Showing papers by "Marc-André Bérubé published in 1986"

Black shale heaving at Sainte-Foy, Quebec, Canada

Abstract: Oxidation of pyrite and crystallization of sulphate minerals in rock fractures have locally produced ground heaving in excess of 10 cm in the foundations of a college at Sainte-Foy, near Quebec (Quebec). Black shales of the Sainte-Foy Formation are involved; they contain about 2% disseminated framboidal pyrite and 3% calcite. Reaction products identified with a scanning electron microscope (SEM) equipped with an energy-dispersive X-ray chemical analyser (EDXA) are iron hydroxides and numerous sulphate minerals containing calcium, iron, potassium, aluminum, magnesium, manganese, barium, and strontium. In Ontario, heaving of black shales has been observed in the Ottawa area in particular; rock expansion there was mainly attributed to crystallization of gypsum along the bedding plane cleavages of the shales. At Sainte-Foy, fibroferrite, a fibrous iron–aluminum sulphate mineral, probably also contributed significantly to heaving.

Utilisation du céléromètre ultrasonique sur des sols cohérents

Abstract: The recent developments in acoustical methods make it possible to obtain, in the laboratory, quick and simple measures of the speed of propagation of the compression (Vp) and shear (Vs) waves in cohesive saturated or nonsaturated soils. The ultrasonic celerometer has allowed the observation of a significant correlation between the speed of the shear waves and the shear strength measured with the Swedish cone in clayey soils with or without additives. This nondestructive test could be currently used in geotechnical practice. Key words: ustrasonic celerometer, dynamic-elastic constants, nondestructive test, laboratory test, acoustic method, Swedish cone shear strength, cohesive soils, shear wave speed, compression wave speed. [Journal translation]