Rate-controlled cone penetration tests in permafrost

2005 ◽  
Vol 42 (1) ◽  
pp. 184-197 ◽  
Author(s):  
Sylvie Buteau ◽  
Richard Fortier ◽  
Michel Allard
Keyword(s):  
Active Layer ◽  
Penetration Rate ◽  
Load Capacity ◽  
Creep Behaviour ◽  
Homogeneous Layer ◽  
Cone Penetration ◽  
Creep Tests ◽  
Cone Penetration Tests ◽  
Rate Controlled ◽  
Penetration Tests

Cone penetration tests (CPTs) were carried out in the summers of 1999 and 2000 in a permafrost mound near Umiujaq, in northern Quebec, Canada, to study the cryostratigraphy and assess the creep behaviour of permafrost. A new linear pushing system using an actuator technology was specifically designed and developed to accurately control the penetration rate of the cone in the permafrost. This system has a load capacity of about 113 kN at a maximum penetration rate of 1.5875 cm/s and a stroke of 120 cm and can provide constant penetration rates as low as 4 × 10–6 cm/s. It can be disassembled in pieces for easy hand transport and use in remote locations. Two different types of CPT were performed in the permafrost mound: stratigraphic profiling and creep test. The first type is a quasi-static CPT at a penetration rate of 0.1 cm/s, providing a stratigraphic profile of permafrost in terms of the measurement of penetrometer sensors as a function of depth. The second type is a series of quasi-static CPTs at incremental rates of penetration, from 10–4 to 10–2 cm/s, carried out in a homogeneous layer to study the creep behaviour of permafrost. Five distinct zones (unfrozen and frozen active layer, permafrost, cryotic but unfrozen ground, and perennially noncryotic ground) can be identified in the stratigraphic profiles. The creep exponents calculated from the creep tests range from 12 to 35 for the ice-poor frozen active layer and from 4 to 11 for the ice-rich permafrost. Key words: cone penetration test, permafrost, rate-controlled, creep behaviour, cryostratigraphy.

Prediction of pile shaft resistance using cone penetration tests (CPTs)

2012 ◽  
Vol 45 ◽  
pp. 74-82 ◽  
Author(s):  
Mohammad Hassan Baziar ◽  
Armin Kashkooli ◽  
Alireza Saeedi-Azizkandi
Keyword(s):  
Cone Penetration ◽  
Shaft Resistance ◽  
Pile Shaft ◽  
Cone Penetration Tests ◽  
Penetration Tests

scholarly journals Using CPTs to derive thermal properties of soil

2020 ◽  
Vol 205 ◽  
pp. 04005
Author(s):  
Philip J. Vardon ◽  
Joek Peuchen
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Laboratory Tests ◽  
Field Investigation ◽  
Volumetric Heat Capacity ◽  
Cone Penetration ◽  
Cone Penetration Tests ◽  
Penetration Tests ◽  
Properties Of Soil

A method of utilizing cone penetration tests (CPTs) is presented which gives continuous profiles of both the in situ thermal conductivity and volumetric heat capacity, along with the in situ temperature, for the upper tens of meters of the ground. Correlations from standard CPT results (cone resistance, sleeve friction and pore pressure) are utilized for both thermal conductivity and volumetric heat capacity for saturated soil. These, in conjunction with point-wise thermal conductivity and in situ temperature results using a Thermal CPT (T-CPT), allow accurate continuous profiles to be derived. The CPT-based method is shown via a field investigation supported by laboratory tests to give accurate and robust results.

scholarly journals The architecture of the Kattendijk Formation and the implications on the early Pliocene depositional evolution of the southern margin of the North Sea Basin

2020 ◽  
Vol 23 (3-4) ◽  
Author(s):  
Jef DECKERS ◽  
Stephen LOUWYE
Keyword(s):  
Cone Penetration ◽  
Early Pliocene ◽  
Cone Penetration Tests ◽  
The North ◽  
Lower Oligocene ◽  
Deep Incision ◽  
The North Sea ◽  
Depositional Evolution ◽  
Penetration Tests ◽  
East West

An east-west correlation profile through the upper Neogene succession north of Antwerp, based on cone penetration tests, reveals the architecture of the lower Pliocene Kattendijk Formation. It shows a basal incision of the Kattendijk Formation down to 20 m in Miocene sands and locally even Lower Oligocene clays. The incision is part of a much larger gully system in the region at the base of the Kattendijk Formation. The strongest gully incision is observed along the western profile, and coincides with increases in the thickness of the Kattendijk Formation from its typical four to six meters thickness in the east towards a maximum of 15 m in the west. Correlations show that this additional thickness represents a separate sequence of the Kattendijk Formation that first filled the deepest part of the gully prior to being transgressed and covered by the second sequence deposited in a larger gully system. Both sequences of the Kattendijk Formation have basal transgressive layers, and are lithologically identical. Initial, deep incision at the base of the Kattendijk Formation might have been the result of the constriction of early Pliocene tidal currents that invaded and expanded fluvial or estuarine gullies that had developed during the latest Miocene sea-level low. A similar mechanism had been proposed for the development of late Miocene gully system at the base of the Diest Formation further southeast in northern Belgium. As the wider area was transgressed and covered by the second sequence of the Kattendijk Formation, flow constriction ended, currents weakened and gully incisions were reduced in size.

Comparison of Measured and Back Estimated Cone Penetration Resistance of Sand

2008 ◽  
Author(s):  
Meen-Wah Gui ◽  
Dong-Sheng Jeng
Keyword(s):  
Penetration Resistance ◽  
Cavity Expansion ◽  
Cone Penetration ◽  
Cone Penetration Tests ◽  
Cone Tip Resistance ◽  
Tip Resistance ◽  
Cone Penetration Resistance ◽  
Expansion Theory ◽  
Cavity Expansion Theory ◽  
Penetration Tests

The application of cavity expansion theory in the back estimation of cone penetration tests conducted in calibration chambers has been carried out by many researchers. However, the theory is seldom employed by centrifuge modelers. Based on the work of spherical cavity expansion of previous researchers, this study proposed an analytical solution that incorporates the effects of cone geometry and surface roughness and the effect of compressibility to estimate the cone tip resistance. The calculated results are compared with the measured cone penetration resistance of four cone penetration tests performed in the centrifuge. The cone penetration tests were conducted in granular soil specimens having relative densities ranging between 54% and 89%. The comparison demonstrates the capacity of the cavity expansion theory in the prediction of the centrifuge cone penetration resistance.

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