scholarly journals The overconsolidation ratio of eemian gyttja determination

Author(s):  
Marek Bajda ◽  
Edyta E. Malinowska

Abstract The overconsolidation ratio of eemian gyttja determination. The overconsolidation ratio is an important parameter that determines the value of stress history exerted in the past on the subsoil in the geotechnical engineering. Overconsolidation ratio (OCR) is one of the main criteria conditioning soil behavior and characteristics. To know the relation between geological background, history and mechanical behavior of the soil, aims a knowledge that can help engineers who often have to predict soil behavior based upon the soil geological history and a geotechnical data. In order to evaluate the overconsolidation ratio of eemian gyttja, it is necessary to restore this soft soil as much as possible to the in situ conditions. The eemian gyttja is an organic soft soil from the “Zoliborz channel” located in Warsaw. These soils are used as a base construction in the foundation engineering. In practical geotechnical engineering, evaluation of stress history is based on the overconsolidation ratio. The overconsolidation ratio is one of the basic parameters for the geotechnical design of the structure. Determination of this parameter using for example dilatometer tests, is usually based on empirical formulas which were established in different countries. Therefore, regional geotechnical conditions could have substantially affected on the empirical relationships. The laboratory tests are used to determinate the preconsolidation pressure and then the overconsolidation ratio. The laboratory tests were made in the automatic oedometer and the in situ tests were carried out on the dilatometer test (DMT). The paper presents results of determination the overconsolidation ratio of eemian gyttja from the laboratory and in situ tests. The studies have shown that the values of the overconsolidation ratio determination from the laboratory tests are a little higher than determination from the in situ tests.

Author(s):  
Edyta E. Malinowska ◽  
Marek Bajda

Abstract The preconsolidation stress is an important phenomenon that determines the value of stress history exerted in the past on the subsoil in the geotechnical engineering. Overconsolidation ratio (OCR) is one of the main criteria conditioning soil behaviour and its characteristics. Here thought, the yield stress ratio (YSR) is used to determine the value of preconsolidation stress resulting from mechanical overburden than can be changed by many post depositional processes like secondary and tertiary compressibility, cementation, aging, temperature change and others. The yield stress ratio (YSR) is defined as the relationship between vertical yield stress (σ’vy) to the effective vertical stress (σ’v0). The eemian gyttja was used as a foundation in the engineering construction. In practical geotechnical engineering, evaluation of stress history is usually based on the overconsolidation ratio (OCR). The yield stress ratio (YSR) was used in the laboratory as one of the basic parameters for the geotechnical design of the structure. To know the relation between geological background, history and mechanical behaviour in long-time process of the soil aims a knowledge that can help engineers who often have to predict soil behaviour based upon the soil geological history and a few geotechnical data. In order to evaluate the yield stress ratio of eemian gyttja it is necessary to restore this soft, organic soil as much as possible to the in situ conditions. The laboratory tests were used to determinate the vertical yield stress and then the yield stress ratio. The laboratory tests were made in the automatic oedometer and the in situ tests were carried out on the dilatometer test (DMT). The comparison between the determination the yield stress ratio of eemian gyttja from the laboratory and the overconsolidation ratio from in situ test has been done. The studies have shown that the values of the overconsolidation ratio determinate from the laboratory tests are a little higher than determinate from the in situ tests.


1991 ◽  
Vol 28 (2) ◽  
pp. 210-225 ◽  
Author(s):  
M. F. Chang

The stress history as indicated by the profile of overconsolidation ratio (OCR) of a soil deposit is one of the most dominant factors that influence the engineering behaviour of the soil. Its assessment, which is traditionally based on the laboratory oedometer test, is not often satisfactory. The problem arises from inevitable sample disturbance and the high cost of a detailed investigation. These difficulties can be overcome by the use of in situ tests. The field vane test, the piezocone test, and the dilatometer test are three such methods that provide indirect means for the estimation of the OCR for clay deposits. A number of empirical correlations are available for this purpose. Calibration of these correlations against results of site investigation in Singapore and Malaysian marine clays reveals the usefulness of these test methods in profiling the OCR for Recent clay deposits. Key words: clay, in situ test, overconsolidation ratio, preconsolidation pressure, stress history.


2013 ◽  
Vol 12 (3) ◽  
pp. 097-104
Author(s):  
Maciej Kumor ◽  
Łukasz Kumor ◽  
Joanna Farmas

Geotechnical assessment of the implementation correctness of a road embankment wide range of issues, among which important selection and control of the quality of the earthworks are extremely significant. The article presents results of in situ tests determining correlations between the depending parameters defined by a static plate – VSS test – E1 and E2, and obtained from the study LFG Dynamic Load Plate. Studies indicate that the determination of the correlation between the parameters characterizing the particle size distribution (Cc, Cu, D10, D20, D30, D60), and the compaction parameters obtained by examining the compaction of sand embankment (Evd, E1, E2, I0) is physically complex and hence extremely difficult. 


Author(s):  
Donatas Urbaitis ◽  
Ieva Lekstutytė ◽  
Domas Gribulis

In order to evaluate overconsolidation ratio (OCR) of soil, the necessity to restore them as much as possible to in situ conditions appears, because sometimes when it is not taken into account, mistakes could be made while interpreting mechanical – strength properties of the soil. According to the work purpose, overconsolidation ratio of the investigated soil was set by performing odometer test and the obtained values were compared with the OCR calculated from cone and seismic penetration data. When the tests were performed and data analysed, it was found that OCR values depends on soil occurance depth, strength characteristics and stress conditions. The OCR values decreases with the declination of the depth. As many authors noted in the literature – the upper part of the soil is consolidated abnormally, thereby we can see that in our work. When results are evaluate, we can conclude that all of the analysed soils was overconsolidation. That was demonstrated by calculations according static penetration, oedometer test and seismic waves results. OCR values differences between the laboratory and field tests can show low quality of soil sampling, also due to correlations which was applied.


1993 ◽  
Vol 333 ◽  
Author(s):  
M. J. Plodinec ◽  
G. G. Wicks

ABSTRACTAn extremely important question for the eventual disposal of glass in natural environments is the relevance of laboratory testing of glass durability to the long-term performance of glass in geologic environments. The purpose of this study was to attempt to provide an empirical answer to that question, by applying the hydration thermodynamics approach (which has successfully been applied to laboratory tests of glass durability) to the results of longer-term testing in natural environments.The results show that hydration thermodynamics is a useful tool for explaining the effects of glass composition observed in in-situ tests, in several environments. Thus, it appears to provide a link between laboratory tests of glass durability and the results of in-situ tests in natural environments. Perhaps the most important conclusion of this effort is that the in-situ test results emphasize the importance of control of chemical composition during glass production as a means of achieving a durable glass.


2018 ◽  
Vol 64 (3) ◽  
pp. 67-80
Author(s):  
Piotr Radziszewski ◽  
Wioletta Jackiewicz-Rek ◽  
Michał Sarnowski ◽  
Marek Urbański

AbstractOver the course of operation, asphalt road pavements are subjected to damage from car traffic loads and environmental factors. One of the possible methods of strengthening damaged asphalt pavements may be the application of an additional rigid layer in the form of a cement concrete slab with continuous reinforcement.This paper presents a material-technological and structural solution for composite pavement where a cement concrete slab with continuous HFRP bar reinforcement is used for strengthening. Based on laboratory tests, the serviceability of composite bar reinforcement of rigid pavement slabs was shown. A design for strengthening asphalt pavement with a concrete slab with steel bar and corresponding HFRP bar reinforcement was developed. The composition of a pavement cement concrete mix was designed, and experimental sections were formed. Based on laboratory tests of samples collected from the surfaces of experimental sections and the diagnostic tests carried out in “in situ” conditions, the authors will try, in the nearest future (Part II: In situ observations and tests), to confirm the effectiveness of strengthening asphalt pavements with cement concrete slabs with HFRP components.


2006 ◽  
Vol 43 (2) ◽  
pp. 187-209 ◽  
Author(s):  
J Graham

Engineers in geotechnical practice work on increasingly complex problems with increasingly powerful numerical tools. Effective solutions to design problems need good information about the site and parameters (or functions) that describe how the soil will behave under the proposed loadings. These loadings can include heating, drying or wetting, time effects, and chemical changes as well as the more common structural loads. This paper outlines issues that need to be considered when laboratory tests are used to produce soil properties for use in numerical analyses. The focus is on soft to moderately stiff saturated clays. Similar considerations for in situ tests, stiff clays, and sands are not considered.Key words: clay, testing, characterization, properties, constitutive modeling.


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