Pore pressures and permeabilities measured in marine sediments with a tethered probe

1991 ◽  
Vol 96 (B4) ◽  
pp. 5975-5984 ◽  
Author(s):  
E. E. Davis ◽  
G. C. Horel ◽  
R. D. MacDonald ◽  
H. Villinger ◽  
R. H. Bennett ◽  
...  
Author(s):  
C. C. Liao ◽  
H. Zhao ◽  
D.-S. Jeng

In this paper, we presented an integrated numerical model for the wave-induced pore pressures in marine sediments. Two mechanisms of the wave-induced pore pressures were considered. Both elastic components (for oscillatory) and the plastic components (for residual) were integrated to predict the wave-induced excess pore pressures and liquefaction in marine sediments. The proposed two-dimensional (2D) poro-elasto-plastic model can simulate the phenomenon of the pore pressure buildup and dissipation process in a sandy seabed. The proposed model overall agreed well with the previous wave experiments and geo-centrifuge tests. Based on the parametric study, first, we examined the effects of soil and wave characteristics on the pore pressure accumulations and residual liquefaction. Then, a set of analysis on liquefaction potential was presented to show the development of liquefaction zone. Numerical example shows that the pattern of progressive waves-induced liquefaction gradually changes from 2D to one-dimensional (1D), while the standing wave-induced liquefaction stays in a 2D pattern in the whole process.


2013 ◽  
Vol 2 (1) ◽  
pp. 91-94 ◽  
Author(s):  
Dawid Surmik ◽  
Tomasz Brachaniec

ABSTRACT An unusual large teeth, finding from time to time in marine sediments of Muschelkalk, Silesia, Poland indicate the superpredators occurrence. According to size and morphological features the teeth are similar to archosaurs or giant marine reptiles.


2011 ◽  
Vol 45 ◽  
pp. 32-49
Author(s):  
R. M. Gogorev ◽  
Z. V. Pushina

The richest diatom complexes have revealed due to the study of glacial-marine sediments sampled in the Fisher Massif (Prince Charles Mountains, East Antarctica) during 52nd and 53rd Russian Antarctic Expeditions (Polar Marine Geol. Survey Expedition) in 2006/07 and 2007/08. Three diatom complexes are distinguished according to different palaeoecological conditions: the planktonic one is located in the basis of the outcrop, while mixed planktonic-benthic and benthic ones being located above. The planktonic diatom complexes are dominated by two oceanic species Actinocyclus ingens (up to 8%) and Denticulopsis simonseni (up to 80%). There are 15 planktonic algae, e. g. Eucampia аntarctica, Fragilariopsis spp., Rhizosolenia spp., Rouxia antarctica, Podosira antarctica sp. nov., Stellarima microtrias; and also unknown and non-described benthic diatoms Achnanthes sp., Cocconeis spp., Rhabdonema (s. l.) spp. and Synedra (s. l.) spp. Detailed data on morphology and taxonomy of 10 centric diatoms are presented, including 3 newly described species.


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