scholarly journals Overconsolidation Ratio Determination of Cohesive Soil

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.

2018 ◽  
Vol 174 ◽  
pp. 01030
Author(s):  
Marta Kałuża ◽  
Jacek Hulimka ◽  
Jan Kubica ◽  
Kamil Kozdroń

In the last period, openwork facades have become very fashionable and commonly used in modern public buildings. They are characterised by an outstanding design and proper lighting of the interior spaces, while providing lightweight solution of the façade. The typical erecting method of an openwork façade - often made of ceramic components - is in-situ bricklaying using specific mortar dedicated to clinker elements. Unfortunately, ensuring proper executive conditions and preparation of the ceramic elements is not always possible. Hence, together with the development of architectural requirements, there has appeared a natural need to create prefabricated elements, which reflect the real bricklaying wall and ensure the safety of the solution. The paper presents a laboratory study on untypical application of a mortar for clinker, used to prefabrication of an elevation panel. The tests of mortar and solution of openwork prefabricated panel made using this mortar and special-shaped clinker components are presented and discussed. The material tests include determination of the strength properties of three types of mortar mixture, differing of each other by water content. The second part of this paper presents the laboratory tests of prefabricated panels, made using previously tested mortars, supported and loaded similar to the real working conditions.


2012 ◽  
Vol 16 (4) ◽  
pp. 1117-1126 ◽  
Author(s):  
Milos Banjac ◽  
Maja Todorovic ◽  
Milan Ristanovic ◽  
Radoslav Galic

Optimal design of a borehole heat exchanger, as the outer part of a ground source heat pump heating system, requires information on the thermal properties of the soil. Those data, the effective thermal conductivity of the soil ?eff and the average temperature of the soil T0, enable us to determine the necessary number and depth of boreholes. The determination of thermal conductivity of the soil in laboratory experiments does not usually coincide with the data under in-situ conditions. Therefore, an in-situ method of experimental determination of these parameters, the so-called thermal response test, is presented in this paper. In addition to the description of the experimental procedure and installation overview, the paper describes methods based on theory and presents their basic limitations, through the presentation of experimental data.


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):  
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.


1973 ◽  
Vol 10 (3) ◽  
pp. 397-409 ◽  
Author(s):  
Umesh Dayal ◽  
John H. Allen

The present paper describes the development of an instrumented impact cone penetrometer for a direct measurement of in situ strength properties of a soil target. The developed penetrometer, in addition to providing acceleration signatures (as obtained by previous investigators), is capable of recording cone thrust and local side friction simultaneously and continuously. The procedures have been outlined for estimating in situ strength properties and soil type of the target materials throughout the penetrated depth from the output records of these sensors. Typical test results generated from an on-going experimental program aimed at providing the data for (1) understanding the penetration mechanism, (2) development of penetration theory, and (3) designing the penetrometer for field tests, i.e. in situ testing of ocean floor soils, are also presented.


2018 ◽  
Vol 55 (4) ◽  
pp. 514-527
Author(s):  
Lang Liu ◽  
David Elwood ◽  
Derek Martin ◽  
Rick Chalaturnyk

A method was developed to interpret the horizontal permeability (kh) from pressuremeter pressure hold tests (PHTs) of approximately 3 min duration. The method relies on a regression analysis of the numerical analysis simulating the consolidation of clay under a constant pressure boundary during undrained expansion. The method was applied to a series of PHTs performed in deep clay formations in the Seattle area. The interpreted permeabilities are thought to be more representative of in situ conditions than those determined by laboratory testing by virtue of reduced disturbance during sample recovery and preparation. Results could be improved with a further exclusion of the creep effect on PHTs.


2017 ◽  
Vol 50 (2) ◽  
pp. 760
Author(s):  
A. Kokkala ◽  
V. Marinos

The design and construction of underground works in an urban environment, face several geological challenges. The construction of a well-structured database, able to store, manage, analyse and correlate a large amount of geological and geotechnical data, is a powerful tool towards the geological hazard assessment and the geotechnical characterisation of the formations along a tunnel. The data processed by the database are based on borehole geological information, laboratory testing, geotechnical characterisation and in situ field tests, mainly executed in the quaternary and neogene soil formations that are met along the studied area. The processing and assessment of the information, leads to the identification of useful value ranges for several physical and mechanical parameters. The study also focuses in specific areas within the basin of Thessaloniki, highlighting the in situ conditions, by the construction of longitudinal profiles. The purpose of that process, besides incorporating new data, is to provide a tool for turning data into useful information in order to estimate the geological situation and geotechnical behavior of formations in underground works.


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