###### Evaluation of the Oedometer Tests of Municipal Landfill Waste Material

## Abstract

The aim of the ongoing research is (i) to develop a new biodegradation landfill technique so that the landfill gas production could be controlled and the utilisation of the landfill gas could economically be optimized, (ii) to plan the energy utilisation of the landfill including individual and combined solutions (solar, wind, geothermal energy, energy storage using methanol etc.). [1, 2, 3]

After summarizing the previous measurements made on the ongoing research, the first results of the oedometer tests are presented. The compression curves were determined, the measured data are evaluated by two simple models, the parameters are identified, the reliability of the parameters is tested.

The simple models make possible the separation of the three major components of the settlement: the immediate settlement, the creep settlement and the primary consolidation settlement. The degradation induced strains were not considered since the tests were short term. Using these components, three different oedometric moduli are defined.

The identified parameters are presented and compared with the parameters previously identified from some CPTu dissipation test data, and with the parameters measured by some recent seismic tests. The parameters are used to estimate the settlement of the landfill.

###### Relation Between Filtration and Soil Consolidation Theories

## Abstract

This paper presents a different, than commonly used, form of equations describing the filtration of a viscous compressible fluid through a porous medium in isothermal conditions. This mathematical model is compared with the liquid flow equations used in the theory of consolidation. It is shown that the current commonly used filtration model representation significantly differs from the filtration process representation in Biot’s and Terzaghi’s soil consolidation models, which has a bearing on the use of the methods of determining the filtration coefficient on the basis of oedometer test results. The present analysis of the filtration theory equations should help interpret effective parameters of the non-steady filtration model. Moreover, equations for the flow of a gas through a porous medium and an interpretation of the filtration model effective parameters in this case are presented.

###### Application of Genetic Algorithms for the Estimation of Hydraulic Conductivity

test. The pressures applied were: 12.5, 25, 50 and 100 kPa. Initial sample height h 0 = 20 mm and diameter d =75 mm was used. The results of the experiment are presented in Figure 5 . Figure 5 Oedometer test results. C V = K M γ w $$\begin{array}{} \displaystyle C_{V}=\frac{KM}{\gamma_{w}} \end{array}$$ (3) C V = 0.196 h 2 t 50 $$\begin{array}{} \displaystyle C_{V}=0.196\frac{h^2}{t_{50}} \end{array}$$ (4) C V = 0.848 h 2 t 90 $$\begin{array}{} \displaystyle C_{V}=0.848\frac{h^2}{t_{90}} \end{array}$$ (5) Based on the

###### On consistent nonlinear analysis of soil–structure interaction problems

′ $\begin{array}{} \displaystyle \sigma_{3}^{\prime} \end{array}$ stress dependency is used. The complete theory of the model, implemented in the ZSoil software, with all introduced modifications, can be found in the detailed report written by Obrzud and Truty [ 10 ]. It has to be emphasised here that most of the HS model parameters have clear physical interpretations, and model calibration can be made using standard triaxial consolidated drained (CD) or consolidated undrained (CU) test, including shear wave velocity measurement, and oedometer test. The latter one is

###### Treatment of a collapsible soil using a bentonite–cement mixture

of loading the soil progressively, starting from a known water content and an initial specific weight, up to 200 kPa, the stress at which the flooding of the sample is carried out. The axial deformation of the sample is measured by a dial gauge having an accuracy of the order of 1 mm. During flooding, the compaction of the specimen is recorded at different time intervals. 2.2.2 Shear tests Samples were prepared in the same manner as for oedometer tests samples and according to the French standard NF P 94-071-1. For each test, three normal stresses were used