New stability method for embankments on clay foundations

1982 ◽  
Vol 19 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Robert P. Chapuis
Keyword(s):  
Shear Strength ◽  
Stress Analysis ◽  
Undrained Shear Strength ◽  
Direct Application ◽  
Published Data ◽  
Total Stress ◽  
Preconsolidation Pressure ◽  
Stability Method ◽  
Undrained Shear ◽  
Clay Foundations

The proposed method makes use of a conventional total stress analysis, corrected to take into consideration the preconsolidation pressure and the undrained shear strength profiles. Good results are obtained for seven well documented cases of embankment failures, the data of which allow a direct application of the proposed method. Many other failure cases, for which the published data are insufficient to allow such a direct application, are analysed on a statistical basis using a relationship between cuσp′ and Ip. Bjerrum's correction appears as a particular case, only statistically applicable, of the proposed method.

Origine de la préconsolidation des argiles du Saguenay, Québec

1983 ◽  
Vol 20 (2) ◽  
pp. 315-328 ◽  
Author(s):  
R. Bouchard ◽  
D. J. Dion ◽  
F. Tavenas
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Ground Surface ◽  
Undrained Shear Strength ◽  
Geological History ◽  
Eastern Canada ◽  
Geotechnical Data ◽  
Preconsolidation Pressure ◽  
Undrained Shear ◽  
Good Agreement

The clays of Eastern Canada, and in particular the Saint-Jean-Vianney clay in the Saguenay region, have often been described as clays with a preconsolidation due partly to cementation. In order to check this assumption, the geological history and the geomorphology of the Saguenay region have been analyzed. Further to the evidence of significant erosion, available geotechnical data in the form of variations of water content, undrained shear strength, and preconsolidation pressure have been analyzed to determine the elevation of the original ground surface in the hypothesis of a preconsolidation resulting from deposition and erosion. The results of this analysis are in good agreement with the geological and geomorphological data and they suggest that cementation has had a negligible effect on the preconsolidation of the Saguenay clays. A regional map of preconsolidation pressures is also presented. Keywords: clay, preconsolidation, geomorphology, erosion, shear strength. [Journal translation]

Evaluation of Flow Liquefaction and Liquefied Strength Using the Cone Penetration Test: an update

2021 ◽  
Author(s):  
Peter Robertson
Keyword(s):  
Shear Strength ◽  
Large Strain ◽  
Strength Loss ◽  
Undrained Shear Strength ◽  
Technical Note ◽  
Published Data ◽  
Recent Experience ◽  
Case Histories ◽  
Flow Liquefaction ◽  
Undrained Shear

Robertson (2010a) outlined a method to evaluate the susceptibility of soils to undrained strength loss that could result in flow liquefaction as well as a method to estimate the resulting liquefied undrained shear strength of predominately sand-like soils using the CPT. Based on published data and recent case histories this technical note describes a recommended update to the Robertson (2010a) method to estimate the large strain liquefied or remolded undrained shear strength for both sand-like and clay-like soils as well as soils and that transition from sand-like to clay-like. The proposed update acknowledges that soil behavior can vary from sand-like to clay-like and that CPT interpretation to estimate large strain undrained shear strength changes due to the changing drainage conditions during the CPT. The updated method builds upon previously published data combined with recent experience and case histories.

scholarly journals Effects of compaction on soil undrained shear strength deteriorating during undrained cyclic loading and controlling seismic stability of embankment

2019 ◽  
Vol 92 ◽  
pp. 18003 ◽  
Author(s):  
Antoine Duttine ◽  
Fumio Tatsuoka ◽  
Kazuhiro Ueno
Keyword(s):  
Shear Strength ◽  
Cyclic Loading ◽  
Seismic Analysis ◽  
Undrained Shear Strength ◽  
Seismic Stability ◽  
Triaxial Tests ◽  
Response Analysis ◽  
Total Stress ◽  
Earth Fill ◽  
Undrained Shear

Effects of compaction on the undrained shear strength of saturated earth-fill dam materials are presented. Poorly and well compacted saturated soils may exhibit undrained shear strengths, respectively, significantly lower and higher than corresponding drained shear strength and this trend is amplified as the undrained strength deteriorates by preceding undrained cyclic loading. These features are implemented in a new simplified seismic analysis to evaluate residual deformation of earth-fill dams. The analysis consists of: 1) a modified Newmark sliding block analysis; and 2) a pseudo-static non-linear FEM analysis, both formulated in a unified framework based on the cumulative damage concept, total stress earthquake response analysis and a direct total stress modelling of undrained monotonic and cyclic stress-strain behaviours obtained by triaxial tests. The analysis simulates very well the collapse of an earth-fill dam by the 2011 Off the Pacific Coast of Tohoku Earthquake, Japan, and indicates a substantially higher seismic stability under the same conditions of the newly restored dam completed in 2017. Paramount effects of soil compaction on the seismic stability of earth-filled dam are demonstrated.

Profiling of overconsolidation ratio in clays by field vane

1988 ◽  
Vol 25 (1) ◽  
pp. 150-157 ◽  
Author(s):  
Paul W. Mayne ◽  
James K. Mitchell
Keyword(s):  
Shear Strength ◽  
Strain Rate ◽  
Undrained Shear Strength ◽  
Correction Factors ◽  
Test Results ◽  
Overconsolidation Ratio ◽  
Empirical Correction ◽  
Preconsolidation Pressure ◽  
Undrained Strength ◽  
Undrained Shear

The field vane (FV) has traditionally been utilized to obtain profiles of undrained shear strength in soft to medium clays. After some 40 years of experience with FV results, it has been suggested that empirical correction factors be applied to the FV data to account for the effects of strain rate, anisotropy, and disturbance on measured shear strengths. As an additional use of the device, the FV may be calibrated at each site to develop profiles of overconsolidation ratio (OCR) with depth. A data base of oedometer test results and FV strengths from 96 different clays has been compiled to use as a basis for this calibration. Key words: field vane, undrained strength, clay, overconsolidation ratio, preconsolidation pressure, shear strength, vane shear.

scholarly journals Evaluation of Undrained Shear Strength of Miocene Clay from the Weight Sounding Test (WST)

2017 ◽  
Vol 62 (2) ◽  
pp. 367-384
Author(s):  
Sebastian Olesiak
Keyword(s):  
Shear Strength ◽  
Field Testing ◽  
Field Investigation ◽  
Undrained Shear Strength ◽  
Cohesive Soils ◽  
Strength Parameters ◽  
Additional Measurement ◽  
Carpathian Foredeep ◽  
Innovative Solution ◽  
Undrained Shear

Abstract Soil strength parameters needed for the calculation of bearing capacity and stability are increasingly determined from field testing. This paper presents a method to determine the undrained shear strength cuWST of the soil, based on the Weight Sounding Test (WST). The innovative solution which allows for a significant reduction of equipment needed for geotechnical field investigation is presented. The proposed method is based on an additional measurement of the torque during testing. It then becomes possible to estimate the undrained shear strength, cuWST of the soil, using the correlation given in this paper. The research results presented in this paper were carried out on selected cohesive soils, Miocene clays from the Carpathian Foredeep.

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