A statistical evaluation of some engineering properties of eastern Canadian clays

1990 ◽  
Vol 27 (3) ◽  
pp. 373-386 ◽  
Author(s):  
Étienne J. Windisch ◽  
Raymond N. Yong
Keyword(s):  
Shear Strength ◽  
Statistical Evaluation ◽  
Undrained Shear Strength ◽  
Plasticity Index ◽  
Engineering Properties ◽  
Plastic Limit ◽  
Liquidity Index ◽  
Marine Clays ◽  
Undrained Shear

Statistics for data collected on eastern Canadian clays (Champlain, Goldthwait, Tyrrell, and Laflamme marine clays and Barlow–Ojibway lacustrine clays) are computed and analyzed. These clays are divided into three groups: eastern Canadian marine clays, Champlain clays (as an important part of the first group), and Barlow–Ojibway lacustrine clays. The analysis reveals significant differences between eastern Canadian clays and Scandinavian clays. Some relationships proposed in the literature and based on plasticity index, liquidity index, and plastic limit are found to be inapplicable to eastern Canadian clays. On the basis of a proposed method for estimating the undrained shear strength of normally consolidated eastern Canadian marine clays, the overconsolidation ratio is found to be equal to the ratio of the in situ undrained shear strength to the estimated normally consolidated undrained shear strength. Key words: undrained shear strength, plasticity index, liquidity index, plastic limit, statistical evaluation, over-consolidation ratio, lacustrian clays.

Relationship between measured plastic limit and plastic limit estimated from undrained shear strength, water content ratio and liquidity index

Clay Minerals ◽  
2017 ◽  
Vol 52 (4) ◽  
pp. 509-519 ◽  
Author(s):  
Giovanni Spagnoli ◽  
Martin Feinendegen
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Human Error ◽  
Undrained Shear Strength ◽  
Plastic Limit ◽  
Limit Values ◽  
Liquidity Index ◽  
Content Ratio ◽  
Exponential Trend ◽  
Undrained Shear

AbstractThe detection of the plastic limit of clays is subject to human error. Several attempts have been made to correlate across studies the geotechnical properties of fine-grained soils (water content, liquidity index, shear strength, etc.). Based on the premise that the liquidity index and water content ratio can be correlated directly, an alternative method to obtain indirectly the plastic limit is suggested here. The present study investigated 40 natural clayey samples of various mineralogies and origins and other publicly available data, where Atterberg limits and undrained shear strength values obtained with the vane shear tests were given. The liquidity index and water-content ratio correlate very well for defined undrained shear strength values of the clays. Solving the liquidity index equation for the plastic limit, estimated plastic limit values obtained by the liquidity index/water-content ratio relationship were compared with laboratory plastic-limit values. Preliminary results based on 62 values show an exponential trend with a multiple regression coefficient of 0.79. The data need to be confirmed on a larger database, however.

Halloysite behaving badly: geomechanics and slope behaviour of halloysite-rich soils

Clay Minerals ◽  
2016 ◽  
Vol 51 (3) ◽  
pp. 517-528 ◽  
Author(s):  
Vicki Moon
Keyword(s):  
Shear Strength ◽  
Bulk Density ◽  
High Mobility ◽  
Undrained Shear Strength ◽  
Field Conditions ◽  
High Peak ◽  
Plasticity Index ◽  
Undrained Shear

AbstractHalloysite-rich soils derived fromin situweathering of volcanic materials support steep stable slopes, but commonly fail under triggers of earthquakes or rainfall. Resulting landslides are slideflow processes, ranging from small translational slides to larger rotational failures with scarps characteristic of sensitive soils. Remoulding of failed materials results in high-mobility flows with apparent friction angles of 10–16°. The materials characteristically have high peak-friction angles (∼25– 37°), low cohesion (∼12–60 kN m−2) and plasticity ( plasticity index ∼10–48%), and low dry bulk density (∼480–1,080 kg m−3) with small pores due to the small size of the halloysite minerals. They remain saturated under most field conditions, with liquidity indexes frequently >1. Remoulded materials have limited cohesion (<5 kN m−2) and variable residual friction angles (15°–35°). Halloysite mineral morphology affects the rheology of remoulded suspensions: tubular minerals have greater viscosity and undrained shear strength than spherical morphologies.

In-Situ Undrained Shear Strength of Two Marine Clays

1976 ◽  
Vol 102 (9) ◽  
pp. 989-1005
Author(s):  
Demetrious C. Koutsoftas ◽  
Joseph A. Fischer
Keyword(s):  
Shear Strength ◽  
Undrained Shear Strength ◽  
Marine Clays ◽  
Undrained Shear

scholarly journals The undrained strength – liquidity index relationship

2014 ◽  
Vol 51 (9) ◽  
pp. 1073-1086 ◽  
Author(s):  
P.J. Vardanega ◽  
S.K. Haigh
Keyword(s):  
Shear Strength ◽  
Undrained Shear Strength ◽  
Liquid Limit ◽  
Mathematical Function ◽  
Plastic Limit ◽  
Mathematical Relationship ◽  
Liquidity Index ◽  
Undrained Strength ◽  
Statistical Improvement ◽  
Undrained Shear

A database of 641 fall cone tests on 101 soil samples from 12 countries has been analysed to determine the best mathematical relationship linking undrained shear strength with liquidity index. From the database, it is shown that the use of a linear relationship linking liquidity index and the logarithm of undrained shear strength that uses the commonly assumed 100-fold factor increase in strength from the liquid to plastic limit overpredicts the measured data of soil strength. The use of a factor of about 35 for the ratio between the strength at liquid limit and that extrapolated to the plastic limit is shown to be more realistic. Logarithmic liquidity index is examined and found to also correlate strongly with the logarithm of undrained shear strength; however, it is shown that no great statistical improvement is present compared with the semi-logarithmic formulation. When considering data of individual soils a power law fitting is statistically shown to be the preferred mathematical function.

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