despite providing robustness, high-gain observers impose a peaking phenomenon, which may cause instability, on the system states. in this paper, an adaptive saturation is proposed to attenuate the undesirable mentioned phenomenon in high-gain observers. a real-valued and differentiable sigmoid function is considered as the saturating element whose parameters (height and slope) are adaptively tu...

A general methodology for the probabilistic evaluation of landslide hazard is applied, taking in account both the landslide susceptibility and the instability triggering factors, mainly rainfall. The method is applied in the FanhõesTrancão test site (north of Lisbon, Portugal) where 100 shallow translational slides were mapped and integrated into a GIS database. For the landslide susceptibility...

Three large scale field tests on dikes have been carried out at the IJkdijk test site in the Netherlands. Two tests involved piping, micro-instability of the sand core and erosion from overtopping. Both dikes failed on micro-instability. The third test involved slope stability with a deep sliding plane. All tests were done to validate monitoring systems and dike safety information systems. Seve...

CONTEXT Current research into the etiology of joint instability has yielded inconsistent results, limiting our understanding of how to prevent and treat ligamentous injury effectively. Recently, cortical reorganization was demonstrated in patients with ligamentous injury; however, these neural changes have not been assessed relative to joint laxity. OBJECTIVE The purpose of the current study ...

Understanding the failure mechanism and modes of multiface slopes in Wenchuan earthquake can provide a scientific guideline for slope seismic design. In this paper, two-dimensional particle flow code (PFC2D) shaking table tests are used to study slopes. The results show that with different moisture content under loads. 5%, 8%, 12% shattering-shallow slip, tension-shear shattering-collapse respe...

In Hong Kong, slope failure in weathered granite and volcanic rocks has been studied extensively, but the impact of hydrogeological conditions on slope stability has received much less attention. It is customary in Hong Kong to assume that the hydraulic conductivity (K) of weathered igneous rocks decreases with depth or as the rock mass becomes less weathered. Generally studies of groundwater f...

Transport networks play a crucial part in the global economy, with roads and railways being of particular importance at regional and national scales. However, roads and railways are founded on earthworks such as embankments, which can be susceptible to slope failure. Slope instability is a costly problem, which can lead to travel disruption, and injury or loss of life. Earthwork stability asses...

The present investigation is concerned with the role of bottom slope in the stability properties of two-dimensional disturbances in sheared two-layer immiscible fluids with stepwise densities. A linear analysis of normal mode instability of the interface in an inclined closed tube is carried out using full Navier-Stokes equation using Chebyshev-tau method. It has been observed that Reynolds num...

Within a GIS (geographical information system), spatial analysis techniques can be used to apply deterministic methods for identifying and mapping areas susceptible to shallow submarine mass movements. This paper describes such a method which allows spatially widespread, rapid, repeatable and cost-effective evaluation of shallow submarine slope risk. A deterministic approach has the advantage o...

[1] The dynamics associated with the propagation of unstable waves along a density front and their interaction with submarine canyons are simulated and analyzed with a fine-resolution three-dimensional primitive equation coastal ocean model. Simulations consider flow in an alongshore density front over two bottom topographies: an idealized straight shelf and a shelf incised by a canyon. The sta...