Use and interpretation of a research dilatometer

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.'

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Development of a New Testing Approach for Decentralised Technical Sustainable Drainage Systems

Water ◽

10.3390/w13050722 ◽

2021 ◽

Vol 13 (5) ◽

pp. 722

Author(s):

Johannes Wolfgang Neupert ◽

Philipp Lau ◽

Daniel Venghaus ◽

Matthias Barjenbruch

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Test Procedure ◽

Test Stand ◽

Test Substance ◽

Test Procedures ◽

Drainage Systems ◽

Sustainable Drainage Systems

A part of the sustainable drainage systems (SuDS) are used to treat stormwater and must be tested for their hydraulic performance and the removal efficiency to assess serviceability and retention of the pollutants efficacy for in situ use. Current test procedures provide a good basis for laboratory testing SuDS on the test stand. However, the evaluation is not sufficiently representative to compare different SuDS with each other or for in situ use. The individual steps and specifications of an applied test procedure in Germany were considered and evaluation and optimizations for the test substance and sampling methodology of SuDS on the test stand were proposed. A comparison of the particle size distribution of the test substance Millisil W4 currently in use and total suspended solids of real road runoff was made, which showed that the presented test substance of real road-deposited sediments (RDS) provides a better reference for the test conditions and they could be the basis for more representative test methods. A particle size distribution was proposed for this new test substance. Furthermore, two methods of sampling were compared, which showed that a full flow sampling is preferable to a discrete sample. At the same time, it was shown that a separation limit of 20 µm is sufficient for the determination of TSS63.

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Standard penetration test energy measurements using a system based on the personal computer

Canadian Geotechnical Journal ◽

10.1139/t92-062 ◽

1992 ◽

Vol 29 (4) ◽

pp. 551-557 ◽

Cited By ~ 12

Author(s):

Peter K. Robertson ◽

David J. Woeller ◽

Kofi O. Addo

Keyword(s):

Energy Transfer ◽

Test Procedure ◽

Standard Penetration Test ◽

Energy Calibration ◽

Calibration System ◽

Penetration Test ◽

Reference Test ◽

Time Record ◽

Force Time

According to the International Reference Test procedure for the standard penetration test (SPT), in situations where comparisons of SPT results are important, calibrations should be made to evaluate the efficiency of the equipment in terms of energy transfer. However, equipment to measure the energy transfer of the hammer anvil system is not commonly available. Ten years ago a system was developed and made commercially available. However, this system is no longer available. An SPT energy calibration system is described that has been developed based on a microcomputer. The load cell to measure the compressive stress wave beneath the SPT anvil consists of a 0.5-m length of strain-gauged AW rod. Specialized software has been developed to record the force–time record for each hammer blow on a portable microcomputer. Examples of energy measurements are presented and discussed. Key words : standard penetration test, in situ, microcomputer, energy.

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Piezometer–friction cone investigation at a tailings dam

Canadian Geotechnical Journal ◽

10.1139/t84-057 ◽

1984 ◽

Vol 21 (3) ◽

pp. 551-562 ◽

Cited By ~ 9

Author(s):

R. G. Campanella ◽

P. K. Robertson ◽

D. Gillespie ◽

E. J. Klohn

Keyword(s):

British Columbia ◽

Relative Density ◽

Pore Water ◽

Pore Water Pressure ◽

Water Pressure ◽

Tailings Dam ◽

Pressure Gradients ◽

University Of British Columbia ◽

Bearing Friction

Static piezometer–friction cone tests were carried out at the tailings dam at Brenda Mines, Peachland, British Columbia to evaluate soil characteristics and seepage conditions in the dam. Several types of electric quasistatic cones were pushed to depths of 40–70 m at various locations in the dam and on the beach. The cones used included both the Fugro electric friction cone and piezometer cone, and a University of British Columbia designed piezometer–friction cone.Site conditions are described and typical cone logs of bearing, friction, friction ratio, and pore water pressure vs. depth are presented, interpreted, and discussed. The cone data is used to assess strength and relative density, and to assess gradational variations of the tailings and slimes on the beach, including the identification of ice inclusions.Measurements of equilibrium pore water pressures with depth at three locations on the beach allowed a clear picture to be developed of the pore pressure gradients within the dam. Other problems and experiences concerning quasistatic cone logging for a tailings dam are also discussed. Key words: in situ testing, static penetration testing, piezometer cone, tailings dam, tailings beach, seepage, strength, relative density, ice, pore pressures.

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Reliability of Piezocone Penetration Test Methods for Estimating the Coefficient of Consolidation of Cohesive Soils

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198105191300107 ◽

2005 ◽

Vol 1913 (1) ◽

pp. 62-76 ◽

Cited By ~ 2

Author(s):

Murad Y. Abu-Farsakh ◽

Munir D. Nazzal

Keyword(s):

Test Methods ◽

Cohesive Soils ◽

Penetration Test ◽

Coefficient Of Consolidation ◽

Piezocone Penetration Test ◽

Cone Tip Resistance ◽

Tip Resistance ◽

Penetration Depths ◽

Better Than

The current piezocone penetration test (PCPT) interpretation methods were evaluated for their capability to estimate the vertical coefficient of consolidation (c v) of cohesive soils reasonably by using the piezocone dissipation tests. Seven PCPT methods were evaluated. Six sites in Louisiana were selected for this study. At each site, in situ PCPT tests were performed, and soundings of cone tip resistance, sleeve friction, and pore pressures at different locations were recorded. Piezocone dissipation tests also were conducted at different penetration depths. High-quality Shelby tube samples were collected close to the PCPT tests and were used to carry out a comprehensive laboratory testing program. The (c v) values predicted by the different interpretation methods were compared with the reference values determined from the oedometer laboratory tests. The results of this study showed that two methods can estimate cv better than the other prediction methods.

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Reliability of Laboratory Tests for the Control of Oral Anticoagulation

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647716 ◽

1974 ◽

Vol 32 (02/03) ◽

pp. 483-491

Author(s):

E. A Loeliger ◽

M. J Boekhout-Mussert ◽

L. P van Halem-Visser ◽

J. D. E Habbema ◽

H de Jonge

Keyword(s):

Human Brain ◽

Laboratory Tests ◽

Test Procedure ◽

Rabbit Brain ◽

Normal Range ◽

Test Procedures ◽

Discrimination Power ◽

Power Of The Test ◽

Assay Procedure ◽

Low Sensitivity

SummaryThe present study concerned the reproducibility of the so-called prothrombin time as assessed with a series of more commonly used modifications of the Quick’s onestage assay procedure, i.e. the British comparative reagent, homemade human brain thromboplastin, Simplastin, Simplastin A, and Thrombotest. All five procedures were tested manually on pooled lyophilized normal and patients’ plasmas. In addition, Simplastin A and Thrombotest were investigated semiautomatically on individual freshly prepared patients’ plasmas. From the results obtained, the following conclusions may be drawn :The reproducibility of results obtained with manual reading on lyophilized plasmas is satisfactory for all five test procedures. For Simplastin, the reproducibility of values in the range of insufficient anticoagulation is relatively low due to the low discrimination power of the test procedure in the near-normal range (so-called low sensitivity of rabbit brain thromboplastins). The reproducibility of Thrombotest excels as a consequence of its particularly easily discerned coagulation endpoint.The reproducibility of Thrombotest, when tested on freshly prepared plasmas using Schnitger’s semiautomatic coagulometer (a fibrinometer-liJce apparatus), is no longer superior to that of Simplastin A.The constant of proportionality between the coagulation times formed with Simplastin A and Thrombotest was estimated at 0.64.Reconstituted Thrombotest is stable for 24 hours when stored at 4° C, whereas reconstituted Simplastin A is not.The Simplastin A method and Thrombotest seem to be equally sensitive to “activation” of blood coagulation upon storage.

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