing factors to the difference in performance exhibited by the sand samples.
Monitoring of deep excavations in Istanbul
Authors: Saglamer A.  , Aslay Z.
Published: February 2025

As a cosmopolitan city, Istanbul has a population over 12 million. Thus, new residences are needed to be built. However, there is also lack of space for buildings, especially for car parks and shops, so deep excavations are unavoidable. Two deep excavations neighboring important buildings are being excavated in Istanbul. The soil profiles of both of the sites consist of recent fill at the surface and Thrace formation below. However, although it was not observed during the borings, shale layer has also been encountered during excavation. Since the retaining system was designed depending on the soil profile at the site, when the shale layer appeared at the façade revisions has been done during process. It was an advantage to have monitoring before and during the excavation, to prevent any harmful movement. The retaining system and its elements will be presented in details in the paper, with the importance of the inclinometers, what they had showed and how did they prevented a collapse.
Innovative dynamic compaction techniques & integrated compaction control methods
Authors: Adam D.  , Brandl H.
Published: February 2025

The paper provides a state of the art overview of compaction technologies and moreover integrated vibration based measurement systems used on dynamic rollers and heavy tamping technique to continuously measure soil properties during and after earthwork compaction. Roller measurement values have evolved towards the estimation of more mechanistic soil parameters, e.g., stiffness modulus. Independent assessment of these measurement values has proven their efficacy. Heavy tamping is a deep dynamic compaction technique and has been increasingly used since beginning of the Seventies of the last century. The authors report on in situ measurements and theoretical investigations referring to the decay of free soil vibrations caused by the falling weight after each impact. The Rapid Impact Compactor is an innovative dynamic compaction device based on the piling hammer technology used to increase the bearing capacity of soils through controlled impacts. This ground improvement technique allied to dynamic compaction has been recently introduced in Central Europe. An integrated measurement system is currently under development.
Groutability and effectiveness of microfine cement grouts
Authors: Christodoulou D.N.  , Droudakis A.I.  , Pantazopoulos I.A.  , Markou I.N.  , Atmatzidis D.K.
Published: February 2025

A laboratory investigation was conducted in order to evaluate the properties, the groutability and the effectiveness of microfine cements. Four gradations from CEM II/B-M (according to EN 197-1) type of cement were used having nominal maximum grain sizes of 100 μm, 40 μm, 20 μm and 10 μm. The properties of suspensions, with water to cement ratios of 1:1, 2:1 and 3:1 by weight, were determined in terms of viscosity, bleeding, setting times and unconfined compression strength. Groutability and effectiveness were evaluated by conducting one-dimensional injections into five different, clean sands using three specially constructed devices. The effectiveness of cement suspensions was quantified by conducting unconfined compression, triaxial compression and permeability tests on grouted sand specimens. Groutability of cement suspensions increases with increasing cement fineness and water to cement ratio. Microfine cement suspensions with water to cement ratios of 2:1 and 3:1 can penetrate into medium to fine sands. Groutability predictions by conventional criteria are not always confirmed by laboratory injections. Sands grouted with microfine cements obtained unconfined compression strength values of up to 3 MPa and, in terms of the Mohr-Coulomb failure criterion, exhibited significant cohesion (up to 1360 kPa). The permeability coefficient of the sands was reduced by up to 5 orders of magnitude.
Effect of electric potential on nanoiron particles delivery for pentachlorophenol remediation in low permeability soil
Authors: Reddy K.R.  , Karri M.R.
Published: February 2025

This paper examines the delivery of nanoscale zero valent iron particles (nanoiron) under different electric potentials for the remediation of a low permeable kaolin soil spiked with pentachlorophenol (1000 mg/kg of dry soil). Bench-scale electrokinetic experiments were conducted using nanoiron suspension (50-300 nm particle size; 5 g/L and 10 g/L concentrations) in the anode and applying different electric potentials (1 and 2 VDC/cm). The iron concentrations in the soil increased with increased nanoiron concentration from 5 g/L to 10 g/L in the experiments conducted with 1 VDC/cm voltage gradient for a total duration of 427 hours. The iron concentrations in the soil were further increased with higher voltage gradient (2 VDC/cm)increased operating duration (938 hours). As the testing progressed, the transport of nanoiron particles was limited by their aggregation, settlement and partial oxidation within the anode. The electrical current and electroosmotic flow were higher in the experiments conducted with 1 VDC/cm as compared to that of experiments with 2 VDC/cm, possibly due to the combined effects of faster acidification of the soil and rapid oxidation of nanoiron particles under higher voltage gradient. PCP was partially reduced (40-50%) in all of the experiments. PCP was completely reduced near the cathode due to abiotic reductive dechlorination within the cathode. Improved strategies are needed to prevent aggregation, settlement and oxidation of nanoiron particles for enhanced remediation of PCP in soils.
Foundation improvement for a building on loess soil
Authors: Mulabdic M.  , Minazek K.
Published: February 2025

A high school two store building made of bricks, about 200 years old, suffered from settlement caused by increase of water content in loess soil, as a result of leakage of sewage system. Soil improvement with use of jet-grouting was designed and applied as a measure of foundation improvement and suppression of further settlement and fissuring of the building. Grouting was executed on outer and inner foundations, in the region affected by settlement, to the depth of 12 m under surface. In order to assure most suitable grouting technique a trial piles of jet-grouting were executed, aside from the object, using different pressures, direction of jet and time of jet action in place. With the pressure of 400 bar columns of 55 cm in diameter were obtained and it was accepted as a good result having in mind distance and spacing of boreholes under foundation. During execution of soil improvement measurement of soil deformation with depth and measurement of cracks in walls was performed, as well as topographic measurement of points on building. Before start of jet –grouting tunnels under building were filled with special concrete through the borehole from the surface. Comprehensive measurement of soil deformations, settlement and cracks on the building was performed before, during and after remediation work. Movements of the building ceased some time after the work was done, indicating that remediation work was successful.
Fundamental factors for the strength control of lime treated soils
Authors: Consoli Nilo Cesar  , da Silva Lopes Junior Luizmar  , Maghous Samir  , Schnaid Fernando
Published: February 2025

The treatment of soils with lime finds application in the construction of pavement base layers and as a support layer for shallow foundations. However, there are no dosage methodologies based on rational criteria as exist in the case of the concrete, where the water/cement ratio plays a fundamental role in the assessment of the target strength, and in the case of soil-cement technology, where the voids/cement ratio is shown to be a good parameter for the estimation of unconfined compression strength. This study therefore aims to quantify the influence of the amount of lime, the porosity and the moisture content on the strength of a lime treated clayey soil, as well as to evaluate the use of a voids/lime ratio to assess its unconfined compression strength. Results show that the unconfined compression strength increased linearly with the increase in the lime content as well as with the reduction in porosity of the compacted mixture. The change in moisture content has not introduced a significant effect on the unconfined compression strength of mixtures compacted at the same dry density. It has been shown that, for the soil-lime mixture in an unsaturated state (which is usual for compacted fills), the voids/lime ratio, defined as the ratio between the porosity of the compacted mixture and the volumetric lime content, is an appropriate parameter to estimate the unconfined compression strength of the soil-lime mixture studied.
Chemical effects on the performance of soil-bentonite cut-off walls for in-situ containment
Authors: Katsumi T.  , Inui T.  , Kamon M.
Published: February 2025

Containment with soil-bentonite (SB) cut-off walls is a valid method to prevent the contaminants in subsurface environment from migrating in the aquifer. This paper addresses the laboratory testing results on the hydraulic barrier performance of SB focusing on its chemical compatibility, since the swelling of bentonite, to which the low hydraulic conductivity (k) of the SB is attributed, is significantly influenced by the chemical species and their concentrations in the soil and groundwater. Flexible-wall hydraulic conductivity tests were conducted for SB specimens, which were processed from three different types of soils, exposed to various types and concentrations of chemicals (calcium chloride, heavy fuel oil, ethanol, and/or seawater) in the permeant and/or in the pore water of original soil. For the SB specimens in which the pore water of original soil did not contain such chemicals and thus the sufficient bentonite hydration was expected to occur, k values were not significantly increased even when permeated with the relatively aggressive chemical solutions such as 1.0 mol/L CaCl2or 50%-concentration ethanol solution. In contrast, the SB specimens containing CaCl2in the pore water had the relatively higher k values. For the CaCl2concentrations higher than 0.05 mol/L or the seawater, approximately one order of magnitude higher k values were obtained. The excellent linear correlation between log k and swelling pressure of the SB specimens containing various types and concentrations of chemicals implies that the swelling pressure can be a good indicator for the hydraulic barrier performance of the SB.
Danger of flooding – New safety measures in dike construction by using geosynthetics
Authors: Heerten G.  , Heibaum M.  , Haselsteiner R.  , Werth K.
Published: February 2025

The risk of dyke failure is mainly given in cases of critical water saturation (due to non effective sealing or drainage zone) and dyke crest overtopping (due to undervalued crest height, settlements or higher design water levels than expected). Safe cross-sections according to state of the art are characterized by the successful use of geosynthetic clay liners as alternative dike sealing element. After several years of service as sealing element at dikes in Germany, geosynthetic clay liners (GCLs) have been exhumed and examined. The results of these in-service GCL analyses confirm the effectiveness. As an alternative to conventional construction designs for dike crest overflow, an enhanced geosynthetic application of soil reinforcement is taken into account. Different construction methods for the design of overflow dikes are presented. Some of the presented constructions were tested within a research project at Institute of Hydraulic and Water Resources Engineering of the Technische Universitaet Muenchen. The results of these tests are briefly summarised.
Identifying and mitigating ground risk on large Water Industry Asset Management Programmes in the UK
Authors: Eddleston Malcolm  , Holme Elaine
Published: February 2025

Water industry clients in the United Kingdom (UK) require assistance from consulting and contracting partners in delivering large programmes of work. Many of the projects involved in these programmes require deep excavations and major structures which impose load on the ground in some way. The ground engineering elements of these projects is an area where the risks are high and where projects characteristically have unknown elements. This paper will explain how ground risk management is used on large programmes to identify high risk projects. Once identified, systems are put in place to effectively protect schedules and reduce risk through optimising design solutions. This is done by incorporating risk reviews from technical specialists at the appropriate level.
Risk Management for Underground Construction
Authors: Chin C.T.  , Chao H.C.
Published: February 2025

In engineering practice, geotechnical uncertainties are often coped with by various codes and standards. However, uncertainties are not invariant for all projects and thus design and construction codes and standards do not necessarily always satisfy the requirement. It is not uncommon severe losses and impacts as a result of construction failure attribute to geotechnical uncertainties. Therefor, engineering risk management has been widely discussed in recent years. In Taiwan, the Airport Link Contract IATX03 is one of the projects formally apply this technique in the management scheme. This article introduces the fundamentals of engineering risk management and demonstrates its application by the case of underpinning of this project.
Soil properties of the shallow type methane hydrate-bearing sediments in the Lake Baikal
Authors: Kataoka S.  , Yamashita S.  , Suzuki T.  , Kawaguchi T.
Published: February 2025

The purpose of this study is to understand the soil properties of grounds contained shallow type methane hydrates. For this study, the surveys were conducted in the Lake Baikal, Russia in 2005-2007, existed shallow type methane hydrates, and the several kinds of tests (physical and mechanical tests) were preformed for the lake-bottom sediments. The tested samples were collected from the mud volcano ground contained shallow type methane hydrates and the reference ground at same area. From the results, it was found that the reference samples in the Lake Baikal have no marked differences in the soil properties of the sediment obtained from other sea-bottom areas. On the other hand, the strengths and shear modulus of the mud volcano samples obtained from the on-board tests were lower than those of the reference samples.
Effects of large cyclic and creep loading on peak strength of compacted gravel in triaxial compression tests
Authors: Maqbool S.  , Koseki J.
Published: February 2025

Effects of large cyclic and creep loading on peak strength of compacted gravel was investigated by performing a series of four triaxial compression tests using large scale apparatus in Koseki Laboratory, The University of Tokyo. The specimens were rectangular prismatic with dimensions of 50 cm high and 23.5 cm times 23.5 cm in cross-section. To measure the major principle stress σ1, a load cell is located just above the top cap inside the triaxial cell in order to eliminate the effects of piston friction. The major principle strain ϵ1was measured not only externally but also locally with three pairs of vertical local deformation transducers (LDTs). Minor principle strain, ϵ3was measured by three pairs of horizontal local deformation transducers (H-LDTs). Chiba gravel (Dmax= 38 mm, D50= 6 mm and Uc= 33) was used as the test material. The specimens were prepared by employing automatic dynamic compaction and keeping dry densities within the range of 1.91-1.98 g/cm3. During monotonic shearing stage after large cyclic as well as creep loading stages, sudden increase in the shear stress level without any considerable increase in axial strain was observed. From this study, it is concluded that if the gravel is compacted to a certain degree, there will be no significant effect of large cyclic or creep loading history on its peak strength.
General Report TS-3A: Instrumentation in Geotechnical Engineering
Authors: Iwasaki Yoshinori
Published: February 2025

Sensors for geotechnical engineering are developing in the last decades. General report consists of two parts. The first part is to review recently developing technologies like MEMS (Micro Electro Mechanical Systems), GPS (Global Positioning Systems), BOTDR (Brillouin Optical Fiber Reflectometry), as well as wireless system. The second part contains the overview of the 11 papers that were submitted to the 17th ICSMGE.
Estimation of high suction values in unsaturated soils using conventional tensiometer
Authors: Vanapalli Sai K.  , Oh Won Taek
Published: February 2025

A simple method is proposed to estimate suction values in unsaturated soils ranging from 1,200 to 60,000 kPa in this paper using the conventional tensiometer results and the Kondner (1963) hyperbolic model. The proposed method uses the initial tangent value of suction versus time response in the suction range of 0 to 50 kPa for estimating the equilibration suction value. The model was tested on the published results of suction versus time response of high capacity tensiometers from the literature and an experimental program undertaken on compacted glacial till specimens with reasonably good results.
Predicting consolidation settlements using small-strain, large-strain and stress path methods
Authors: Bo M.W.  , Fabius M.  , Chu J.  , Arulrajah A.
Published: February 2025

Primary consolidation settlement has traditionally been estimated using 1-D linear elastic consolidation theory with various assumptions. Due to theoretical limitations, measured settlements in many cases are not in agreement with those predicted. One of the major limitations is the application of small strain theory to large strain deformation. Another limitation is the stress dependent behaviour of soil deformation. This paper summarizes the various factors affecting settlement predictions and compares results from conventional 1-D small strain theory, finite different modelling, finite element modelling applying large strain theory and the stress path method. The results are compared with actual field monitoring data from recent projects in Singapore at the Changi East Land Reclamation and Ground Improvement Project. The reasons for variations in measured results are also discussed.
Some models of soil behaviour for evaluation of consolidation settlement in clays
Authors: Rotaru A.  , Răileanu P.
Published: February 2025

Nowadays geotechnical processes are used in stabilizing ground or to improve the capacity of foundations. The major technical risk for any civil engineering works is in the ground. Therefore it is necessary to investigate the geological and geotechnical conditions on any site in order to produce ground treatment and improvement. A conceptual ground model will identify the nature of the ground beneath the site. Modeling forms a very important part of engineering design but many engineers don't take into account either the fact that they are making assumptions as part of the modeling or the nature and consequences of those assumptions. The paper develops some models of soil behaviour for evaluation of consolidation settlement in clays and is attempting to explain how combining distinct soil models will improve the final accuracy of the results because the final model must be a simplification of the reality. If we can estimate the pore pressures generated by the load and the soil stiffness which controls the vertical strains that develop as the pore pressure dissipate, than we can combine these estimates to evaluate the consolidation settlement. The procedure for evaluation of consolidation settlement in clays combines elements of a number of distinct soil models: an elastic model to calculate the total stress changes which, for a clay layer of uniform stiffness and of either infinite depth or underlain by a rigid layer, are not actually dependent on that stiffness; an empirical model to link total stress changes with changes in pore pressure; and a one-dimensional model for conversion of pore pressure change to settlement. Each of these models introduces its own simplifications which could be: constant pore pressure parameter, isotopic elasticity, constant oedometric stiffness, and variable stiffness layered soil. In terms of a rheological model, the fundamental element consists of a spring, representing the recoverable deformation, in series with a rate process dashpot representing the irrecoverable deformation.
Calcul analytique des contraintes sous une plaque rigide en fonction de la nature et de l'état du sol
Authors: Ejjaaouani H.  , Shakhirev V.  , Magnan J.-P.
Published: February 2025

Cette communication présente un modèle tridimensionnel de calcul dans lequel les dimensions de la zone influencée par une charge surfacique sont définies par un angle de diffusion des contraintes β, qui dépend de la nature du sol et de certaines caractéristiques d'état comme la densité et l'indice des vides. La répartition des incréments de contrainte verticale dans chaque plan horizontal du massif de sol est décrite par une loi polynômiale du troisième degré. Des expressions analytiques sont données pour le cas d'une semelle rigide circulaire et celui d'une semelle rigide rectangulaire, ainsi que des exemples de calcul.
Elasto-plastic description of mechanical behavior of silt improved by lime
Authors: Nakano M.  , Yamada E.
Published: February 2025

Mechanical tests were carried out on compacted specimens of Kira converted into pebble form by crushing and mixing with lime with the objective of effective utilization of fine particle silica sand Kira, which is a by-product of the ceramics industry, as a geomaterial. Furthermore, the mechanical behavior was reproduced using the SYS Cam-clay model, which describes the mechanisms of the soil skeleton structure (structure, overconsolidation, and anisotropy), and was explained based on the concept of skeleton structure. The following are our major conclusions for the present research.
Non-linear viscous behaviour of undrained Bangkok clay
Authors: Likitlersuang S.  , Chompoorat T.
Published: February 2025

In Newtonian mechanics, shear resistance of material is assumed to be linear proportion to shear rate, in which the proportional constant is defined as a coefficient of viscosity. However, the rate-dependent or viscous behaviour of soil can not simply assume to be linear, but it can be explained using Rate Process Theory (Mitchell and Soga, 2005). The rate effect on shear strength of soil and creep settlement are two well-known examples of the viscous behaviour of soil. In addition, Vaid and Campanella (1977) have shown an experimental evidence of the rate effect on the shear strength of Haney Clay. This paper aims to present the non-linear viscous behaviour of Bangkok Clay using an experiment programme and modelling. The experiments are performed on normally consolidated clay which taken from the Centre of Bangkok. All specimens are isotropically consolidated and undrained compression sheared varying with five different shear rates. The rate-dependent hyperplasticity model (Puzrin and Houlsby, 2003 and Likitlersuang and Houlsby, 2006) based on Rate Process Theory are employed in this study. The model is calibrated against the undrained triaxial sheared tests of Bangkok Clay.
Geomechanical model for sediment profiles
Authors: Christensen S.O.  , Svanø G.  , Skomedal E.
Published: February 2025

Idealized sediment profiles based on the tangent modulus concept have been developed over some years. The aim of this study was to extend and refine this model. A methodology based on an existing geomechanical model for estimation of porosity and density profiles for natural sediments, including sands and sandstones, and clays and claystones or shales have been developed. This paper describes some of the basis for the development of the geomechanical model, interpretation of laboratory tests and field data from wells, and some results using the model. The bounding values of the controlling parameters are estimated accounting for geotechnical experience of sand and clay, and by interpretation of selected borehole profiles and well logs. The expected porosity trend with depth can now be predicted for normally consolidated profiles or for profiles with known stress history. The results from analyses with program MECAD (MEchanical Compaction And Diagenesis) show that the model works satisfactorily. The computed results show good agreement with observed data and confirm the possibility of the model to correctly reproduce mechanical sedimentary compaction. Creep effects have been evaluated, and creep has little influence on the reduction in porosity for sediments with porosity less than 30%. The effect may be substantial for sediments with high porosity.
Influence of mineralogical composition on geotechnical properties
Authors: Tiwari B.  , Dhungana I.
Published: February 2025

To evaluate the geotechnical properties of a soil mass, different soil specimens were prepared in the lab by mixing various proportions of quartz, smectite, and illite. Liquid limit, plastic limit, and volume change behavior in terms of compression and swelling indices were measured according to the procedure mentioned in the respective ASTM methods. Those minerals are considered as the most common minerals that are found in expansive soils that include mudstone/clay stone, marl and shale. Such expansive soils are always considered as problematic soils in geotechnical engineering. The results show that plasticity index and liquid limit depend on the proportion of smectite and total clay content. A parabolic relationship could be observed between the liquid limit and proportion of smectite. Smectite is mainly controlling the plasticity characteristics. Likewise, volume change properties also depend on the proportion of smectite and liquid limit. A parabolic relationship was observed between the compression index and proportion of smectite, whereas a linear relationship was observed between the liquid limit and compression index. The results clearly show that we can estimate the coefficient of consolidation, and compression and swelling indices of a soil mass with reasonable accuracy with liquid limit and proportion of dominant clay mineral. This finding has a great significance in the geotechnical engineering because with a small amount of soil that can be collected from a boring core, we will be able to evaluate liquid limit, mineralogical composition, and clay content. Those parameters can be used to estimate the compressibility and hydraulic conductivity of a soil mass. They are very important in numerical simulation, foundation design, and many other applications in geotechnical engineering.
Practical relevance of collapse behaviour and microstructure of loess soils in Afghanistan
Authors: Meier C.  , Boley C.  , Zou Y.
Published: February 2025

Since 2001, the NATO has been built Camps for ISAF troops in Afghanistan. Especially in the North of Afghanistan, Germany, as part of the NATO, is building camps in Mazar-e-Sharif, Kabul and Kunduz. The soil in this area mainly consists of alluvial loess from the surrounding mountains.
Experimental and numerical investigations of dissolution of gypsum in gypsiferrous Iraqi soils
Authors: Al-Farouk Omar  , Al-Damluji S.  , Al-Obaidi Anwar Loay M.  , Al-Omari Raid Ramzi  , Al-Ani Mohamed Majid  , Fattah Mohamed Yousef
Published: February 2025

Gypseous soils are distributed in many regions in Iraq and other countries. Large damages that affect structures founded and constructed in or on them occur mainly due to the dissolution of the cementing gypsum. The change in porosity with time is studied herein. Laboratory oedometer permeability leaching tests are conducted using sandy soils with gypsum contents greater than sixty percent brought from Khan-Thare, Iraq. Analyses reveal a high effect of dissolution of gypsum on the settlement of structures founded on them.
Installation damage of nonwoven polypropylene geotextiles
Authors: Atmatzidis D.K.  , Chrysikos D.A.  , Papaefstathiou I.M.
Published: February 2025

European standard ENV ISO 10722-1 specifies a test for comparative evaluation of the installation damage of geosynthetics. Tests were conducted according to ENV ISO 10722-1 on 32 nonwoven, polypropylene geotextiles with mass per unit area from 100 to 2200 g/m2and tensile strength from 8 to 125kN/m. The effects of number of loading cycles and aggregate hardness were also investigated. A very good correlation (R2≈0.90) was obtained between installation damage index values and mass per unit area of the geotextiles. The damage index values obtained for geotextiles with mass over 500g/m2ranged between 85% and 95% indicating very limited installation damage. The damage index values of geotextiles with mass less than 500g/m2ranged between 43% and 85% indicating a very strong effect of geotextile mass on installation damage. Aggregate hardness by itself may not be a good indicator of damage potential. Increasing load cycles results in increased damage potential.
In situ characterization of an old railway platform with DCP
Authors: Fortunato E.  , Pinelo A.  , Matos Fernandes M.
Published: February 2025

The elastic stiffness measured in situ is considered a good indicator of the performance of railway platforms. The deformation modulus obtained from the Plate Load Test (PLT) is commonly considered representative of that stiffness. Nevertheless, the PLT is a very expensive and time consuming test. Moreover, it is very difficult to perform when the purpose is to characterize ancient platforms of railway lines that must be maintained active during the renewal works. The Dynamic Cone Penetrometer (DCP) is a much cheaper and simpler test, traditionally used to control the compaction of soils and granular materials. The paper reports the experience of the combined use of PLT and DCP tests for characterizing the platform of the main railway line in Portugal (built in the XIXth century), which has recently been upgraded to high speed passenger trains and freight trains with higher maximum axle load. Correlations between the average resistance to penetration of the DCP and the deformation modulus from PLT are presented for coarse-grained and fine-grained soils. A criterion is proposed for the depth over which the DCP results should be averaged for correlation with the modulus from the PLT.