Vibratory compaction of coarse-grained soils

2002 ◽  
Vol 39 (3) ◽  
pp. 695-709 ◽  
Author(s):  
K Rainer Massarsch ◽  
Bengt H Fellenius
Keyword(s):  
Effective Stress ◽  
Soil Compaction ◽  
Earth Pressure ◽  
Coarse Grained ◽  
Cone Penetration ◽  
Cone Penetration Tests ◽  
The Earth ◽  
Vibratory Compaction ◽  
Friction Measurements ◽  
Penetration Tests

The variation of the coefficient of earth pressure in normally consolidated and overconsolidated soil and the effect of soil compaction on the change of the horizontal effective stress are discussed based on cone penetration test (CPT) data. A method is outlined for estimating the increase in the effective earth pressure based on sleeve friction measurements. Soil compaction increases not only soil density, but also horizontal effective stress. Since the cone stress is influenced by the vertical and horizontal effective stress, particularly at shallow depths, the cone stress needs to be adjusted for effective mean stress. A relation is presented for determining the soil compressibility from the adjusted cone stress. A case history is presented where a 10 m thick sand fill was compacted using vibratory compaction. Cone penetration tests indicated a significant increase in cone stress and sleeve friction and a decrease in compressibility (increase in modulus number) due to compaction. The friction ratio was unchanged. It was concluded that the earth pressure about doubled corresponding to an increase in the overconsolidation ratio of at least 5. The results of settlement calculations based on the Janbu method demonstrate the importance of considering the preconsolidation effect in the analyses.Key words: sand, CPTU, vibratory compaction, earth pressure, overconsolidation, modulus number, settlement.

scholarly journals Coupled DEM-FDM simulation of cone penetration tests in coarse grained soils

2021 ◽  
Vol 249 ◽  
pp. 11012
Author(s):  
Mussie Kidane ◽  
Andrés Alfonso Peña Olarte ◽  
Roberto Cudmani
Keyword(s):  
Distinct Element ◽  
Particle Interaction ◽  
Constitutive Models ◽  
Coarse Grained ◽  
Cone Penetration ◽  
Promising Alternative ◽  
Cone Penetration Tests ◽  
Penetration Tests ◽  
Number Of Particles ◽  
Element Method

The numerical modelling of geotechnical problems often poses major challenges when large displacements and strain localization are involved. Conventional continuum mechanical approaches like the finite element method (FEM) or the finite difference method (FDM) suffer from mesh distortion and numerical inaccuracy when large deformations are involved. In addition, they require the use of appropriate constitutive models to simulate the soil behaviour. The distinct element method is a promising alternative for large deformation analyses. It does not have the limitations resulting from the numerical discretization of the continuumand not need a constitutive model since the macroscopic response results from the individual particle interaction. However, the maximum number of particles and therefore the domain of the simulation is nowadays limited by the available computational capacity. To overcome this limitation, a coupled DEM-FDM approach is proposed used to optimize the number of particles for a combined numerical domain consisting of areas of large and small displacements. The performance of the coupled DEM-FDM approach is investigated by simulating cone penetration tests in coarse grained soils.

Cone penetration tests in unsaturated silty sands

2016 ◽  
Vol 53 (3) ◽  
pp. 431-444 ◽  
Author(s):  
Hongwei Yang ◽  
Adrian R. Russell
Keyword(s):  
Effective Stress ◽  
Unsaturated Soils ◽  
Penetration Resistance ◽  
Silty Sand ◽  
Cone Penetration ◽  
Confining Stress ◽  
Cone Penetration Tests ◽  
Hydraulic Hysteresis ◽  
Cone Penetration Resistance ◽  
Penetration Tests

Very little is known about how to interpret cone penetration tests (CPTs) when performed in unsaturated soils. The few published studies on CPTs in unsaturated soils have focused on either clean sands or silt. In this study, new results of laboratory-controlled CPTs in an unsaturated silty sand are presented. Silty sand exhibits hydraulic hysteresis and suction hardening. Suction is observed to have a pronounced effect on measured cone penetration resistance. For an isotropic net confining stress of 60 kPa, it is observed that higher suctions give rise to cone penetration resistances that are 50% larger than those for lower suctions. A semi-theoretical correlation is presented that links measured cone penetration resistances to initial relative density and mean effective stress. Suction has an influence on cone penetration resistances through suction hardening, as well as its contribution to effective stress. For this silty sand, it is shown that failing to account for suction may result in significant overestimations and unsafe predictions of soil properties from measured cone penetration resistances.

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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