Breaching Flow Slides and the Associated Turbidity Currents: Large-Scale Experiments and 3D Numerical Modelling

Underwater slope failure is a common problem in the fields of geotechnical, dredging and hydraulic engineering, posing a major risk to submerged infrastructure and flood defences along coasts, rivers, and lakes. The term ‘flow slide’ refers to a specific, complex failure mechanism of underwater slopes, which occurs when a substantial amount of...

On the modelling of the unstable breaching process

Breaching is an important production mechanism for stationary suction dredgers. It is a process occurring in submerged sandy slopes, which mostly occurs in dense sandy soils with a low permeability. The process is initiated by the formation of a slope under water, whose angle is steeper than the internal friction angle, called the breach face....

Large-scale Experiments on Breaching Flow Slides and the Associated Turbidity Current

Breaching flow slides are accompanied by the generation of turbidity currents. Measurements of these currents are critical for understanding the interaction between the turbidity current and the slope surface, as well as for the validation of numerical models. However, there are insufficient data available detailing the velocity distribution or...

The need for experimental studies on breaching flow slides

Recent studies have revealed that breaching, rather than liquefaction, is the dominant failure process in underwater slopes of fine sand and the main driver of observed flow slides in nature. As a result, breaching is getting more attention from hydraulic and geotechnical researchers. Measurements of breaching-generated turbidity currents are...

Controlled water-level system for breach analysis of levees within an enhanced acceleration field

Correct scaling of breach analysis of river levees is a challenging task that is not easily accomplished by physical modelling. Several small-scale physical model tests have been conducted at 1-g level, which cannot truly represent the stress-dependency of soils, whereas the scaling issues arising from centrifuge modelling have not been fully...

Experimental investigation on breaching of embankments

Breaching of embankments has recently drawn more and more attention due to its importance in the development of early warning systems for embankment failures, in the evacuation plans of people at risk, in the design method of embankments based on a risk-approach, etc. The erosion process observed during embankment breaching tests in the...

PHYSICAL SCALE MODELING OF DREDGING PROCESSES IN SAND AND GRAVEL

Reliability analysis of a hydraulic fill with respect to liquefaction and breaching

A recently reclaimed site in the Port of Rotterdam will serve as location and foundation of an LNG terminal. LNG (Liquefied Natural Gas) is recognized as hazardous material and underlies strict safety requirements. As part of the safety assessment of the entire installation, a specific analysis had to be carried out concerning the geotechnical...

The Causes and Mechanisms of Historical Dike Failures in the Netherlands

In a historical perspective, flood protection in the past was not given high priority - plague and periods of famine and war took precedence. Poverty and a lack of knowledge made it difficult to create safer dikes. Dike engineering did improve in Napoleonic era due to the French Central Government, but many dikes still failed. A historical...

Breach growth in clay-dikes

Numerous flood disasters occur every year worldwide, mostly resulting from failure of dikes, some with catastrophic outcomes. Examples are the dike failures along the Yangtze River in China in 1931 due to heavy rainstorms and those in the Netherlands in 1953 due to a storm surge at the North Sea. Both floods induced many deaths and enormous...

Advances in one-dimensional numerical breach modeling of sand barriers

A hydrodynamic numerical model is formulated to describe the breach erosion process of sandy barriers. The breach flow is based on the system of unsteady shallow water equations, which is solved using a robust upwind numerical approach in conjunction with the Finite Volume Method (FVM). The hydraulic jump is considered as part of the breach flow...

Numerical modeling of wave overwash on low-crested sand barriers

For management of coastal breaching hazards it is critical to be able to assess the potential of coastal barrier breaching as a result of wave actions during storm surges (wave overwash). This phenomenon is known as the breach initiation phase; the mechanisms behind this are not very well understood. In the present study, laboratory experiments...

Numerical modelling of wave overwash at low-crested sand barriers

In overwash beaches, response of a barrier profile as a whole to storm wave attacks can be distinguished into seaward and landward parts that are associated with two respective across-shore driving processes i.e. surge erosion, and overwash. Modeling of overwash relies heavily on the specification of wave overtopping from the seaside (see...

Numerical modelling of slope formation with sand mining

Comparison and validation of two Dutch models of breach growth in sandy dikes

In order to develop a new philosophy of flood safety in terms of probability of a certain level, two mathematical models of breach growth in sandy dikes have become available to determine the flood discharge in case of dike failure. BREACHES 1.0, developed at Alkyon/Delft Hydraulics (Steetzel) and BRES 1.0 at Delft University of Technology ...

Breaching of dunes - Preliminary quantification of related mechanism and assessment of the probability of occurrence

In order to yield an expression for the probability of breaching, in this desk study the mechanism that play a role in the initiation of breaching of dunes are described and preliminary quantified. In addition a pragmatic description for the assessment of the combined probability of breaching is elaborated. From this it was concluded that...

A field experiment on beach growth in sand-dikes

The set-up and results of a field experiment on sand-dike breach erosion are described, It is found that the breaching process for the 2.2 m high sand-dike is similar to that in Visser's (1988) laboratory experiments with a 0.6 m high sand-dike. Confrontation of Visser's (1988) breach erosion model with the field data shows reasonable agreement...