Rheological properties of dense natural cohesive sediments subject to shear loadings

Yang, Wenyu; Yu, Guoliang; Tan, Soon Keat; Wang, Huakun

doi:10.1016/s1001-6279(14)60059-7

Cited by 52 publications

(20 citation statements)

References 25 publications

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“…From the oscillatory experiments, two regions were identified: elastic and viscous. Yang et al (2014b) also investigated the rheological characteristics of three different cohesive sediments from the Yangtze River, and shoal of the Hangzhou Bay and Yangcheng Lake (China). The results revealed three different deformation regions in the flow curves obtained from shear rate sweep tests.…”

Section: Introductionmentioning

confidence: 99%

Rheological analysis of mud from Port of Hamburg, Germany

2019

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Purpose An innovative way to define navigable fluid mud layers is to make use of their rheological properties, in particular their yield stress. In order to help the development of in situ measurement techniques, it is essential that the key rheological parameters are estimated beforehand. Is there only one yield stress? In which shear rate/shear stress range is yield expected to occur? How is yield stress dependent on depths and locations in the harbor? In order to answer these questions, we investigated the changes in the rheological properties of mud from along the river stream in the Port of Hamburg, Germany, using a recently developed laboratory protocol. Materials and methods In this study, a detailed rheological analysis was carried out on the mud samples collected from different locations and depths of the Port of Hamburg. A variety of rheological tests was performed including: stress sweep tests, flow curves, thixotropic tests, oscillatory amplitude, and frequency sweep tests. Results and discussion The yield stresses of sediments from different locations were significantly dissimilar from each other due to differences in densities and organic matter content. Two yield stresses (termed static and fluidic) were observed for every sample and linearly correlated to each other. The thixotropic studies showed that all mud samples, except from one location, displayed a combination of thixotropic and anti-thixotropic behaviors. The results of frequency sweep tests showed the solid-like character of the sediments within the linear viscoelastic limit. The yield stresses, thixotropy, and moduli of the mud samples increased by going deeper into the sediment bed due to the increase in density of the sediments. Conclusions This study confirmed the applicability of the recently developed protocol as a fast and reliable tool to measure the yield stresses of sediments from different locations and depths in the Port of Hamburg. The fluid mud layer, in all the locations it was observed, exhibited relatively small yield stress values and weak thixotropic behavior. This confirms that despite the fact that rheology of fluid mud is complex, this layer can be navigable.

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Section: Introductionmentioning

confidence: 99%

Rheological analysis of mud from Port of Hamburg, Germany

2019

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“…A yield stress becomes apparent in the hemipelagic sediment at a particle concentration of~10% and increases with increasing particle concentration. Figure 2a also shows the yield stress as a function of particle concentration measured in other studies (Coussot & Piau, 1994;Coussot et al, 1996;Huang & García, 1998;Malet et al, 2005;Remaitre et al, 2005;Maciel et al, 2009;Santolo et al, 2010;Blasio et al, 2011;Manga & Bonini, 2012;Jeong, 2013;Yang et al, 2014;Tran et al, 2015). In Figure 2, non-natural sediments are represented with squares.…”

Section: Resultsmentioning

confidence: 79%

Rheology of Natural Sediments and Its Influence on the Settling of Dropstones in Hemipelagic Marine Sediment

Knappe

Manga

Friant

2020

Earth and Space Science

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We investigate the rheology of naturally occurring hemipelagic marine sediment and compare measurements to another naturally occurring sediment from a terrestrial mud volcano and literature values. The hemipelagic marine sediment, collected by IODP 340, has a median grain size of 5.5 microns, is poorly sorted, and contains 31% clay, including smectite. The yield stresses and consistency are calculated by applying a range of shear stresses and shear rates using a cone‐and‐plate rheometer. A Herschel‐Bulkley model is fit to measured shear stresses and shear rates to calculate the yield stress and consistency. These measurements are performed at a range of particle concentrations and show that the hemipelagic sediment has a yield stress at particle concentrations as low as 10%. Increasing particle concentration increases the yield stress and consistency. We apply our results to show that natural pumice clasts need to have a radius greater than about 1 cm in order to settle through hemipelagic sediment on the sea floor. Most recovered pumice clasts from IODP 340 are thus preserved in the same horizon in which they were deposited.

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“…In this study, the vane method was used and was based on the application of a constant, low shear rate to the vane sensor for a certain time interval [ James et al ., ; Barnes and Nguyen , ; Faas and Wartel , ]. A shear rate of

\dot{γ}

= 0.1 s −1 for 1800 s was selected [ Yang et al ., ]. Based on the vane method, the static yield stress could be defined as the maximum stress obtained from the shear stress‐time response graph.…”

Section: Methodsmentioning

confidence: 99%

Critical conditions of incipient motion of cohesive sediments

Zhang

2017

Water Resources Research

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The critical condition of incipient motion of cohesive sediments was investigated in a laboratory study. One‐hundred experimental runs were performed with sediment samples by varying the yield stress to determine the relationship between the critical condition of incipient motion and the rheological properties of the cohesive sediments. The results indicate that yield stress is a factor that has a major influence on the incipient motion of cohesive sediments. In addition, the critical Shields parameter is found to be exponentially proportional to the yield stress and inversely proportional to the median grain size. The effect of yield stress on the critical Shields parameter is significant for the cohesive sediments and becomes progressively weaker with increasing median grain size. Furthermore, an empirical formula for calculating the critical Shields parameter of cohesive sediments that includes a rheological term and a gravity term is proposed by introducing the yield stress. According to this formula, a modified Shields diagram is obtained in which the values of the critical Shields parameter for cohesive sediments vary within a band that contains countless curves (instead of on a single line) to reflect the influence of the yield stress. This modification of the traditional Shields curve is effective for fine sediments, but the effects tend to vanish for coarse sediments as the behavior of sediments changes from cohesive to noncohesive. Finally, potential further investigations are discussed.

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Rheological properties of dense natural cohesive sediments subject to shear loadings

Cited by 52 publications

References 25 publications

Rheological analysis of mud from Port of Hamburg, Germany

Rheological analysis of mud from Port of Hamburg, Germany

Rheology of Natural Sediments and Its Influence on the Settling of Dropstones in Hemipelagic Marine Sediment

Critical conditions of incipient motion of cohesive sediments

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