Erosion of Soft Cohesive Sediment Deposits

Parchure, Trimbak M.; Mehta, Ashish J.

doi:10.1061/(asce)0733-9429(1985)111:10(1308)

Cited by 396 publications

(226 citation statements)

References 7 publications

Supporting

Mentioning

211

Contrasting

Unclassified

Order By: Relevance

“…Black et al [2002] has listed some of the biological effects that can affect sediment erosion. Other works have mentioned the impact of chemical factors [Parchure and Mehta, 1985;Ravisangar et al, 2001] or unsaturation on erosion. We particularly focus on particle interaction for saturated conditions: matric suction effects need not to be taken into account.…”

Section: Cohesion Modelingmentioning

confidence: 99%

Erosion threshold of saturated natural cohesive sediments: Modeling and experiments

Ternat

Boyer

Anselmet

et al. 2008

Water Resources Research

View full text Add to dashboard Cite

[1] Predicting the erosion resistance of saturated natural sediments requires taking into account cohesion, which results from interactions between clay particles. The current paper describes a combined experimental and theoretical examination of the threshold conditions for a mixture of clays and sands. Erosion threshold measured values are larger than those predicted from noncohesive models. Beyond the usual dependence on grain size, a significant correlation between erosion threshold and porosity measurements is confirmed for heterogenous mixtures of grains with particle Reynolds number lower than 5, for pH values in the range of 6-8, and under freshwater conditions. A model of the erosion criterion is proposed. First, a cohesion force between two spherical particles is introduced into the usual erosion criterion. This reveals a specific function of the cohesion force, called cohesion function. The force we consider is the long-range van der Waals interaction. Then, multiple interactions between one particle and those surrounding it are counted and modeled on the basis of both the coordination number and the porosity. Finally, the overall erosion threshold for the sediment bed is inferred from the average of the multiple interactions over the grain size distribution. The model highlights that cohesion comes from clay particles (about 2 10 À6 m) and can affect the entire grain size range (from clays to sands) by means of coordination. The model relevance is assessed by comparison with experimental thresholds obtained from resuspension campaigns. The results show that the proposed cohesion model offers good agreement with experimental data.

show abstract

Section: Cohesion Modelingmentioning

confidence: 99%

Erosion threshold of saturated natural cohesive sediments: Modeling and experiments

Ternat

Boyer

Anselmet

et al. 2008

Water Resources Research

View full text Add to dashboard Cite

show abstract

“…The erosion and transport of sediments is a key problem for many fields, both in nature and industry, such as in the coastal engineering regarding the prediction of estuary and river bed evolution [21,35], or in the civil engineering concerning the safety of embankment dams and dikes [12,13]. Within this latter context of great social relevance, there are statistical estimates [22] showing that surface erosion, which generally results from an overflowing of the earthwork, causes about 50% of the embankment dam and levee failures whereas a slightly smaller proportion can be attributed to internal erosion induced by water infiltration through the embankment or its foundation.…”

Section: Introductionmentioning

confidence: 99%

Erosion onset of a cohesionless granular medium by an immersed impinging round jet

Brunier-Coulin¹,

Cuéllar²,

Philippe³

2017

Phys. Rev. Fluids

View full text Add to dashboard Cite

To cite this version: AbstractAmong different devices developed quite recently to quantify the resistance to erosion of a natural soil within the broader context of dyke safety, the most commonly used is probably the Jet Erosion Test (JET) in which a scouring crater is induced by impingement of an immersed water jet. A comprehensive experimental investigation on the jet erosion in the specific situation of a cohesionless granular material is presented here. The tests were performed combining special optical techniques allowing for an accurate measurement of the scouring onset and evolution inside an artificially translucent granular sample. The impinging jet hydrodynamics are also analyzed empirically validating the use of a self-similar theoretical framework for the laminar round jet. The critical conditions at the onset of erosion appear to be best described by a dimensionless Shields number based on the inertial drag force created by the fluid flow on the eroded particles rather than on the pressure gradients around them. To conclude, a tentative empirical model for the maximal flow velocity initiating erosion at the bottom of the scoured crater is put forward and discussed in the light of some preliminary results.

show abstract

“…For instance, τ Cr commonly increases with depth due to the effects of consolidation, thereby limiting the extent of erosion under a given bed shear stress. The erosion behavior under such conditions is referred to as depth-limited or type I erosion (Mehta and Partheniades 1982) and can be formulated as (Parchure and Mehta 1985;Amos et al 1992) E ¼ E f exp ∝ τ b −τ Cr;z τ Cr;z ! β 8 < :…”

Section: Introductionmentioning

confidence: 99%

“…Equation (1) and its variants have been implemented in numerical sediment transport models for numerous applications around the world. Such applications typically rely on either parameterization derived from physical measurements of the erosion properties, achieved using a number of different devices and approaches such as the Gust microcosm (Gust and Mueller 1997), Sedflume (McNeil et al 1996), carousels (Parchure and Mehta 1985;Amos et al 1992;Maa et al 1993), soil mechanical properties (Winterwerp et al 2012), etc., or rely on model calibration to suspended sediment concentration (SSC) measurements (Van Kessel et al 2011;Van Maren et al 2015). The experimental methods vary in complexity in terms of sample requirements (for example, undisturbed cores versus grab samples), ex situ versus in situ measurements, laboratory equipment (for example, specialized flumes versus conventional soil mechanical measurements), sediment strata sampled (for example, thin layers near the bed surface versus larger depth intervals but deeper in the bed), etc.…”

Section: Introductionmentioning

confidence: 99%

Surficial sediment erodibility from time-series measurements of suspended sediment concentrations: development and validation

Mathew

Winterwerp

2017

Ocean Dynamics

View full text Add to dashboard Cite

Numerical models of fine sediment transport depend on different approaches to parameterize the erosion properties of surficial sediment strata. These properties, namely the critical shear stress for erosion and the erosion rate coefficient, are crucial for reproducing the short-term and long-term sediment dynamics of the system. Methods to parameterize these properties involve either specialized laboratory measurements on sediment samples or optimization by model calibration. Based on observations of regular patterns in the variation of suspended sediment concentrations (SSC) over the tidal cycle in a small, narrow estuary, an alternate approach, referred to as the entrainment flux method, for quantifying the erosion properties of surficial bed strata is formulated and applied. The results of this method are shown to be analogous to the erosion data used to formulate the standard linear erosion formulation developed by various authors. The erosion properties inferred from the entrainment flux method are also compared to direct measurements of erodibility on sediment samples from the same site using the Gust microcosm apparatus. The favorable comparison of the two approaches suggests that the entrainment flux method can be used to infer and quantify the erodibility of surficial sediment strata in similar small and narrow estuaries. This method has certain advantages, chiefly its ease of implementation and the fact that it uses SSC time series which would typically be expected to be available for the study of or for model application at a given site. Guidelines for selecting the appropriate dataset for the application of the method are also presented.

show abstract

Erosion of Soft Cohesive Sediment Deposits

Cited by 396 publications

References 7 publications

Erosion threshold of saturated natural cohesive sediments: Modeling and experiments

Erosion threshold of saturated natural cohesive sediments: Modeling and experiments

Erosion onset of a cohesionless granular medium by an immersed impinging round jet

Surficial sediment erodibility from time-series measurements of suspended sediment concentrations: development and validation

Contact Info

Product

Resources

About