The Experts below are selected from a list of 78675 Experts worldwide ranked by ideXlab platform

Sara Bashah - One of the best experts on this subject based on the ideXlab platform.

  • carbonate slope morphology revealing a giant submarine canyon little bahama bank bahamas
    Geology, 2018
    Co-Authors: Thierry Mulder, Herve Gillet, Vincent Hanquiez, Emmanuelle Ducassou, Kelly Fauquembergue, Melanie Principaud, Gilles Conesa, Le J Goff, Jeremy Ragusa, Sara Bashah
    Abstract:

    New high-quality multibeam data detail the morphology of the giant 135-km-long Great Abaco Canyon (GAC) located between Little Bahama Bank (LBB, Bahamas) and Blake Plateau. Knickpoints, chutes, and plunge pools mark the canyon main axis, which is parallel to the LBB margin. The canyon head covers a large area but does not represent the main source of the modern sediments. The material supplied through the LBB canyon systems originates below this head, which only shows erosive lineaments related to the pathway of currents running along the seafloor and restricted failure scars. Most of the sediment supply originates from the canyon sides. The northern canyon flank incises the Blake Plateau, which comprises contourites on top of a drowned Cretaceous carbonate platform. These deposits are susceptible to translational slides and form dissymmetric debris accumulations along the northern edge of the canyon. A large tributary drains the Blake Plateau. Two large tributaries connecting the southern flank of the GAC directly to the LBB upper slope form additional sources of sediments. Subbottom profiles suggest the presence of a sedimentary levee on the tributary canyon and of sediment gravity flow deposits. The GAC has been a Permanent Structure since the drowning of the Cretaceous platform, and its size and morphology are comparable to those of canyons in siliciclastic environments. The orientation of the GAC parallel to large-scale regional tectonic Structures suggests a structural control. The size of the observed Structures, especially plunge pools at the base of gigantic chutes, is unusual on Earth. The presence of deposits downflow of the pools suggests that the GAC results from or at least is maintained by persistent and sustained submarine gravity flows rather than by retrogressive erosion.

Bashah S. - One of the best experts on this subject based on the ideXlab platform.

  • Carbonate slope morphology revealing a giant submarine canyon (Little Bahama Bank, Bahamas)
    'Geological Society of America', 2018
    Co-Authors: Mulder T., Gillet H., Ducassou E., Fauquembergue K., Principaud M., Conesa G., Le Goff J., Ragusa J., Bashah S.
    Abstract:

    International audienceNew high-quality multibeam data detail the morphology of the giant 135-km-long Great Abaco Canyon (GAC) located between Little Bahama Bank (LBB, Bahamas) and Blake Plateau. Knickpoints, chutes, and plunge pools mark the canyon main axis, which is parallel to the LBB margin. The canyon head covers a large area but does not represent the main source of the modern sediments. The material supplied through the LBB canyon systems originates below this head, which only shows erosive lineaments related to the pathway of currents running along the seafloor and restricted failure scars. Most of the sediment supply originates from the canyon sides. The northern canyon flank incises the Blake Plateau, which comprises contourites on top of a drowned Cretaceous carbonate platform. These deposits are susceptible to translational slides and form dissymmetric debris accumulations along the northern edge of the canyon. A large tributary drains the Blake Plateau. Two large tributaries connecting the southern flank of the GAC directly to the LBB upper slope form additional sources of sediments. Subbottom profiles suggest the presence of a sedimentary levee on the tributary canyon and of sediment gravity flow deposits. The GAC has been a Permanent Structure since the drowning of the Cretaceous platform, and its size and morphology are comparable to those of canyons in siliciclastic environments. The orientation of the GAC parallel to large-scale regional tectonic Structures suggests a structural control. The size of the observed Structures, especially plunge pools at the base of gigantic chutes, is unusual on Earth. The presence of deposits downflow of the pools suggests that the GAC results from or at least is maintained by persistent and sustained submarine gravity flows rather than by retrogressive erosion

Thierry Mulder - One of the best experts on this subject based on the ideXlab platform.

  • carbonate slope morphology revealing a giant submarine canyon little bahama bank bahamas
    Geology, 2018
    Co-Authors: Thierry Mulder, Herve Gillet, Vincent Hanquiez, Emmanuelle Ducassou, Kelly Fauquembergue, Melanie Principaud, Gilles Conesa, Le J Goff, Jeremy Ragusa, Sara Bashah
    Abstract:

    New high-quality multibeam data detail the morphology of the giant 135-km-long Great Abaco Canyon (GAC) located between Little Bahama Bank (LBB, Bahamas) and Blake Plateau. Knickpoints, chutes, and plunge pools mark the canyon main axis, which is parallel to the LBB margin. The canyon head covers a large area but does not represent the main source of the modern sediments. The material supplied through the LBB canyon systems originates below this head, which only shows erosive lineaments related to the pathway of currents running along the seafloor and restricted failure scars. Most of the sediment supply originates from the canyon sides. The northern canyon flank incises the Blake Plateau, which comprises contourites on top of a drowned Cretaceous carbonate platform. These deposits are susceptible to translational slides and form dissymmetric debris accumulations along the northern edge of the canyon. A large tributary drains the Blake Plateau. Two large tributaries connecting the southern flank of the GAC directly to the LBB upper slope form additional sources of sediments. Subbottom profiles suggest the presence of a sedimentary levee on the tributary canyon and of sediment gravity flow deposits. The GAC has been a Permanent Structure since the drowning of the Cretaceous platform, and its size and morphology are comparable to those of canyons in siliciclastic environments. The orientation of the GAC parallel to large-scale regional tectonic Structures suggests a structural control. The size of the observed Structures, especially plunge pools at the base of gigantic chutes, is unusual on Earth. The presence of deposits downflow of the pools suggests that the GAC results from or at least is maintained by persistent and sustained submarine gravity flows rather than by retrogressive erosion.

Mulder T. - One of the best experts on this subject based on the ideXlab platform.

  • Carbonate slope morphology revealing a giant submarine canyon (Little Bahama Bank, Bahamas)
    'Geological Society of America', 2018
    Co-Authors: Mulder T., Gillet H., Ducassou E., Fauquembergue K., Principaud M., Conesa G., Le Goff J., Ragusa J., Bashah S.
    Abstract:

    International audienceNew high-quality multibeam data detail the morphology of the giant 135-km-long Great Abaco Canyon (GAC) located between Little Bahama Bank (LBB, Bahamas) and Blake Plateau. Knickpoints, chutes, and plunge pools mark the canyon main axis, which is parallel to the LBB margin. The canyon head covers a large area but does not represent the main source of the modern sediments. The material supplied through the LBB canyon systems originates below this head, which only shows erosive lineaments related to the pathway of currents running along the seafloor and restricted failure scars. Most of the sediment supply originates from the canyon sides. The northern canyon flank incises the Blake Plateau, which comprises contourites on top of a drowned Cretaceous carbonate platform. These deposits are susceptible to translational slides and form dissymmetric debris accumulations along the northern edge of the canyon. A large tributary drains the Blake Plateau. Two large tributaries connecting the southern flank of the GAC directly to the LBB upper slope form additional sources of sediments. Subbottom profiles suggest the presence of a sedimentary levee on the tributary canyon and of sediment gravity flow deposits. The GAC has been a Permanent Structure since the drowning of the Cretaceous platform, and its size and morphology are comparable to those of canyons in siliciclastic environments. The orientation of the GAC parallel to large-scale regional tectonic Structures suggests a structural control. The size of the observed Structures, especially plunge pools at the base of gigantic chutes, is unusual on Earth. The presence of deposits downflow of the pools suggests that the GAC results from or at least is maintained by persistent and sustained submarine gravity flows rather than by retrogressive erosion

Kočičková Veronika - One of the best experts on this subject based on the ideXlab platform.

  • Návrh podzemní stěny ovlivněné výkopem z obou stran
    Vysoké učení technické v Brně. Fakulta stavební, 2017
    Co-Authors: Kočičková Veronika
    Abstract:

    The aim of this thesis was simplified design of diaphragm wall affected by excavation from both sides. This wall is a part of temporary shaft that serves for exchange of tunnel boring machines and at the same time it is a Permanent Structure of an adjacent metro station. Part of the thesis deals with description of construction sequence of diaphragm walls, excavation of the shaft, excavation of the adjacent metro station and following construction of metro tubes and backfilling of the shaft. Inseparable part of the thesis is assessment of geological conditions and geotechnical parameters. Furthermore, a study on temperature loads on struts was carried out and the results of the study were used for design of the struts. To fulfil the requirements of the assignment several models of the shaft Structure and adjacent metro station were built in program Plaxis and one model of the diaphragm wall of the shaft was created in program Geo5. The model outputs were subsequently compared to each other. Furthermore a model of lateral support frame was created in program Scia Engineer. Outputs from programs Plaxis and Scia Engineer were used as a basis for design checks of the Structure. The design checks were done according to Eurocodes. The diaphragm wall and the lateral support frame were designed to support the loads considered in this thesis. In order to simplify the calculation variable loads from construction machines were not considered and the only variable load considered was the temperature load on struts. Lateral support frame was also designed to accidental load – loss of a strut

  • Návrh podzemní stěny ovlivněné výkopem z obou stran
    Vysoké učení technické v Brně. Fakulta stavební, 2017
    Co-Authors: Kočičková Veronika
    Abstract:

    Cílem této diplomové práce byl zjednodušený návrh podzemní stěny ovlivněné výkopem z obou stran. Tato stěna je součástí dočasné šachty pro výměnu tunelovacích strojů a zároveň je trvalou konstrukcí přilehlé stanice metra. Součástí práce je popis postupu výstavby podzemních stěn, hloubení šachty, hloubení přilehlé stanice metra a následné vytvoření tunelových rour pro metro a zasypání šachty. Nedílnou součástí práce je pojednání o geologických podmínkách a zhodnocení geotechnických parametrů. Dále byla vypracována rešerše na téma teplotního namáhání rozpěr a výsledky této rešerše byly aplikovány na návrh rozpěr. Pro splnění požadavků zadání bylo vytvořeno několik modelů konstrukce šachty a přilehlé stanice metra v programu Plaxis a jeden model podzemní stěny šachty v programu Geo5. Výstupy z těchto modelů byly následně mezi sebou porovnány. Dále byl vytvořen model rozpěrného rámu v programu Scia Engineer. Výstupy z programů Plaxis a Scia Engineer byly použity jako podklad pro posouzení konstrukce. Toto posouzení bylo provedeno dle Eurokódů. Podzemní stěna i rozpěrný rám byly navrženy tak, aby přenesly účinky od zatížení, která byla uvažována v této práci. Pro zjednodušení byla zanedbána proměnná zatížení od pracovních strojů a jako jediné proměnné zatížení bylo uvažováno teplotní zatížení rozpěr. Rozpěrný rám byl také navržen na mimořádné zatížení – ztrátu rozpěry.The aim of this thesis was simplified design of diaphragm wall affected by excavation from both sides. This wall is a part of temporary shaft that serves for exchange of tunnel boring machines and at the same time it is a Permanent Structure of an adjacent metro station. Part of the thesis deals with description of construction sequence of diaphragm walls, excavation of the shaft, excavation of the adjacent metro station and following construction of metro tubes and backfilling of the shaft. Inseparable part of the thesis is assessment of geological conditions and geotechnical parameters. Furthermore, a study on temperature loads on struts was carried out and the results of the study were used for design of the struts. To fulfil the requirements of the assignment several models of the shaft Structure and adjacent metro station were built in program Plaxis and one model of the diaphragm wall of the shaft was created in program Geo5. The model outputs were subsequently compared to each other. Furthermore a model of lateral support frame was created in program Scia Engineer. Outputs from programs Plaxis and Scia Engineer were used as a basis for design checks of the Structure. The design checks were done according to Eurocodes. The diaphragm wall and the lateral support frame were designed to support the loads considered in this thesis. In order to simplify the calculation variable loads from construction machines were not considered and the only variable load considered was the temperature load on struts. Lateral support frame was also designed to accidental load – loss of a strut.