scholarly journals Consolidation parameters in silts from varied rate CPTU tests

2021 ◽  
Vol 7 (4) ◽  
pp. 637-668
Author(s):  
Annika Bihs ◽  
◽  
Mike Long ◽  
Steinar Nordal ◽  
Priscilla Paniagua ◽  
...  
Keyword(s):  
Penetration Rate ◽  
Test Site ◽  
Laboratory Research ◽  
Design Parameters ◽  
Rate Dependency ◽  
Cone Penetration ◽  
Coefficient Of Consolidation ◽  
Cone Penetration Tests ◽  
Dissipation Test ◽  
Consolidation Parameters

<abstract> <p>The interpretation of dissipation tests from cone penetration tests (CPTU) in silt is often considered challenging due to the occurrence of an unknown degree of partial consolidation during penetration which may influence the results significantly. The main objective of the present study is to investigate the influence of penetration rate and hence partial consolidation in silt deposits on the interpretation of consolidation parameters. Rate dependency studies have been carried out so as to give recommendations on how to establish design consolidation parameters in silts and consider the effect of partial consolidation on the development of design parameters. A comprehensive field and laboratory research program has been conducted on a silt deposit in Halsen-Stj?rdal, Norway. Alongside performing various rate penetration CPTU tests with rates varying between 0.5 mm/s and 200 mm/s, dissipation tests were executed to analyze the consolidation behaviour of the soil deposit. Furthermore, a series of soil samples have been taken at the site to carry out high quality laboratory tests. Correction methods developed for non-standard dissipation tests could be successfully applied to the silt deposit indicating partial consolidation. The results revealed an underestimation of the coefficient of consolidation if partial consolidation is neglected in the analysis, emphasizing the importance of considering the drainage conditions at a silt site thoroughly. To study the drainage conditions of a soil deposit a recently proposed approach has been applied introducing a normalized penetration rate to differentiate between drained and undrained behaviour during penetration. It is suggested that a normalized penetration rate of less than 0.1–0.2 indicate drained behaviour while a normalized penetration rate above 40–50 indicate undrained behaviour. Finally, available dissipation test data from a Norwegian Geo-Test Site (NGTS) in Halden, Norway have been used to successfully verify the recommendations made for silts.</p> </abstract>

Evaluation of correlation between parameters from CPTU and DMT tests and soil type behavior chart

2018 ◽  
Vol 50 (4) ◽  
pp. 313-326
Author(s):  
Simon Rabarijoely
Keyword(s):  
Test Site ◽  
Soil Parameters ◽  
Soil Behavior ◽  
Cone Penetration ◽  
Behavior Type ◽  
Cone Penetration Tests ◽  
Classification Index ◽  
Penetration Tests ◽  
The Relationship ◽  
Type Classification

Abstract This paper presents the correlation of soil parameters obtained from the dilatometer of the Marchetti (DMT) and the cone penetration tests (CPT). The data for the development of these correlations come from four experimental sites of the Department of Geotechnical Engineering of the Warsaw University of Life Sciences – SGGW: test embankment in Antoniny, and the Koszyce and Nielisz water dams, Stegna test site, WULS-SGGW Campus. Additionally, the relationship between the soil behavior type classification index (Ic) from the Cone Penetration Test (CPT) and the material index (I D) from the dilatometer test (DMT) based on the Robertson method, modified in this paper, is presented. Finally, a new soil behavior type classification chart was presented, allowing to determine not only the type and condition of the soil, but also the stress history (OCR).

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.

In situ characterization of land reclaimed using big clay lumps

2004 ◽  
Vol 41 (2) ◽  
pp. 242-256 ◽  
Author(s):  
Muthusamy Karthikeyan ◽  
Ganeswara Rao Dasari ◽  
Thiam-Soon Tan
Keyword(s):  
Land Reclamation ◽  
Site Investigation ◽  
Test Site ◽  
Engineering Properties ◽  
Cone Penetration ◽  
In Situ Characterization ◽  
Ultimate State ◽  
Reclaimed Land ◽  
Cone Penetration Tests

Dredging works in the sea and excavations in built-up areas produce large quantities of clay lumps in Singapore. The use of these clay lumps for land reclamation is an attractive proposition for solving the problem of finding dumping grounds for disposal and at the same time creating new land. When these big clay lumps are used for reclamation, however, the land will have large initial interlump voids. These large interlump voids may not close completely, even with surcharge, and may lead to excessive settlement when a structure is constructed on land reclaimed using this material. Two major engineering issues related to the use of clay lumps for reclamation are the size of interlump voids at the end of consolidation and the engineering properties of such ground. The need to know the ultimate state of the ground reclaimed using large clay lumps is critical to its acceptance as a viable fill material. To our knowledge, data on the ultimate state of such reclaimed lands are not available. An extensive site investigation was performed at a test site on the island of Punggol Timor in Singapore, which was reclaimed about 12 years ago using big dredged clay lumps. The thrust of the investigation is to evaluate the present state of the reclaimed land, with special emphasis on identifying the size of current interlump voids. The radioisotope cone penetration test was employed to measure the in situ density of the site. The site investigation also included high-quality soil sampling and laboratory testing to determine the present strength and deformation characteristics of the reclaimed land. The results indicate that the initially large interlump voids have been reduced to the size of intralump voids. However, the layer formed from clay lumps is heterogeneous and exhibits variable engineering properties. Key words: in situ characterization, land reclamation, radioisotope cone penetration tests, wet density, big clay lumps.

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.

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