Shear strength measurement in soft mud deposits: application of GraviProbe and RheoTune

Soft mud deposits are increasingly encountered around the world, from natural offshore deposits and mud layers in estuaries, ports, and waterways to progressively growing leftover from treatment and extraction facilities, mines, and oil refineries. Reliable monitoring of the temporal and spatial strength buildup in such deposits is crucial to...

Numerical modeling of small-scale experiments for a coarse sand barrier as a measure against backward erosion piping: (Abstract)

Numerical simulation of the groundwater flow leading to sand boil reactivation in the Po River: (Paper and Abstract)

The reliability of river embankments is essential for flood risk management. The Po River, which flows through the North of Italy, is safeguarded over half of its length by major river embankments. Performance assessment of such water-retaining structures has become a major concern following some significant flood events in the past. Among the...

The influence of the leakage length on the initiation of backward erosion piping: (Paper and Abstract)

The earliest relation describing the risk of backward erosion piping, from Bligh in 1915, calculates an overall gradient over the dike. This gradient should be lower than a certain value depending on the material of the dike foundation for the dike to be safe. Later developments rationalize this number, showing the influence of grain size,...

Pipe measurement in small-scale backward erosion piping experiments: (Paper and Abstract)

Backward erosion piping is an important failure mechanism for water-retaining structures, a phenomenon that results in the formation of shallow pipes at the interface of a sandy or silty foundation and a cohesive cover layer. Although the pipe depth reveals a lot of information on the backward erosion process, it has never been measured...

Soil pressures at the cutting wheel and the pressure bulkhead of an EPB-shield

Model experiments on geosynthetic reinforced piled embankments, 3D test series

Overview geotechnical model tests on dike safety at Deltares

Three on-going dike safety studies (on: macro stability, piping and flow slides) in the Netherlands make use of geotechnical physical models. A short outline of these projects is presented; the physical models chosen are described and discussed. The three studies use different physical models, depending on the research questions at the beginning...

Bench-scale centrifuge testing to determine the hydraulic conductivity of clayey soils

The purpose of this research is to validate a mathematical model for flow through saturated and unsaturated porous media using a bench-scale centrifuge for an accurate determination of the hydraulic conductivity (function of the saturation degree of a soil) within a limited time at a reasonable price. The aim of this paper is to show preliminary...

Piping in loose sands – the importance of geometrical fixity of grains

Piping is one of the possible failure mechanism for dams and levees with a sandy foundation. Water flowing through the foundation causes the onset of grain transport, due to which shallow pipes are formed at the interface of the sandy layer and an impermeable blanket layer. In the past, the mechanism has been investigated predominantly in...

Model experiments on geosynthetic reinforced piled embankments, 3D test series

In the Netherlands, several field measurements were carried out in piled embankments with a geosynthetic basal reinforcement (GR). This paper presents a series of nineteen 3D model experiments on piled embankments. Purpose of the tests was to find an explanation why the calculated GR strains exceed the GR strains measured in the field. This...

Large-scale physical model tests on sand-filled geotextile tubes and containers under wave attack

Ten Years of bored tunnels in the Netherlands: Part I: Geotechnical issues

Ten years have passed since in 1997 for the first time construction of bored tunnels in the Netherlands soft soil was undertaken. Before that date essentially only immersed tunnels and cut-and-cover tunnels were constructed in the Netherlands. The first two bored tunnels were Pilot Projects, the 2nd Heinenoord tunnel and the Botlek Rail tunnel....

Ten years of bored tunnels in the Netherlands: Part II: Structural issues

In 1997 for the first time construction of bored tunnels in the Netherlands soft soil was undertaken. Before that date essentially only immersed tunnels and cut-and-cover tunnels were constructed in the Netherlands. The first two bored tunnels were Pilot Projects, the 2nd Heinenoord tunnel and the Botlek Rail tunnel. Since then a series of other...

Performance of optimal registration estimators

This paper derives a theoretical limit for image registration and presents an iterative estimator that achieves the limit. The variance of any parametric registration is bounded by the Cramer-Rao bound (CRB). This bound is signal-dependent and is proportional to the variance of input noise. Since most available registration techniques are biased...