Regional geology and landslides in the marine clay deposits of eastern Canada

1970 ◽  
Vol 7 (2) ◽  
pp. 145-156 ◽  
Author(s):  
P. La Rochelle ◽  
J. Y. Chagnon ◽  
G. Lefebvre
Keyword(s):  
Shear Strength ◽  
Pore Water ◽  
Flow Conditions ◽  
Marine Clay ◽  
Eastern Canada ◽  
Regional Geology ◽  
Clay Deposits

A detailed inventory of the numerous landslides which have taken place in the Province of Quebec has shown that they are concentrated in given areas. Extensive studies carried out in three different areas have revealed a coincidence between the concentration of landslides and the existence of valleys in the bedrock underlying the clay deposits.Piezometric levels measured on the field have consistently shown the prevalence of a downward gradient in the upper part of the slope and an upward gradient with artesian pressure at the toe. These flow conditions which can be imputed in part to the presence of the valley in the bedrock produce the leaching of the salt in the pore water of the clay resulting in a decrease of the shear strength and an increase of sensitivity of the clay.

scholarly journals Soil disturbance from pile driving in sensitive clay

1978 ◽  
Vol 15 (3) ◽  
pp. 346-361 ◽  
Author(s):  
M. Bozozuk ◽  
B. H. Fellenius ◽  
L. Samson
Keyword(s):  
Pore Water ◽  
Ground Surface ◽  
Soil Disturbance ◽  
Pile Driving ◽  
Horizontal Distance ◽  
Lateral Movement ◽  
Marine Clay ◽  
Eastern Canada ◽  
Overburden Pressure ◽  
Pore Water Pressures

Soil disturbance due to the driving of two groups of 116 concrete piles each in sensitive marine clay was studied on a construction project in eastern Canada. Pore-water pressures, heave, and lateral movement of soil and piles, and tests of strength, compressibility, and consistency limits of the soil were observed prior to and up to 3 months after pile driving whereas observations of pore-water pressures were continued for an additional 5 months. Driving of the piles had little effect on the compressibility and consistency limits of the marine clay, but the in situ shear strength and cone penetration resistance were reduced by about 15 and 30%, respectively. Soil heave within the group of piles decreased linearly with depth from a maximum of 450 mm (18 in.) at the ground surface to about zero at the pile tips, and in volume amounted to approximately 55% of the soil displaced by the piles. The vertical heave outside the pile group was confined to a horizontal distance of 12 m (39 pile diameters). During pile driving, the lateral movement of previously driven piles was as much as 175 mm (7 in.). Horizontal soil movements measured by inclinometers varied up to 125 mm (5 in.). Pore-water pressures generated during piling exceeded the total overburden pressure by 35–40%. The excess pore pressures dissipated in about 8 months after the piling was completed.

Fourth Canadian Geotechnical Colloquium: Strength and slope stability in Canadian soft clay deposits

1981 ◽  
Vol 18 (3) ◽  
pp. 420-442 ◽  
Author(s):  
Guy Lefebvre
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Large Strain ◽  
Soft Clay ◽  
Peak Strength ◽  
Eastern Canada ◽  
Effective Stresses ◽  
Long Term Stability ◽  
Clay Deposits ◽  
Clay Slopes

It is generally admitted that the long term stability of clay slopes should be analysed in terms of effective stresses, which necessitates the knowledge of the pore pressure conditions and of the relationship between the shear strength and the effective stresses. This paper deals with the determination of shear strength for stability analysis of clay slopes in Eastern Canada. First the various concepts pertinent to slope stability in soft clay are examined and a certain justification of the use of the post-peak or large strain strength is demonstrated. In a second part, 14 case records of natural slopes or permanent excavation slopes are presented and analysed in terms of the post-peak strength. Finally, values of post-peak strength determined in the laboratory for more than 30 sites are presented and it is attempted to derive correlations by which the shear strength parameters could be readily approximated from other properties such as the apparent preconsolidation pressure or the vane strength.

Conjectures, Hypotheses, and Theories of Drumlin Formation (In memory of Stanislaw Baranowski)

1981 ◽  
Vol 27 (97) ◽  
pp. 503-505 ◽  
Author(s):  
Ian J. Smalley
Keyword(s):  
Shear Strength ◽  
Pore Water ◽  
Stress Level ◽  
Critical Stress ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Glacial Till ◽  
Forming Process ◽  
Stress Levels

AbstractRecent investigations have shown that various factors may affect the shear strength of glacial till and that these factors may be involved in the drumlin-forming process. The presence of frozen till in the deforming zone, variation in pore-water pressure in the till, and the occurrence of random patches of dense stony-till texture have been considered. The occurrence of dense stony till may relate to the dilatancy hypothesis and can be considered a likely drumlin-forming factor within the region of critical stress levels. The up-glacier stress level now appears to be the more important, and to provide a sharper division between drumlin-forming and non-drumlin-forming conditions.

An analysis of the stability of thawing slopes, Ellesmere Island, Nunavut, Canada

2000 ◽  
Vol 37 (2) ◽  
pp. 449-462 ◽  
Author(s):  
Charles Harris ◽  
Antoni G Lewkowicz
Keyword(s):  
Shear Strength ◽  
Pore Water ◽  
Active Layer ◽  
Factor Of Safety ◽  
High Arctic ◽  
Ellesmere Island ◽  
Sensitivity Analyses ◽  
Pore Water Pressures ◽  
Hot Weather ◽  
The Stability

Active-layer detachment slides are locally common on Fosheim Peninsula, Ellesmere Island, where permafrost is continuous, the active layer is 0.5-0.75 m thick, and summer temperatures are unusually high in comparison with much of the Canadian High Arctic. In this paper we report pore-water pressures at the base of the active layer, recorded in situ on two slopes in late July and early August 1995. These data form the basis for slope stability analyses based on effective stress conditions. During fieldwork, the factor of safety within an old detachment slide on a slope at Hot Weather Creek was slightly greater than unity. At "Big Slide Creek," on a slope showing no evidence of earlier detachment failures, the factor of safety was less than unity on a steep basal slope section but greater than unity elsewhere. In the upper slope, pore-water pressures were only just subcritical. Sensitivity analyses demonstrate that the stability of the shallow active layer is strongly influenced by changes in soil shear strength. Possible mechanisms for reduction in shear strength through time include weathering of soils and gradual increases in basal active layer ice content. However, we suggest here that soil shearing during annual gelifluction movements is most likely to progressively reduce shear strengths at the base of the active layer from peak values to close to residual, facilitating the triggering of active-layer detachment failures.Key words: detachment slides, Ellesmere Island, pore-water pressures, gelifluction.

scholarly journals Effect of Variable Confining Pressure on Cyclic Triaxial Behavior of K0-consolidated Soft Marine Clay

2018 ◽  
Vol 4 (4) ◽  
pp. 755
Author(s):  
Lei Sun
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Axial Strain ◽  
Water Pressure ◽  
Confining Pressure ◽  
Stress Path ◽  
Cyclic Stress ◽  
Marine Clay ◽  
Stress Ratios ◽  
Variable Confining Pressure

The effect of variable confining pressure (VCP) on the cyclic deformation and cyclic pore water pressure in K0-consolidated saturated soft marine clay were investigated with the help of the cyclic stress-controlled advanced dynamic triaxial test in undrained condition. The testing program encompassed three cyclic deviator stress ratios, CSR=0.189, 0.284 and 0.379 and three stress path inclinations ηampl=3,1 and 0.64. All tests with constant confining pressure (CCP) and variable confining pressure (VCP) have identical initial stress and average stress. The results were analyzed in terms of the accumulative normalized excess pore water pressure rqu recorded at the end of each stress cycle and permanent axial strain, as well as resilient modulus. Limited data suggest that these behavior are significantly affected by both of the VCP and CSR. For a given value of VCP, both of the pore water pressure rqu and permanent axial strains are consistently increase with the increasing values of CSR. However, for a given value of CSR, the extent of the influence of VCP and the trend is substantially depend on the CSR.

scholarly journals Triple-Binder-Stabilized Marine Deposit Clay for Better Sustainability

2020 ◽  
Vol 12 (11) ◽  
pp. 4633
Author(s):  
Mohamad Hanafi ◽  
Abdullah Ekinci ◽  
Ertug Aydin
Keyword(s):  
Mass Loss ◽  
Embodied Energy ◽  
Coarse Grained ◽  
Environmental Concerns ◽  
Marine Clay ◽  
The Third ◽  
Clay Deposits ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
The Cost

Marine clay deposits are commonly found worldwide. Considering the cost of dumping and related environmental concerns, an alternative solution involving the reuse of soils that have poor conditions is crucial. In this research, the authors examined the strength, microstructure, and wet–dry resistance of triple-binder composites of marine-deposited clays and compiled a corresponding database. In order to evaluate the wetting–drying resistance of the laboratory-produced samples, the accumulated mass loss (ALM) was calculated. The use of slag alone as a binder, at any percentage, increased the ALM up to 2%. However, the use of lime as the third binder seemed to accelerate the chemical reactions associated with the hydration of clay and cementitious material and to enhance the chemical stability, i.e., specimens that included both lime and slag experienced the same ALM as specimens treated with cement only. Scanning electron microscopy analysis confirmed the durability improvements of these clays. The proposed unconfined compressive strength–porosity and accumulated mass loss relationship yielded practical approximation for the fine- and coarse-grained soils blended with up to three binders until 60 days of curing. The laboratory-produced mixes showed reduction of embodied energy and embodied carbon dioxide (eCO2) emissions for the proposed models.

scholarly journals New geological data (Middle Triassic, Rhaetian-Liassic and Oligocene) of the Winterswijk quarry, the eastern Netherlands

2005 ◽  
Vol 84 (4) ◽  
pp. 409-413 ◽  
Author(s):  
G.F.W. Herngreen ◽  
J.H.A. van Konijnenburg - van Cittert ◽  
H.W. Oosterink
Keyword(s):  
Middle Triassic ◽  
Geological Data ◽  
Small Interval ◽  
Marine Clay ◽  
Black Clay ◽  
Lower Oligocene ◽  
Clay Deposits ◽  
Shale Formation ◽  
First Time ◽  
Lower Muschelkalk

AbstractThe present publication deals with recent palynological results of a relatively small interval of Muschelkalk and exposures of the overlying clay deposits in the Winterswijk quarries. For the first time the Lower Muschelkalk Member in the Netherlands could be independently dated as Bithynian (Anisian, Middle Triassic). Contrary to widely accepted opinions the overlying almost black clay deposit is not Liassic but Rhaetian in age and it is assigned to the Sleen Shale Formation. This marginal marine clay which pinches out to the south, is in turn overlain by a light gray, full-marine Lower-Oligocene clay of the Rupel Formation. An anomalous occurrence of Liassic clay is now attributed to subrosion of Röt salt followed by collapse of the overlying Muschelkalk, Rhaetian and Lias strata.

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