Óbuda University Bánki Donát Faculty
ÓBUDA UNIVERSITY
EKIK Hydro-Bio-Mechanical Systems Research Center


ISC6 conference:

Date: Sept. 26 to 30. 2021.

Location: Budapest Congress Center

Workshops: Hungarian Academy of Sciences

ISC6 participants:  174 in person  +  60-70 persons online

Paper no: more than 250

16 sessions, 22 invited lectures


Conference brochure


ISC6 logo

Sessions:

1. Statistical-risk-economical aspects
2. Tests in various soil types
3. Special soils special properties
4. Equipments, tests
5. Evaluation, verification, special modelling
6. Soil parameters from testing
7. Geophysics
8. Numerical modelling
9. Dams, dikes, embankments
10. Liquefaction
11. Case studies
12. Environmental
13. Piles
14. Rock, stiff clay, cavity, debris flow
15. Quality control, large areas
16. Sampling

 

ISC6 workshops:

Dissipation testing: Hydraulic fracturing, modelling and model fitting “Towards standardisation”

Date: 16h to 18h  September 26th 2021
Location: Hungarian Academy of Sciences or Budapest / Budapest Congress Centre / ONLINE
Date: September 26, 2021
Chair: Dr. K Rainer Massarsch
Secretary: Zbigniew Bednarczyk, Nadaprapha Binsaaeteh and dr. habil. Emőke Imre

Viewing of presentations

Memory workshop

Prof. János Józsa: Opening of Workshop on behalf of the Hungarian Academy of Sciences
1
Joek Peuchen, Fugro
Pore presssure dissipation tests for offshore geohazards - discussion

The focus is on sharing experience with offshore deployment of a step-tapered piezoprobe in clays. Piezoprobes have a track record of about 25 years. This includes operation in water depths of >1100m and push-in deployment to more than 400m below seafloor. The Fugro piezoprobe is 10mm, which is small compared to a piezocone. For clays, this step-tapered piezoprobe thus allows acquisition of t90 dissipation data within a fair amount of time, typically within 6 hours per test. Test interpretation for in situ equilibrium pore pressure in clay is based on 1/t or 1/√t data processing methods. Interpretation of results requires verification for possible soil-related data anomalies including: (1) stratification affecting pore pressure migration along the axis of the tool, (2) gas in soil interfering with pore pressure measurement and (3) distinction between excess pore pressure and measurement uncertainty.

2
K. Rainer Massarsch:
Pore water dissipation following pile driving in clay

The presentation describes different types of in-situ measurements with the aim of studying the effect of pile driving in soft clay. The topics discussed are:
• In-situ measurements at Ska-Edeby test site.
• Measurement of rapid pore water pressure changes at multiple levels.
• Horizontal earth pressure before, during and after pile driving.
• Estimation of pore water pressure increase due to pile driving.
• Hypothesis describing the rapid pore water dissipation after pile driving.

3
Diego Marchetti:
The dissipation test performed with the standard DMT, with the Medusa DMT, partial drainage

The Medusa DMT system allows the precise recording of the stress changes. The record after the stop of the penetration, in case of partial drainage, needs special procedure which is treated. The A reading is needed to be taken differently in this case.

4
Laurin Hauser, Helmut Schweiger:
Numerical study on cone penetration and the dissipation afterwards

The contribution to the workshops deals with the numerical simulation of cone penetration testing and the subsequent dissipation phase using the Particle Finite Element Method. Based on the successful recalculation of in-situ CPTu in silty deposits the dissipation behavior at the u1 and u2 position was investigated under different drainage conditions highlighting the relevance of the obtained t50 for the characterization of the occurring drainage behavior.

5
Osman, Ashraf:
Modelling of penetrometers

The presentation gave an overview of recent developments in predicting pore water pressure around CPTs. The presentation started with a brief introduction to recent analytical solutions and discusses some of their limitations. The presentation finishes by introducing an Eulerian-based finite element approach and shows its success in simulating CPTs.

 
6
Emoke Imre - Stephen Fityus - Lachlan Bates – Márton Hegedűs:

Dissipation tests in partly drained soils - evaluation of truncated data, real-time evaluation in embedded system

The pore water pressure dissipation test data of various sites, various types, both with relatively large and small t50 times were evaluated. Long and truncated tests with various filter positions were considered. The result indicates that the identification of coefficient of consolidation in “real time” is possible. The value c may become steady after a while, therefore, at a value being less than t50, it could theoretically be possible to stop the test, earlier than time t50. Results indicate that for filter position u3, tmin is the shortest.

 

Special soils and MSW – Prof. László Rétháti workshop – saline, quick soils, energy utilisation and biogas

Date: 14h to 17h  September 30th 2021
Location: Hungarian Academy of Sciences
Prof. Devendra Narain Singh (DNS) chair
Prof. Kornél Kovács co-chair
Secretaries: Quỳnh Hương Đặng, Nadaprapha Binsaaeteh, dr. Emőke Imre

Memory workshop
Opening on behalf of the Hungarian Academy of Sciences:
Prof. János Józsa
(a few words on Professor Rétháti)
The workshop allowed the participants an impressive insight into the opportunities of environmental engineering in different fields. Current research findings in soil pollution, landfill energy and effects of agricultural activities have been presented by experts. The atmosphere of the workshop enabled inspiring discussions following the presentations.”
1
Jean-Sébastien L'Heureux - NGI:
Sensitive/quick clay in Norway

The concept of quick clay is explained. The main in situ and laboratory testing tools are analysed and some slope stability issues are treated.
2
Szilvia Simon:
Surface salinization from deep source

The presentation introduces an example from Hungary where surface and shallow groundwater salinization is influenced by deep saline groundwater upwelling. It highlights that groundwater is a geological agent, contributing to several surface phenomena, such as extended soil and shallow groundwater salinization. The study reveals that in some cases hydrogeological characterization can be necessary to understand surface saline features.

3
Zsombor Illés:
Dispersive soils from geophysics viewpoint

Investigation of a subject usually means that the tools of some field of study are used in order to obtain information. When similar disciplines, such as geotechnics and soil sciences are evaluating the same object, the diverse ways of collecting information leads to different conclusions. However, they study the same subject, only from distinct points of view. In the case of lake Szappanos, the properties of the subsoil were measured by the equipment of soil sciences and geotechnical engineering, and the results and correlations of the different parameters are collected and evaluated in this paper.
4
János Lógó:
Topology optimization as tool for the analysis of flow problems

Optimization methods are presented and their use in fluid theory are included. Likely some fluid optimum modelling may explain the fast piping, which may include dynamic effects of the ground, the dyke and the effect of a vortex reaching the river bed.

5
Kornél Kovács:
A stimulating bacterium in the methane development, H2 production

The Hungarian Biotechnological Research in related to Renewable Energy is considered. The role of Hydrogen in biogas production is depicted.
6
Arif Mohammad:
Decomposition Characteristics of Municipal Solid Waste in a Bioreactor

 Bioreactor landfill, wherein leachate recirculation is practised, has emerged as a panacea that facilitates the rapid decomposition of municipal solid waste. This is achieved by controlling the prevailing conditions (viz., pH, moisture content, temperature, and nutrient requirement of microorganisms) properly to regulate the microbial metabolism. This technology is also instrumental to tackle the issues related to the scarcity of the land required to create or expand the new landfill by resorting to landfill mining. However, it should be realized that efficient monitoring of a fully functional bioreactor landfill is not so easy due to several operational constraints and environmental issues. Keeping this in view, several strategies, including destructive (sampling from landfill and followed by laboratory testing) and non-destructive (in situ) tests (cone penetration tests, multichannel analysis of surface waves) have been adopted to establish the rate of decomposition of municipal solid waste in a bioreactor landfill , located in Mumbai, India. Based on these results, a numerical model also has been developed by incorporating coupled thermo-hydro-bio-chemico-geomechanical phenomena to simulate the decomposition of municipal solid waste in landfill.
7
Emoke Imre et al:
Dike piping

Some cases of backward erosion/liquefaction piping are dscribed. These distinguish between usual sand boils and the ‘fast’ piping, the - possibly dynamic liquefaction induced – breach. The latter happens in a matter of minutes, whereas in the former emergency response measures can be effective. According to the presented case studies, the ‘fast’ piping failure has a typical pattern. This pattern can be explained by optimisation theory in fluid flow since the liquefied soil layer behaves as a fluid.
8
Viktória Parrag, Kornél Szalay:
Potential applications of hyperspectral imaging with a particular focus on the agriculture and food industry

The presentation gave a general introduction of hyperspectral imaging, its basic principle and a short overview of the application fields of the technology. In the second part current agri-food application projects has been presented including the detection of ragweed, dust sensing and visualisation in agriculture via video spectroscopy and the study of the spectral response of raspberry plants to different light conditions. Food safety and quality aspects have been discussed related to applications of hyperspectral imaging for the study of toxigenic Fusarium infection on cornmeal and the detection of cobweb disease infection on white button caps.
9
Ágnes Bálint:
Heavy metal pollution in soils along the Sajó, Hernád and Tisza rivers

The Sajó valley was a thriving industrial area 20-25 years ago, but in the early 1990s most of the factories closed down, but relatively little attention was paid to the pollution left behind. The Green Action Association carried out a comprehensive monitoring of the Sajó Valley in the early 1990s. This gave us the idea to carry out our work, as significant heavy metal pollution was found in the areas surveyed. It is very likely that this was mainly caused by heavy industry from the 19th century until the 1980s. Our aim was to investigate what heavy metal contamination might be found in some of the areas studied by the association 20 years later.
Six areas were selected as study sites for the soil samples, between Onód and Muhi (3 areas) and near Tiszaszederkény and Tiszagyulaháza (3 additional areas). Our soil samples were collected in November 2009 from the floodplains of the Sajó, Hernád and Tisza rivers at a depth of 0-40 cm.
10
Emőke Imre, G. Varga, T. Firgi, J. Ősz, László Tóth, et al:
Wind energy plant on the top of a landfill hill

The design of a wind turbine founded at the top of the Pusztazámor MSW (municipal solid waste) landfill hill, is based on the results of some large-scale compression tests and on some in-situ seismic, density and light falling weight deflectometer tests. In addition, some wind velocity measurements were made, to plan the number and size of the wind turbines. The compression curves of three waste samples showed stiffening with increasing depth and increasing degradation. The immediate settle-ment, the primary consolidation settlement and the creep settlement were separated. The settlement of the wind turbine under static load was determined with the Axis software in the function of the sub-grade modulus, the true value was inferred from the seismic test. The settlement was in the order of magnitude measured earlier in Karlsruhe for a somewhat smaller load.

 

Inverse problems – “Parameter identification, model validation, real-time systems”
– Professor Tom Schanz memory workshop –

Date: 10h30 to 13h  October 1 2021
Location: Hungarian Academy of Sciences
Maria Datcheva chair
Prof. Kornél Kovács co-chair
Secretaries: Nadaprapha Binsaaeteh, Emőke Imre

Memory workshop
Opening on behalf of the Hungarian Academy of Sciences:
Prof. János Józsa (a few words on Professor Schanz)
1
Peter Berzi:
Secant method in multidimension
In the secant method trial solutions for n+1 parameter vectors and the related residual or error vector are used to compute a new parameter vector. In the suggested method, from the new vector – using its coordinate components: n+1 parameter new vectors are formed. The convergence is better than the one of the Newton – Raphson method.

2
Sai Sri Harsha Vallurupalli, M.Sc. RUBochum:
Optimizing the design of retaining wall systems using multiobjective optimization strategies.
As increase in the constructions that are associated with the retaining wall systems, the need of maintaining the system economic within the permissible deflections and safety factor is significant.
  • This can be efficiently done by applying the optimization strategies (Genetic algorithms) to the wall design considering the wall deflections (mm), cost per linear meter (€/m) and safety factor as the objectives that are minimized and/or maximized accordingly.
  • Regression models have been developed in order to make the numerical calculations more flexible and to economize the computation effort & time.
  • Besides, the adaptive design optimization has been implemented in which the optimization can be associated with back-analysis which makes the procedure adaptable for the practical scenario.

3
Chenyang Zhao:
A hybrid model for mechanized tunnel excavation
To provide realistic predictions of mechanized tunnel excavation-induced ground movements, this research develops an innovative simulation technique called hybrid modeling that combines a detailed process-oriented finite element simulation (submodel) with the computational efficiency of metamodel (or surrogate model). This hybrid modeling approach has three levels to consider the uncertainty in soil properties and tunneling process parameters. The results show the capability of the proposed approach to provide reliable model responses in the near field around the tunnel with reduced computational costs

4
Elham Mahmoudi (Kavan Khaledi co-authors):
Reliability-based Robust Design Optimization of a Rock Salt Cavern
The fluctuating nature of renewable energy sources can be managed by storing the surplus of electrical energy in an appropriate reservoir. The excess electricity available during off-peak periods of consumption may be used to compress air or electrolyse Hydrogen. Afterwards, the pressurised gas is stored in the rock salt cavities and discharged to compensate for the energy shortage when required. The validation of rock salt caverns' short and long-term integrity and stability is a prerequisite in their design process. Because of the significant levels of uncertainties involved in the design procedure of such structures, a reliable design can be achieved by employing probabilistic approaches. Therefore, the numerical calculation is extended by statistical tools such as sensitivity analysis, probabilistic analysis, random field discretisation and reliability-based design to evaluate design parameters of the paramount need for practice.

5
Erick Baziw and Gerald Verbeek:
Inverse Theory – Concepts and Examples
This presentation outlines the general concepts of inverse theory with a focus on iterative forward modelling (IFM) and applied seismology. Comparisons are made to Bayesian recursive estimation where a posterior probability distribution is required. A downhole seismic testing example is provided where arrival times are inverted so that estimates of the interval velocities are obtained. Finally, the challenging problem of blind time variant seismic deconvolution is outlined and the necessity of IFM is demonstrated.

6
Arash Lavasan:
Optimized model validation based on monitoring data in mechanized tunneling: application to Milan Metro line 5
The concept of optimal experimental design (OED) enables determination of the most relevant monitoring set up among various strategies in order to allow an efficient parameter identification through an inverse analysis. In this frame, optimum monitoring set up is defined based on spatial and temporal sensitivity analyses to investigate the relevant zones in the domain and time scales to measure a certain item in the system. To validate the numerical model and to justify the applicability of this concept to a real case, the measured settlements in a shallow founded building that is induced by new double tube Milan metro line 5 is investigated.

7
Maria Datcheva:
Epilogue on Professor Schanz

8
Péter Bakucz:
Traffic and automated car development
In the chassis control engineering practice, it is often necessary to create a system that is
fully demonstrable or provable. In addition to provability, the completeness of the system is also important.
The system provability and completeness is necessarily for release processes. Therefore, in this work to be introduced a method, being defined the fully-provable and complete dynamical system for a traffic node based on the Euler-Lagrange equations. The fully provable means for a traffic node, that the geometry, the traffic dynamics, the boundaries and the  mathematical, algorithmical detection of the node are analyzed and quantified using Lagrangian densities.
The dynamics of a transport node is determined by discretizing the node and recording the movements of each transport participant in a "state - next state" system.
For product owners in chassis control software engineering and system engineering, the procedure may be important to be able to design a system where completeness and provability is ensured from the outset.
Full-provability means that the system is built using lagrange-densities in such a way that the combination of dynamic traffic correlations with boundary conditions and detection algorithmical know-how reaches an extremum.
The extremum is achieved by applying the principles of variation, aka the solution of the Euler-Lagrange partial differential equations with the system lagrangians based on the kinetical-, potential energies, boundary conditions  and algorithmical detectability issues.

 

Hungaricum: Gravitation – tide effects in groundwater and Eötvös torsion balance

Date: 14h to 16h, October 1, 2021
Location: Hungarian Academy of Sciences, Budapest.
Chair :  Péter Ván
Secretary: Nadaprapha Binsaaeteh, Emőke Imre

Memory workshop
Hungarian Academy of Sciences:
 Prof. János Józsa (a few words on Lóránd Eötvös)
Péter Ván chair
1
Bruno Meurers, Gábor Papp, Hannu Ruotsalainen, Judit Benedek and Roman Leonhardt (Austria):
Environmental effects in tilt and gravity residuals observed at Conrad Observatory (Austria)
The superconducting gravimeter (SG) GWR C025 has monitored the time variation in gravity at the Conrad Observatory (Austria) since autumn 2007. Two tiltmeters have operated continuously since spring 2016, namely a 5.5m long interferometric water level tiltmeter and a Lippmanntype 2D pendulum tilt sensor. The co-located and co-oriented set up enables a wide range of investigations because the tilts are sensitive to both geometrical solid Earth deformations and to gravity potential changes. The tide-free residuals of the SG and both tiltmeters clearly reflect the gravity and/or deformation effects associated with short- and long-term environmental processes and reveal a complex water transport process at the observatory site. Water accumulation on the terrain surface causes short-term (a few hours) effects which are clearly imaged by the SG gravity and N–S tilt residuals. Long-term (>a few days/weeks) tilt and gravity variations occur frequently after long-lasting rain, heavy rain or rapid snowmelt. Gravity and tilt residuals are associated with the same hydrological process but have different physical causes. SG gravity residuals reveal the gravitational effect of water mass transport, while modelling results exclude a purely gravitational source of the observed tilts. Tilt residuals show the response on surface loading instead. Tilts can be strongly affected by strain–tilt coupling (cavity effect). N–S tilt signals are much stronger than those of the E–W component, which is most probably due to the cavity effect of the 144m long tunnel being oriented in an E–W direction.

2
Peter Ván and Lajos Völgyesi:
Development of the Eötvös balances: automatization and readout
The improved sensitivity of the new equivalence principle measurements is based on the modernisation of an original instrument, a geophysical torsion balance. e survey the most important aspects of the technology, the automatisation of the rotation and the optical readout.

3
Szondy, György:
Eötvös balance, the everythingmeter: environmental effects
EPF-group is set up to repeat the famous Eötvös experiment with an original, high precision Eötvös torsion balance. The goal is to execute the measurements in fully automated way, using a state-of-the-art level of instrumentation and data processing. Instrumentation consists of executing several weeks of automated measurement program changing the orientation of the balance hourly, digital reading of the orientation and capturing and evaluating the scale of the balance, determining the equilibrium state from transient movements, the continuous measurement of the environment parameters (temperature, pressure, micro-seismic noise, tilt, magnetic field etc.) and detecting and logging human activity.

4
Peter Ván:
The weak equivalence principle and the 5th force: the new Eötvös experiment
The presentation surveys the history of the 5th force and gives the background and motivation the equivalence principle remeasurement with and original dipole type Eötvös instrument. The improved sensitivity lead to some interesting observations. Preliminary results are also shown.

5
György, Mező:
Data collection and data processing: the example of Eötvös balance networks
We are planning reorganizing the data collection of the Eötvös balance network using cloud based data collection. In the lecture we show examples how to  collect environmental sensors data based on the MQTT protocol. The sensors publish data to the MQTT’s broker and the cloud’s instance server subscribed to the broker collect the measured data into database. The data collecting system can be scaled up and it is also possible real-time data analysis on the cloud’s instances.

6
Gyula, Tóth:
Outlier tolerant automated inversion of noisy data captured on the Eötvös torsion balance
An original Eötvös-Pekár torsion balance is being used for the current re-measurement of the Eötvös-Pekár-Fekete (EPF) experiment. The double balance's arms are automatically rotated into different azimuths and two visual scales are read by analyzing the images captured at each second with two CCD cameras. For testing of the equivalence principle at each azimuth the scale reading of the damped position of the arms need to be determined from the time series of the readings. Since the arms initially bounce between delimiters and also an unknown number of readings are outliers, it is a challenge to get good fit for the last section with no bounces and with the rejection of a possibly high percent of outliers.
We present a RANSAC-based procedure and Python implementation that successfully solve this problem by using optionally four different damping models as well as the results of the fitting procedure at various azimuths. The process is fast, highly automated and robust, which is necessary, since for the EPF re-measurement we expect that about 1600 individual fits will be required for an input dataset of 6 million readings.

 

Hungaricum: Grading curve – Prof. Gyan Pande memory workshop – granular matter

Date: 16h to 20h  October 1st 2021
Location: Hungarian Academy of Sciences
Chair: Ágnes Bálint
Secretary: Nadaprapha Binsaaeteh,  Emőke Imre

Memory workshop  
Hungarian Academy of Sciences:
Prof. János Józsa (a few words on Professor Pande)
1
Hans-Georg Mattutis:
Shape effects, friction
H.-G. Matuttis is working mainly on the micro-mechanics of granular materials, with the discrete element method for dry and fluid-immersed systems. His main research objectives for dry systems are the effects of shape and friction on macroscopic quantities like strength and density. For fluid-immersed systems, his prevalent interest is on lubrication- and buoyancy effects between particles in fluids, to clarify the underlying mechanisms of liquefaction in earthquakes and landslides which are such common disaster phenomena in his adopted country Japan.

2
Wiebke Baille, Negar Rahemi, Wichtmann:
Effect of fines content on the undrained shear behaviour of sandy soils
An extensive experimental study of the undrained behaviour of sand- low plastic fines mixtures considering both the full range of fines contents from zero to 100% and from low to very high initial relative densities. The behaviour could be clearly distinguished between coarse-dominated and a fines-dominated region, where the threshold fines content was found to be about 32%. Based on the experimental data, a normalised critical state line function including the effect of fines content could be determined separately for the coarse-dominated and the fines-dominated region. However, the deduced relationship between the instability stress ratio and state parameter, the former indicating the stress condition at the onset of liquefaction, was very well defined for the coarse-dominated region, whereas larger deviations from the best fit line occurred in the fines-dominated region, indicating that other factors beside state parameter control the onset of liquefaction in low plastic fines.

3
Imre et al:
Comment on internal stability with rule and test results of Rahemi and Goudarzy
A series of 60 triaxial compression tests were conducted on Hostun sand - silt mixtures by Rahemi to investigate the effects of fines on the undrained monotonic response of sand. The results demonstrated that the transitionally stable mixtures with increasing fine content can increasingly be prone to liquefaction if all possible initial relative densities are considered. In a similar study, the boundary between the "fines-in-sand" and "sand-in-fines" micro-structure, the threshold fines content was found by Goudarzy at around A=2/3.
The grading entropy parameters are various statistical means. The base entropy S0 is a kind of dimensionless mean log diameter, which is similar to dm. Its normalized value the relative base entropy parameter A is a normalized mean log diameter, varying between 0 and 1 with a shift symmetry in the log diameter axis, the extremes are related to the minimum and maximum log diameters. A indicates the relative distance of the mean and the minimum log d value. It is a continuous internal stability measure, the A<2/3 condition indicates internally unstable soils.
The rule can be interpreted such that in Zone I (if A < 2/3) no structure of the large grains is present, the coarse particles “float” in the matrix of the fines and become destabilized when the fines are removed by piping. In the complementary zone (A = 2/3 and A > 2/3), it can be postulated that the coarse particles form a skeleton and total erosion cannot occur. In Zone III, the structure of larger particles is inherently stable.

4
James Leak, Daniel Barreto, Vasiliki Dimitriadi, Emőke Imre:
Fine content and liquefaction
The presence of fine particles is known to have significant effects on the mechanical response of soils. Specifically, the ability for fines to either increase of decrease a soils liquefaction susceptibility has been a topic of interest. Typical measures for liquefaction susceptibility in soils with fines content (Fc) typically rely on particle descriptors such as Cu or d50. This may be problematic as traditional particle descriptors do not recognize the effect of Fc on the occurrence of liquefaction. Grading entropy coordinates effectively ‘condense’ the whole of a particle size distribution (PSD) to a single point on a Cartesian plane, accounting for the information in the distribution. In this presentation, grading entropy coordinates are used to analyse 122 PSDs from Fc studies on liquefaction. It is suggested that increasing the Fc of a soil works to (overall) increase its liquefaction susceptibility by decreasing the soils internal stability and disrupting coarse grain particle contacts. Moreover, the normalised base entropy (A) has been shown to be related to the transmission of course-grain particle fabric and has been applied to the determination of the equivalent intergranular void ratio (e*). Hence, a modified equation for e* is also proposed.

5
Shuyin Feng:
Saturated permeability k in data bases
A comprehensive study on the hydraulic conductivity of different road construction materials. Three exceptionally large databases, each consists over a thousand hydraulic conductivity test data of different road construction materials, were presented. Calibrated transformation models based on the databases, which enable quick but reliable hydraulic conductivity predictions were then introduced. Statistical analysis on the transformation models validated the effectiveness of some less commonly used predictors for hydraulic conductivity such as the grading entropy and the water content ratio.

6
János Török:
Edwards Statistical Physics in granular matter
Theoretical Physics approach of Edwards is related to packing of spheres, 2+e dimensional frustrated granular system.

7
Min Wang:
Role of Gradation Curve in Description of Mechanical Behavior of Unsaturated Soils
The importance of soil water retention characteristics in modelling the hydro-mechanical response of unsaturated soils has been well recognised by many investigators in recent years. Determination of strain-dependent soil water retention curve (SWRC) is likely to be extraordinarily difficult. It is shown that SWRC can be computed from the gradation curve and the calculation result is consistent with the experimental results obtained from pressure plate tests.

8
Casini – Guida:
Evolution of grading curve sue to breakage and described by Weibull distribution
9
Daniel Barreto:
DEM study of Critical state using contact force entropy
A DEM study shows that Critical state can be defined using contact force entropy.

10
John McDougall:
The grading curves on the entropy diagram – a representation of salt dissolution and grading entropy diagram
Mass loss effect (indicated by parameter L) is introduced. The leaching salt out of a granular matter during an oedometer test  is examined in the grading entropy diagram where a coupling between particle loss and phase volume changes emerges. 
 The impact of salt loss on the sand skeleton:
  1. Small salt particles: nestle within the voids.  Removal of these particles has little impact on the remnant load bearing structure producing a near equivalent increase in void space.  A significant increase in void ratio with minimal settlement, L ≈ -1.0. 
  1. Large salt particles: related to the amount of particles in combination with force chains: 
    1. Small amounts of salt, few particles occupy force chains; dissolution occurs with little effect on the load-carrying capability. Settlement is minimal L → -1.0.
    2. Larger amounts of salt, particle size effects emerge. Particle rearrangement occurs due to buckling and collapse of strong force chains. Settlement is greatest and attains its highest value L → -0.45.
Experimental data presented show how both the amount and size of particles control overall volume and void ratio changes. Settlement is observed to be related primarily to the amount of particle loss and secondly to particle size.  Void ratio increase is related to particles loss but insensitive to particle size. 

11
Ákos Nemcsics:
Some aspects to the surfacial pattern and the volumetric granular distribution of the histrorical walling built from uncut stones
This written contribution is dealing with the investigation of walling structures in view point of pattern morphology and granular distribution. The investigated wallings are historical objects or built by historical technology. These walling were produced from uncut stones. On the surface, we observed periodicity and self-affine behaviour. In the granular distribution, power law was detected. The investigations were carried out party with on-site measurements and partly with the help of image processing.

 

 

Sessions:

Sept. 26. Dissipation type in situ tests (pdf files) (mp4 files)

Sept. 30. Special Soil - MSW Workshops (pdf files) (part1 mp4 files) (part2 mp4 files)

Oct. 1. Inverse Problem and Gravity and Grading Curve Workshop (pdf files) (mp4 files)

Date of formation: 15th of July, 2020.

 

Contact:
· 1081. Budapest, Népszínház u. 8.
· or 1034 Budapest, Doberdó út. 6.

E-mail:
· imre.emoke@uni-obuda.hu
· balint.agnes@uni-obuda.hu
· quynhuong1998@gmail.com
· iamjazz8343@gmail.com

 

Links:

 …software server link (itt lesznek a futtatható programok)