Authors: Moreau, Ann-Laure; Locat, Jacques; Long, Bernard; Ouellet, Yvon

Source: Canadian Geotechnical Journal, Volume 44, Number 5, May 2007 , pp. 618-629(12)

Publisher: NRC Research Press

Abstract:

In 1996, following torrential rains, a layer of clean sediments was deposited in the upstream part of the Saguenay Fjord. This layer acted as a damping layer between contaminated sediments and the Saguenay waters. It is important to collect information on the water-sediments interface, which is the site of exchanges between the sediments and the waters. Three oceanographical campaigns have allowed us to obtain the data on the velocity of the benthic currents and the properties of the surface sediments. The velocities have been obtained by means of two current meters located at 3 m from the bottom and by means of registered videos. These two types of measurements have given comparable results. The main information collected on the sediments were their water content, grain size, density, and the presence of benthic fauna. The distribution of the main biogenic structure, the tubes of polychetes, is related to the depth of the site and to the grain size of the sediments. For the surface layer, large variations of the water content were obtained during the field measurements. Tests with an axial tomodensitometer have revealed a large variation in the density of the sediments in the top 2.5 cm.Key words: Saguenay Fjord, benthic sediments, axial tomodensitometer.[Journal translation]

En 1996, suite à des pluies diluviennes, une couche de sédiments propre s'est déposée dans la partie amont du fjord du Saguenay. Cette couche joue le rôle d'une couche tampon entre des sédiments contaminés et les eaux du Saguenay. Il est important de recueillir des informations concernant l'interface eau-sédiment, lieu d'échanges entre les sédiments et les eaux. Trois campagnes océanographiques ont permis d'obtenir des données concernant les vitesses des courants benthiques et les propriétés des sédiments superficiels. Les vitesses ont été obtenues à l'aide de deux courantomètres placés à 3 m du fond et à l'aide d'enregistrements vidéo. Ces deux types de mesures ont donné des résultats comparables. Les principales informations recueillies concernant les sédiments sont leur teneur en eau, leur granulométrie, leur masse volumique et la présence de faune benthique. La répartition de la principale structure biogène, les tubes de polychètes, est reliée à la profondeur du site et à la granulométrie des sédiments. Pour la couche de surface, de grandes variations de la teneur en eau ont été obtenues lors des mesures de terrain. Des essais avec un tomodensitomètre axial ont mis en évidence une grande variation de la masse volumique des sédiments sur les premiers 2,5 cm.Mots-clés : fjord du Saguenay, sédiments benthiques, tomodensitomètre axial.

Document Type: Research article

Publication date: 2007-05-01

More about this publication?

• Published since 1963, this monthly journal features articles, notes, and discussions related to new developments in geotechnical and geoenvironmental engineering, and applied sciences. The topics of papers written by researchers, theoreticians, and engineers/scientists active in industry include soil and rock mechanics, material properties and fundamental behaviour, site characterization, foundations, excavations, tunnels, dams and embankments, slopes, landslides, geological and rock engineering, ground improvement, hydrogeology and contaminant hydrogeology, geochemistry, waste management, geosynthetics, offshore engineering, ice, frozen ground and northern engineering, risk and reliability applications, and physical and numerical modelling. Papers on actual case records from practice are encouraged and frequently featured.
• Information for Authors
• Submit a Paper
• Subscribe to this Title
• Terms & Conditions
• Sample Issue
• Reprints & Permissions
• ingentaconnect is not responsible for the content or availability of external websites

Related content

• In this: publication
• By this: publisher
• In this Subject: Geology ,  General & Civil Engineering
• By this author: Moreau, Ann-Laure ;  Locat, Jacques ;  Long, Bernard ;  Ouellet, Yvon

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers