|Title||Geotechnical data from a Champlain Sea clay landslide site at Breckenridge, southwestern Québec|
|Source||GeoOttawa 2017, conference program, abstracts/GeoOttawa 2017, programme de la conférence, résumés; by Canadian Geotechnical Society; 2017 p. 206 Open Access|
|Alt Series||Earth Sciences Sector, Contribution Series 20160287|
|Publisher||Canadian Geotechnical Society|
|Meeting||70th Canadian Geotechnical Conference; Ottawa; CA; October 1-4, 2017|
|Media||paper; on-line; digital|
|Lat/Long WENS|| -76.0000 -75.7500 45.5000 45.4167|
|Subjects||surficial geology/geomorphology; engineering geology; Nature and Environment; Science and Technology; Health and Safety; landslides; marine clays; sensitive clays; shear tests; shear strength; slope
stability analyses; slope failures; Champlain Sea Clay; Phanerozoic; Cenozoic; Quaternary|
|Program||Public Safety Geoscience Western Canada Geohazards Project|
|Released||2017 10 01|
|Abstract||This paper presents geotechnical test results from an ancient Champlain Sea clay landslide site at Breckenridge, southwestern Quebec. Cone penetration tests (CPT) and vane shear tests were conducted.
The CPT cone bearing factor Nkt was calibrated to be 11.5.The soil undrained shear strength (Cu) was found to have a correlation of Cu = 15 + 2.66 H (kPa), where H is depth in meters from the pre-failure ground surface at the head scarp. The slip
surface was found to be at about 15 m depth from the pre-failure ground surface. The soil properties suggest that the landslide unlikely occurred as a retrogressive failure commonly observed in sensitive clays (more likely an overall slope failure).
|Summary||(Plain Language Summary, not published)|
Geotechnical field testing was conducted at an ancient landslide site in Breckenridge, southwestern Quebec. The landslide occurred in Champlain Sea clay
about a thousand years ago. It is one of a cluster of landslides of different ages in the nearby area. The one studied in this paper was triggered by an earthquake that is known to have triggered multiple landslides in the southwestern Quebec region.
It is one of three landslides of the same age selected from the general region to evaluate the magnitude of the earthquake. The landslide is about 980 m long and 370 m wide. Field tests were conducted to measure the subsurface soil strength
parameters and other properties. Soil samples were taken from boreholes for laboratory testing to determine other material parameters. A shear plane was found to be at about 15 m depth from the original ground surface. This paper presents the factual
data obtained from the field and laboratory test programs, which can be used as reference by other researchers and practitioners working on similar problems in the region.