Cyclic strength of a sensitive clay of Eastern Canada

1980 ◽  
Vol 17 (5) ◽  
pp. 85
Keyword(s):  
Cyclic Strength ◽  
Eastern Canada ◽  
Sensitive Clay

Cyclic strength of a sensitive clay of eastern Canada

1979 ◽  
Vol 16 (1) ◽  
pp. 163-176 ◽  
Author(s):  
Kenneth L. Lee
Keyword(s):  
Cyclic Loading ◽  
Shear Zones ◽  
Cyclic Strength ◽  
Earth Dam ◽  
Eastern Canada ◽  
Two Samples ◽  
Dam Site ◽  
Loading Tests ◽  
Sensitive Clay ◽  
Cyclic Loading Tests

Cyclic loading tests were performed on many undisturbed specimens and a few compacted specimens of two samples of very sensitive clay from an earth dam site on the Outardes River in Quebec. Failure occurred when one or more thin shear zones developed in which the remolded soil was reduced to a liquid, while the rest of the specimen remained intact, strong, and brittle. The cyclic strength of this clay was high in comparison to that required for the foundation of a planned earth dike and was relatively strong in comparison with other clays. However, simplified analyses indicate that under some conditions dynamic loading can be expected to induce instability in this type of soil.

Nouvelle Autoroute 30: a Champlain clay crust earthworks case study

2015 ◽  
Vol 52 (3) ◽  
pp. 295-304 ◽  
Author(s):  
Chris Barker ◽  
Alan Phear ◽  
François Côté ◽  
David Garcia Cueto
Keyword(s):  
Moisture Content ◽  
Optimum Moisture Content ◽  
Value Engineering ◽  
Eastern Canada ◽  
Crust Layer ◽  
Engineering Problems ◽  
Sensitive Clay ◽  
High Road ◽  
St Lawrence River

The Champlain Sea Basin in eastern Canada is known for its sensitive clay and associated engineering problems through this much-developed area along the St Lawrence River. Geologically, the surface of the Champlain clay has been subjected to desiccation, frost action, and weathering. This has resulted in the reduction of the water content and sensitivity of the surficial crust layer of this very wet clay deposit sufficiently to enable it to be used as an earthworks material. However, the material is still much wetter than its optimum moisture content. By co-operative value engineering, the team on the Nouvelle Autoroute 30 project in Montréal, Quebec, investigated and achieved moisture content and degree of compaction derogations to the Ministry of Transport, Quebec specification. This allowed the successful construction of many low and high road embankments using an unprecedented 2.3 × 106 m3 of this weathered Champlain clay crust material. This paper describes how the design and construction issues associated with using this material for earthworks were evaluated and addressed.

A massive sensitive clay landslide, Quyon Valley, southwestern Quebec, Canada, and evidence for a paleoearthquake triggering mechanism

2013 ◽  
Vol 80 (3) ◽  
pp. 425-434 ◽  
Author(s):  
Gregory R. Brooks
Keyword(s):  
Seismic Zone ◽  
Earthquake Triggering ◽  
Triggering Mechanism ◽  
Eastern Canada ◽  
The West ◽  
Close Link ◽  
Regional Seismicity ◽  
Close Proximity ◽  
Sensitive Clay ◽  
Glaciomarine Sediments

A landslide debris field covering ~ 31 km2, the presence of large sediment blocks up to hundreds of meters long, and the exposure of deposits of a single landslide along the incised course of the Quyon River are evidence of a massive failure of sensitive Champlain Sea glaciomarine sediments along the lower Quyon Valley, southwestern Quebec, Canada. Seventeen radiocarbon ages indicate that the failure occurred between 980 and 1060 cal yr BP. Twenty-four additional radiocarbon ages reveal that nine landslides within a 65-km belt in the Quyon"Ottawa area also occurred at approximately this time. In combination, the contemporaneous occurrence of ten landslides between 980 and 1060 cal yr BP, the setting or morphology of five of the other failures, and the close proximity of two of the failures to the Quyon Valley landslide provide circumstantial evidence of a paleoearthquake-triggering mechanism. The paleoearthquake is estimated to be Mw ~ 6.1 or larger, with the epicenter within the West Quebec Seismic Zone. A common earthquake-triggering mechanism for the three largest landslides in eastern Canada suggests a close link between massive failures of sensitive glaciomarine sediments and the regional seismicity.

Use of terrestrial laser scanning for the characterization of retrogressive landslides in sensitive clay and rotational landslides in river banks

2009 ◽  
Vol 46 (12) ◽  
pp. 1379-1390 ◽  
Author(s):  
Michel Jaboyedoff ◽  
Denis Demers ◽  
Jacques Locat ◽  
Ariane Locat ◽  
Pascal Locat ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Emergency Situation ◽  
Light Detection And Ranging ◽  
Eastern Canada ◽  
Landslide Volume ◽  
Digital Elevation ◽  
Sensitive Clay ◽  
River Banks

For more than 10 years, digital elevation models (DEM) produced by light detection and ranging (LIDAR) technology have provided new tools for geomorphologic studies and especially for landslide studies. In particular, terrestrial laser scanning (TLS) provides a great versatility of use. TLS can be used either for monitoring purposes or in an emergency situation that necessitates a rapid DEM acquisition for assessing a hazard. Using three examples we demonstrate the usefulness of TLS for landslide volume quantification, profile creation, and time series analysis. These case studies are landslides located in sensitive clays of eastern Canada (Quebec, Canada) or small rotational slides in river banks (Switzerland).

A new method of sampling in sensitive clay

1979 ◽  
Vol 16 (1) ◽  
pp. 226-233 ◽  
Author(s):  
Guy Lefebvre ◽  
Claude Poulin
Keyword(s):  
Large Diameter ◽  
Ground Surface ◽  
Sampling Technique ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Eastern Canada ◽  
Bentonite Slurry ◽  
Block Sampling ◽  
Sensitive Clay

Many recent publications on the influence of sampling techniques indicate that, generally speaking, the quality of the samples increases with the diameter of the sampling equipment. However, all studies also conclude that even the large diameter samplers available on the market substantially damage the structure of the clays of eastern Canada, as compared to the sample quality obtained by block sampling. In addition to the difficulties associated with the excavation of the trenches necessary for block sampling, the depth of block sampling is limited, at least in soft clays.The sampling technique described in the present paper allows the retrieval of deep blocks, working from the ground surface and using a cutting method quite similar to that used for conventional block sampling. The large diameter borehole is filled with water or bentonite slurry to reduce the possibility of bottom heave. By comparing the results of unconfined compression tests it is shown that the samples obtained by this method are of a quality equal or superior to that of blocks sampled conventionally at the bottom of open cuts.

Seasonal diving and foraging behaviour of Eastern Canada-West Greenland bowhead whales

2020 ◽  
Vol 643 ◽  
pp. 197-217 ◽  
Author(s):  
SME Fortune ◽  
SH Ferguson ◽  
AW Trites ◽  
B LeBlanc ◽  
V LeMay ◽  
...  
Keyword(s):  
Climate Change ◽  
Late Summer ◽  
Calanoid Copepods ◽  
Eastern Canada ◽  
West Greenland ◽  
Bowhead Whales ◽  
Seasonal Movement ◽  
Dive Behaviour ◽  
Calanus Glacialis ◽  
Canada West

Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.

The generalized regularities of damageability and integrity in estimations of the endurance in conditions of variability of loading regimes

2019 ◽  
Vol 85 (9) ◽  
pp. 61-65
Author(s):  
N. A. Makhutov
Keyword(s):  
Life Time ◽  
Cyclic Strength ◽  
Laboratory Diagnostics ◽  
Methodological Issues ◽  
Break Points ◽  
Number Of Cycles ◽  
Cyclic Damage ◽  
Damage Summation ◽  
Temperature Factors

We consider and analyze general methodological issues regarding the strength and endurance (life-time) of the materials and structure elements under a combined effect of various force, deformation and temperature factors. The Journal "Zavodskaya laboratoriya. Diagnostika materialov" (Industrial laboratory. Diagnostics of materials) has launched systematic publications on this problematic since 2018. For many decades, domestic and foreign laboratory studies have gleaned to a traditional methodology for obtaining initial curves of the long-term and cyclic strength that related the breaking stresses with time or number of cycles. These curves, with the characteristic sections and break points, separating the areas of elastic and inelastic (plastic strain or creep strain) strain, are used in analysis of long-term and cyclic damage. Using the elementary linear law of damage summation, it is possible to calculate at a first approximation the strength and endurance under varying conditions of loading. Stepping up the requirements to the accuracy of calculations necessitates a transition from force fracture criteria (at stresses a) to deformation criteria (in elastic and inelastic deformations e). Thus, it becomes possible to construct and use a unified expression for the curve of the long-term cyclic fracture (taking into account the temporal x and cyclic N factors) and a long-term cyclic damage. With such approach it is possible to remain the linear law of damage summation though those damages are obviously nonlinear. The goal of the study is to continue and support the discussion of the most complex problems of a comprehensive assessment of the strength, resource, survivability and safety of high-risk engineering equipment within the journal pages.

Sign in / Sign up

Export Citation Format

Share Document