scholarly journals Laboratory seismic measurements for layer-specific description of fluid mud and for linking seismic velocities to rheological properties

2021 ◽  
Vol 149 (6) ◽  
pp. 3862-3877
Author(s):  
Xu Ma ◽  
Alex Kirichek ◽  
Ahmad Shakeel ◽  
Karel Heller ◽  
Deyan Draganov
Keyword(s):  
Rheological Properties ◽  
Seismic Velocities ◽  
Fluid Mud ◽  
Specific Description ◽  
Seismic Measurements

Strategies for Measuring Fluid Mud Layers and Their Rheological Properties in Ports

2017 ◽  
Vol 143 (4) ◽  
pp. 04017008 ◽  
Author(s):  
Juliane Castro Carneiro ◽  
Diego Luiz Fonseca ◽  
Susana Beatriz Vinzon ◽  
Marcos Nicolás Gallo
Keyword(s):  
Rheological Properties ◽  
Fluid Mud

scholarly journals Rheology of Mud: An Overview for Ports and Waterways Applications

2021 ◽  
Author(s):  
Ahmad Shakeel ◽  
Alex Kirichek ◽  
Claire Chassagne
Keyword(s):  
Organic Matter ◽  
Rheological Properties ◽  
Organic Matter Content ◽  
Matter Content ◽  
Point Of View ◽  
Sampling Location ◽  
Fluid Mud ◽  
Systematic Analysis ◽  
Semi Empirical ◽  
Cohesive Material

Mud, a cohesive material, consists of water, clay minerals, sand, silt and small quantities of organic matter (i.e., biopolymers). Amongst the different mud layers formed by human or natural activities, the fluid mud layer found on top of all the others is quite important from navigational point of view in ports and waterways. Rheological properties of fluid mud layers play an important role in navigation through fluid mud and in fluid mud transport. However, the rheological properties of mud are known to vary as a function of sampling location within a port, sampling depth and sampling location across the globe. Therefore, this variability in rheological fingerprint of mud requires a detailed and systematic analysis. This chapter presents two different sampling techniques and the measured rheological properties of mud, obtained from laboratory experiments. The six protocols used to measure the yield stresses are detailed and compared. Furthermore, the empirical or semi-empirical models that are commonly used to fit rheological experimental data of such systems are presented. The influence of different factors such as density and organic matter content on the rheological behavior of mud is discussed. The fluidic yield stress of mud samples was observed to vary from 0.2 Pa to 500 Pa as a function of density and organic matter content.

scholarly journals Influence of microheterogeneity on effective stress law for elastic properties of rocks

Geophysics ◽  
2008 ◽  
Vol 73 (1) ◽  
pp. E7-E14 ◽  
Author(s):  
Radim Ciz ◽  
Anthony F. Siggins ◽  
Boris Gurevich ◽  
Jack Dvorkin
Keyword(s):  
Effective Stress ◽  
Seismic Data ◽  
Elastic Moduli ◽  
Seismic Velocity ◽  
Time Lapse ◽  
Seismic Velocities ◽  
Laboratory Measurements ◽  
Hydrocarbon Production ◽  
Stress Coefficient ◽  
Seismic Measurements

Understanding the effective stress coefficient for seismic velocity is important for geophysical applications such as overpressure prediction from seismic data as well as for hydrocarbon production and monitoring using time-lapse seismic measurements. This quantity is still not completely understood. Laboratory measurements show that the seismic velocities as a function of effective stress yield effective stress coefficients less than one and usually vary between 0.5 and 1. At the same time, theoretical analysis shows that for an idealized monomineral rock, the effective stress coefficient for elastic moduli (and therefore also for seismic velocities) will always equal one. We explore whether this deviation of the effective stress coefficient from unity can be caused by the spatial microheterogeneity of the rock. The results show that only a small amount (less than 1%) of a very soft component is sufficient to cause this effect. Such soft material may be present in grain contact areas of many rocks and may explain the variation observed experimentally.

Sediment sampling and soil properties of sediments in the Hamburg port and the river Elbe in comparison with hydro-acoustic measurements

2020 ◽  
Author(s):  
Nino Ohle ◽  
Thomas Thies ◽  
Rolf Lüschow ◽  
Ulrich Schmekel
Keyword(s):  
Boundary Conditions ◽  
Soil Properties ◽  
Rheological Properties ◽  
In Situ Monitoring ◽  
Rheological Parameters ◽  
Fluid Mud ◽  
Acoustic Measurements ◽  
Port Authority ◽  
River Elbe

<p>For future strategies in water depth maintenance in the Port of Hamburg, determining the navigability limit (i.e. the nautical safe depth) is of major importance. For this purpose, a project "Nautical Depth" was set up at the Hamburg Port Authority (HPA), which is dedicated to dealing with this issue. The aim is to measure a nautical safe depth under various boundary conditions and to identify limits for a safe passage of high concentrated soil suspensions. Among other things, the project cooperates with the Antwerp Port Authority, the Port of Rotterdam and the TU Delft. The project is also embedded in a research platform or network called MUDNET (www.tudelft.nl/mudnet).</p><p>In order to achieve the required acceptance for a reassessment of the nautical depth, it is necessary to determine the rheological properties of soil suspensions in-situ. The rheological parameters - which will be used to describe the nautical depth - have still to be determined. For a permanent identification of nautical relevant rheological properties of the soil suspensions, existing in-situ measuring devices have been tested and, under certain circumstances, new equipment has to be developed. However, these devices cannot be used for the spatial determination of the rheological properties but will reproduce these on cross-sections and depth profiles. Therefore, new evaluation algorithms should be developed in echo-sounding technology - which have to be correlated with the in-situ rheological properties - in order to ensure spatial representations of a safe nautical depth.</p><p>In a first step, measurements of nature conditions in the water column and at the riverbed were carried out in 9 areas and in 12 measuring campaigns in 2018 and 2019 in the Hamburg Port. Therefore, different sediment profiler devices (Rheotune, Graviprobe, Admodus USP) have been tested. Sediment samples were taken with a modified Frahm-Lot. All investigations were combined with hydro-acoustic measurements which includes multibeam echo-sounders and sub-bottom profilers with Silas processing software.</p><p>The presentation will give a closer look to the sampling strategies and results of the different soil properties within the Hamburg port and the river Elbe, which serves as fairway to the port. The investigations show that the soil properties are dependent from local and regional boundary conditions, as flow velocity, grain size distribution and especially in Hamburg from the organic matters and nutrients within the suspended and the soil material. Moreover, the laboratory data will be compared with hydro-acoustical and in-situ monitoring devices. Advantages and disadvantages of the different systems will be discussed.</p><p>Kamphuis et al. (2013) Fluid Mud and Determining, Nautical Dept Hydro International, 22-25;</p><p>Malcherek, A. et al. (2011) Zur Rheologie von Flüssigschlicken: Experimentelle Untersuchungen und theoretische Ansätze, Mitteilungen des Instituts für Wasserwessen der Universität der Bundeswehr, München 111:1-191;</p><p>Metha et al. (2013) Fluid Mud Properties in Nautical Depth Estimation, Journal of Waterway, Port, Coastal & Ocean Engineering, 140:210-222;</p><p>Ohle, N. et al (2019) Introduction and first results within the project “Nautical Depth” in Hamburg, 11<sup>th</sup> International SedNet conference, 3-5 April 2019, Dubrovnik;</p>

Assessing rheological properties of fluid mud samples through tuning fork data

2018 ◽  
Vol 69 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Diego Luiz Fonseca ◽  
Patrícia Cunha Marroig ◽  
Juliane Castro Carneiro ◽  
Marcos Nicolás Gallo ◽  
Susana Beatriz Vinzón
Keyword(s):  
Rheological Properties ◽  
Tuning Fork ◽  
Fluid Mud

scholarly journals Rheological analysis of mud from Port of Hamburg, Germany

2019 ◽  
Vol 20 (6) ◽  
pp. 2553-2562 ◽  
Author(s):  
Ahmad Shakeel ◽  
Alex Kirichek ◽  
Claire Chassagne
Keyword(s):  
Rheological Properties ◽  
Yield Stress ◽  
Measurement Techniques ◽  
Organic Matter Content ◽  
Matter Content ◽  
Rheological Parameters ◽  
Fluid Mud ◽  
Frequency Sweep ◽  
Rheological Analysis ◽  
Stress Dependent

Abstract 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.

scholarly journals A Laboratory Study on Rheological Properties of Fluid Mud

2012 ◽  
Vol 24 (3) ◽  
pp. 203-209 ◽  
Author(s):  
Dinh Phuc Nguyen ◽  
Eui-Taek Jung ◽  
Kun-Chul Park ◽  
Kyu-Nam Hwang
Keyword(s):  
Rheological Properties ◽  
Laboratory Study ◽  
Fluid Mud
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