Reply to the discussion by Mesri and Wang on “Correlations for undrained shear strength of Finnish soft clays”

2017 ◽  
Vol 54 (5) ◽  
pp. 749-753 ◽  
Author(s):  
Marco D’Ignazio ◽  
Kok-Kwang Phoon ◽  
Siew Ann Tan ◽  
Tim Länsivaara ◽  
Suzanne Lacasse
Keyword(s):  
Shear Strength ◽  
Undrained Shear Strength ◽  
Soft Clays ◽  
Undrained Shear

scholarly journals A Random Forest Model for the Prediction of Spudcan Penetration Resistance in Stiff-Over-Soft Clays

2020 ◽  
Vol 27 (4) ◽  
pp. 130-138
Author(s):  
Pan Gao ◽  
Zhihui Liu ◽  
Ji Zeng ◽  
Yiting Zhan ◽  
Fei Wang
Keyword(s):  
Shear Strength ◽  
Random Forest ◽  
Penetration Resistance ◽  
Undrained Shear Strength ◽  
Soil Parameters ◽  
Good Prediction ◽  
Resistance Profile ◽  
Soft Clays ◽  
Centrifuge Tests ◽  
Undrained Shear

AbstractPunch-through is a major threat to the jack-up unit, especially at well sites with layered stiff-over-soft clays. A model is proposed to predict the spudcan penetration resistance in stiff-over-soft clays, based on the random forest (RF) method. The RF model was trained and tested with numerical simulation results obtained through the Finite Element model, implemented with the Coupled Eulerian Lagrangian (CEL) approach. With the proposed CEL model, the effects of the stiff layer thickness, undrained shear strength ratio, and the undrained shear strength of the soft layer on the bearing characteristics, as well as the soil failure mechanism, were numerically studied. A simplified resistance profile model of penetration in stiff-over-soft clays is proposed, divided into three sections by the peak point and the transition point. The importance of soil parameters to the penetration resistance was analysed. Then, the trained RF model was tested against the test set, showing a good prediction of the numerical cases. Finally, the trained RF was validated against centrifuge tests. The RF model successfully captured the punch-through potential, and was verified using data recorded in the field, showing advantages over the SNAME guideline. It is supposed that the trained RF model should give a good prediction of the spudcan penetration resistance profile, especially if trained with more field data.

UNDRAINED SHEAR STRENGTH OF K0 CONSOLIDATED SOFT CLAYS UNDER TRIAXIAL AND PLANE STRAIN CONDITIONS

2014 ◽  
Vol 06 (03) ◽  
pp. 1450032 ◽  
Author(s):  
QIUSHENG WANG ◽  
XIULI DU ◽  
QIUMING GONG
Keyword(s):  
Shear Strength ◽  
Plane Strain ◽  
Yield Surface ◽  
Critical State ◽  
Volumetric Strain ◽  
Stress Path ◽  
Undrained Shear Strength ◽  
Triaxial Tests ◽  
Soft Clays ◽  
Undrained Shear

Theoretical formulas for predicting the undrained shear strength of K0 consolidated soft clays under the stress path related to triaxial and plane strain tests are presented within the framework of critical state soil mechanics. An inclined elliptical yield surface is adopted to take account of the initial anisotropic stress state. The undrained strength is determined by combining the undrained stress path in the volumetric stress–strain space and the initial yield surface in the deviator-mean stress space. The derived mathematical expressions are functions of the critical state frictional angle, the plastic volumetric strain ratio and the overconsolidation ratio, which can be simplified into the solutions for isotropically consolidated clays under triaxial tests or under plane strain tests. The results calculated by using the theoretical formulas obtained in this paper are in good agreement with the available collected test results. It indicates that these new formulas are applicable to triaxial and plane strain tests on normally and lightly to moderately overconsolidated soft clays.

Geotechnical properties of soft clays from the Witch Ground Basin, central North Sea

1991 ◽  
Vol 7 (1) ◽  
pp. 151-156 ◽  
Author(s):  
M. A. Paul ◽  
L. M. Jobson
Keyword(s):  
Shear Strength ◽  
Undrained Shear Strength ◽  
Geotechnical Properties ◽  
Seismic Surveys ◽  
Soft Clays ◽  
Fine Grained ◽  
Acoustic Signatures ◽  
The Witch ◽  
Central North Sea ◽  
Undrained Shear

AbstractThe Witch Ground Basin to the northeast of Peterhead is occupied by Late to Postglacial clays which reach a maximum thickness of over forty metres. High resolution seismic surveys have shown that the Sediments can be divided into two stratigraphic units on the basis of their acoustic signatures: the upper Witch Ground Formation shows in its lower part a finely detailed pattern of laterally continuous multiple reflectors, whereas the lower Swatchway and Coal Pit Formations present a disorganised signature in which few reflectors are continuous.Profiles of bulk density, water content and undrained shear strength have been obtained from two continuously sampled, adjacent boreholes which penetrated the sediments to a depth of forty metres. These show that the deposits of the Witch Ground Basin comprise a single geotechnical unit with the properties expected of a fine grained sediment of glaciomarine origin. The principal geotechnical properties change gradationally as a result of changes in composition and from selfweight compression. The different seismic signatures on which the basin stratigraphy is based are not reflected by major geotechnical changes within the sediment, but may well result from secondary features of the geotechnical profile.

Modified approach to evaluation of undrained shear strength from piezocone tests in soft clays

2015 ◽  
Vol 35 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Yaguo Zhang ◽  
Jingpei Li ◽  
Fayun Liang ◽  
Rui Fang ◽  
He Li
Keyword(s):  
Shear Strength ◽  
Undrained Shear Strength ◽  
Soft Clays ◽  
Undrained Shear

Undrained shear strength in stability calculation of embankments and foundations on soft clays

1980 ◽  
Vol 17 (4) ◽  
pp. 591-602 ◽  
Author(s):  
Rolf Larsson
Keyword(s):  
Shear Strength ◽  
Laboratory Tests ◽  
Undrained Shear Strength ◽  
Test Results ◽  
Stability Calculation ◽  
Soft Clays ◽  
Empirical Relations ◽  
Undrained Shear

Undrained shear strength of soft clays is usually measured by field vane tests or laboratory tests. The relevance of the test results in stability calculations of embankments and foundations is discussed. Empirical relations for undrained shear strengths obtained from Scandinavian clays are compared with reported failures.

Sign in / Sign up

Export Citation Format

Share Document