Effect Rate of Strain on In Situ Horizontal Coefficient of Consolidation from Pressuremeter

2019 ◽  
Vol 38 (2) ◽  
pp. 1669-1674 ◽  
Author(s):  
Radhi Alzubaidi
Keyword(s):  
Coefficient Of Consolidation ◽  
Effect Rate

In situ estimation of the coefficient of consolidation in clays

1990 ◽  
Vol 27 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Mohammed G. Kabir ◽  
Alan J. Lutenegger
Keyword(s):  
Key Words ◽  
Pore Pressure ◽  
Reference Values ◽  
Time Factors ◽  
In Situ Tests ◽  
Coefficient Of Consolidation ◽  
Oedometer Test ◽  
Undisturbed Samples ◽  
Oedometer Tests

An investigation was conducted to demonstrate the applicability of cylindrical piezocone and flat piezoblade tests for providing reliable estimates of the coefficient of consolidation in clays. Coefficients of consolidation were calculated from piezocone dissipation tests for different degrees of consolidation using theoretical time factors to provide a comparison with laboratory oedometer tests. Three techniques were developed to calculate the coefficient of consolidation from piezoblade dissipation tests. Results from in situ pore pressure dissipation tests were compared with laboratory oedometer tests performed on undisturbed samples oriented in both the vertical and horizontal directions, to provide reference values of cv and ch. The results of investigations conducted at several clay sites are presented. Key words: in situ tests, piezocone, piezoblade, coefficient of consolidation, oedometer test, clays.

Test fill on soft plastic marine clay at Onsøy, Norway

2014 ◽  
Vol 51 (1) ◽  
pp. 30-50 ◽  
Author(s):  
Toralv Berre
Keyword(s):  
Soft Clay ◽  
Marine Clay ◽  
Coefficient Of Consolidation ◽  
Geotechnical Parameters ◽  
Second Stage ◽  
Direct Simple Shear ◽  
Rapid Construction ◽  
Loading Case ◽  
The Town

The test fill at Onsøy, close to the town of Fredrikstad in Norway, was built on a very soft marine clay with in situ vane strength as low as 11 kPa and a plasticity index varying from 34 to 50. The dimensions at the bottom of the long fill were 20 m × 60 m and the height 2.3 m. The fill, as placed, had a computed factor of safety against foundation failure of 1.35 based on in situ vane strength. The fill was allowed to sit for about 3 years (from 1972 to 1975) before it, in a second stage, was brought to failure by raising the height. The main purpose of the first stage was to study the stress–strain–time relationships for the soft clay and compare the values of geotechnical parameters determined by careful laboratory tests with those back-calculated from the observed field behaviour. The test fill foundation was heavily instrumented to measure clay deformations and pore pressures with time. Field observations showed that the Onsøy test fill turned out to be more of a drained loading case than an undrained case in spite of the fairly rapid construction of the fill. Actually, subsequent undrained triaxial and direct simple shear tests strongly indicate that the fill might have failed if less drainage had taken place, i.e., if the drainage paths had been longer and (or) if the coefficient of consolidation had been lower.

Effect of sample size on consolidation of a fissured clay

1988 ◽  
Vol 25 (1) ◽  
pp. 76-84 ◽  
Author(s):  
Vinod K. Garga
Keyword(s):  
Experimental Investigation ◽  
Size Effect ◽  
Sample Size ◽  
Coefficient Of Consolidation ◽  
Different Depths ◽  
In Situ Permeability ◽  
London Clay ◽  
Constant Head ◽  
Oedometer Tests

This paper describes an experimental investigation on the effect of sample size on consolidation characteristics of fissured London Clay. Pore pressure dissipation tests on 38, 100, and 300 mm diameter samples were undertaken in the laboratory. Constant-head in situ permeability tests were conducted in four boreholes at different depths in the clay. Conventional oedometer tests on 76 mm diameter samples recovered from the same depths at which in situ permeability tests were carried out were also undertaken. The results show that both the coefficient of compressibility mv and the coefficient of consolidation determined in the laboratory are not significantly affected by sample size. It is concluded that estimate of in situ coefficient of consolidation can best be made from mv determined in the laboratory, and from in situ permeability measurements. Key words: consolidation, compressibility, fissured clay, permeability, size effect, testing.

scholarly journals A New Method for the Estimation of Hydraulic Permeability, Coefficient of Consolidation, and Soil Fraction Based on the Dilatometer Tests (DMT)

2019 ◽  
Vol 41 (4) ◽  
pp. 212-222 ◽  
Author(s):  
Simon Rabarijoely
Keyword(s):  
Permeability Coefficient ◽  
Clay Soil ◽  
Life Sciences ◽  
Hydraulic Permeability ◽  
Coefficient Of Consolidation ◽  
Soil Fraction ◽  
Overburden Stress ◽  
Flat Dilatometer Test

AbstractThe main issue of the paper is the estimation of soil hydraulic permeability based on the DMT test. DMTA, DMTC and SASK methods performed in the Nielisz dam, Stegny and the SGGW Campus of the Warsaw University of Life Sciences sites are described. The article presents the implementation of the dilatometer Marchetti test (DMT) in the determination of soil fraction and effects of its occurrence in the subsoil, tested in the Nielisz dam located in the Wieprz river valley in the Lublin province, and in various sites in Warsaw (Stegny site and SGGW Campus of the Warsaw University of Life Sciences). In order to acquire the needed data, the flat dilatometer test (DMT) method was used. A direct and indirect pressure methodology of interpreting soil swelling was characterized in the article. The paper shows the possibilities of determining sand, silt and clay soil fractions based on po and p1 pressures from dilatometer tests (DMT) and the effective (σ’vo) and total (σvo) vertical in situ overburden stress. Additionally, the main advantage of this paper is the proposal of use of a new chart to determine hydraulic permeability and soil fraction, based on DMT tests.

Use and interpretation of a research dilatometer

1991 ◽  
Vol 28 (1) ◽  
pp. 113-126 ◽  
Author(s):  
R. G. Campanella ◽  
P. K. Robertson
Keyword(s):  
British Columbia ◽  
Test Procedure ◽  
Earth Pressure ◽  
Penetration Test ◽  
Test Procedures ◽  
Coefficient Of Consolidation ◽  
University Of British Columbia ◽  
Constrained Modulus ◽  
Passive Measurements

The flat dilatometer (DMT) test was introduced by Marchetti (1980) as a new in situ penetration test for soils. The equipment and test procedures are simple, and the test provides repeatable, nearly continuous data that has been empirically correlated to soil type, undrained shear strength (su), coefficient of earth pressure at rest (K0), overconsolidation ratio (OCR), and constrained modulus (M). To better understand the measurements from the DMT, a research flat dilatometer was developed at the University of British Columbia (UBC). The research dilatometer is identical in size, shape, and operation to the Marchetti blade except that instrumentation was added which made passive measurements of pore pressure and deflection at the centre of the membrane, inflation pressure at the membrane, verticality of the blade, and penetration force immediately above the blade. Results from several well-documented sites near Vancouver, British Columbia, using the research DMT are presented and discussed. Results from the research DMT have provided useful insight into the test procedure and interpretation methods of the standard Marchetti DMT. Stress-deflection curves for the DMT are remarkably similar to both self-bored and full displacement pressuremeter test results. Alternate DMT procedures are proposed to estimate ø′ of sands and coefficient of consolidation in clays. A procedure incorporating the closing pressure (P2) using a standard Marchetti DMT is proposed and evaluated. Key words: flat dilatometer test, in situ, research, cone penetration test, pore pressures.'

A geotechnical investigation of marine deposits in a nearshore seabed for land reclamation

1999 ◽  
Vol 36 (6) ◽  
pp. 981-1000 ◽  
Author(s):  
Kin-Man Lee ◽  
Patrick CC Ng
Keyword(s):  
Land Reclamation ◽  
Large Diameter ◽  
Field Tests ◽  
In Situ Tests ◽  
Coefficient Of Consolidation ◽  
Marine Deposits ◽  
Undisturbed Samples ◽  
Horizontal Drainage ◽  
Rowe Cell

The properties of marine deposits in a nearshore seabed at a land reclamation site in Hong Kong were investigated. A variety of laboratory and in situ tests were conducted to define the geotechnical and consolidation characteristics of the marine deposits. The reliability and applicability of various laboratory and in situ testing techniques in evaluating the coefficient of consolidation were examined. Coefficients of consolidation were calculated from conventional oedometer tests, large-diameter (250 mm) Rowe cell tests, field permeability tests, and piezocone dissipation tests. Three techniques were adopted to evaluate the horizontal coefficient of consolidation ch from the results of in situ piezocone dissipation tests. Results from in situ pore pressure dissipation tests are compared with those from large-diameter Rowe cell tests performed on undisturbed samples under both vertical and horizontal drainage conditions and in situ permeability tests to provide reference values of the vertical coefficient of consolidation cv and ch. The engineering implications, particularly those related to land reclamation work in the nearshore environment, of various laboratory and field tests are discussed.

Estimating coefficient of consolidation from piezocone tests

1992 ◽  
Vol 29 (4) ◽  
pp. 539-550 ◽  
Author(s):  
P. K. Robertson ◽  
J. P. Sully ◽  
D. J. Woeller ◽  
T. Lunne ◽  
J. J. M. Powell ◽  
...  
Keyword(s):  
Pore Pressure ◽  
Published Data ◽  
Pressure Data ◽  
Cone Penetration ◽  
Coefficient Of Consolidation ◽  
New Correlation ◽  
Coefficient Of Permeability ◽  
North And South America ◽  
North And South

Data have been reviewed from sites in Europe and North and South America as well as published data from South Africa. The review has concentrated on dissipation data from piezocone tests (CPTU) to compare predicted coefficient of consolidation and permeability values using published interpretation techniques with available reference values. The results of this review have shown that the theoretical solutions provide reasonable estimates of the in situ coefficient of consolidation. Results were evaluated for pore-pressure data from different locations on the piezocone, and the least scatter in results was obtained with the pore-pressure element location immediately above the cone tip. A new correlation has been proposed to estimate in situ horizontal coefficient of permeability (kh) from piezocone dissipation data. Key words : in situ, coefficient consolidation, cone penetration test, permeability.

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