ROCK SLOPES WITH OPEN FILTERS UNDER WAVE LOADING: EFFECTS OF STORM DURATION AND WATER LEVEL VARIATIONS

2017 ◽  
pp. 6
Author(s):  
Marcel R.A. Van Gent ◽  
Guido Wolters ◽  
Ivo M. Van der Werf
Keyword(s):  
Water Level ◽  
Physical Model ◽  
Cost Savings ◽  
Design Guidelines ◽  
Model Tests ◽  
Physical Model Tests ◽  
Storm Duration ◽  
Hydraulic Load ◽  
Loading Effects ◽  
Water Level Variations

Rubble mound breakwaters and revetments typically contain granular filters in one or more layers. The transition from the armour layer to the filter layer, and transitions between other layers within the structure, are normally geometrically tight to prevent material washout. This requires a limited ratio of the material size of the upper layer and neighbouring layer. An alternative is a geometrically open filter where in principle underlayer material can be transported into the upper layer, but if the hydraulic load at this transition between two layers remains low, the transition can be designed such that no or limited transport occurs, see for instance Van Gent and Wolters (2015), Van Gent et al (2015) and Jacobsen et al, (2017). This allows for larger ratios of material sizes, which can reduce the number of filter layers, and relax the material requirements with respect to the width of gradings. This can lead to considerable cost savings. In Van Gent and Wolters (2015) physical model tests for the transition between a layer of rock and an underlayer that consists of sand have been performed and design guidelines have been derived. Here, additional physical model tests are presented to study the influence of the storm duration and water level variations on the response of sand underneath a layer of rock.

scholarly journals EFFECTS OF WATER LEVEL VARIATIONS ON THE STABILITY OF ROCK ARMOURED SLOPES

2018 ◽  
pp. 44 ◽  
Author(s):  
Marcel R.A. Van Gent ◽  
Suzanna A.A. Zwanenburg ◽  
Jan Kramer
Keyword(s):  
Water Level ◽  
Physical Model ◽  
Model Tests ◽  
Water Levels ◽  
Level Variation ◽  
Water Level Variation ◽  
Stepwise Approach ◽  
Physical Model Tests ◽  
Water Level Variations ◽  
The Stability

Physical model tests on the stability of rock armoured slopes have been performed to demonstrate the importance of water level variations during a storm, due to a tide or a storm surge. For the stability of rock armoured slopes also the importance of the sequence of storms at various water levels has been studied. The test results indicate that a smooth sinusoidal water level variation leads to an increase in damage compared to the same wave conditions at a constant water level. Furthermore, a stepwise approach of the sinusoidal water level elevation leads to other results than the approach with a continuous water level variation, whereas the continuous water level variation resembles the peak of a storm or the tidal water level variation better than a stepwise approach. If storms with different water levels attack the armour layer, the damage is generally smaller than if all storms attack the armour layer at the same water level. Furthermore, the results have been discussed based on earlier analyses where the statistics of rock armoured slopes have been addressed and the importance of the length effect has been illustrated using a method to apply results from physical model tests to real structures.

scholarly journals Deformation Mechanism of Deposit Landslide Induced by Fluctuations of Reservoir Water Level Based on Physical Model Tests

2021 ◽  
Author(s):  
Zihua Jiang ◽  
Huanling Wang ◽  
Weichau Xie
Keyword(s):  
Water Level ◽  
Physical Model ◽  
Failure Process ◽  
Model Tests ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Deformation And Failure ◽  
Landslide Stability ◽  
Level Difference ◽  
Physical Model Tests

Abstract Located in reservoir area of Dahuaqiao Hydropower Station in Lancang River, the Dahua ancient deposit landslide exhibits high possibility of reactivation due to reservoir impoundment. In this study, physical model tests are conducted to investigate the variations of groundwater, deformation, and failure process of the landslide under different fluctuation speeds of reservoir water level. Influence of groundwater on landslide stability when reservoir water level fluctuating is analyzed then. Results indicate that the seepage pressure caused by water level difference can increase landslide displacement. During the dropping process of reservoir water level, the relationship between landslide displacement and water level difference can be described by a power function model. Groundwater has negative effects on stability of landslides, and the damage is characterized by traction landslide. More attentions should be paid on the displacement of the front edge of the landslide during the first rise and drop of reservoir water level. The study provides indispensable information for scheduling reservoir water level in the Dahuaqiao and others similar reservoir areas, thus having vital importance.

scholarly journals ADAPTATION WORKS TO AVOID THE FLOODING OF PIAZZA SAN MARCO (VENICE): PHYSICAL MODEL TESTS TO EVALUATE OVERTOPPING DISCHARGE

2020 ◽  
pp. 32
Author(s):  
Luca Martinelli ◽  
Chiara Favaretto ◽  
Matteo Volpato ◽  
Piero Ruol
Keyword(s):  
Water Level ◽  
Physical Model ◽  
Model Tests ◽  
Mitigation Option ◽  
Wave Overtopping ◽  
Physical Model Tests ◽  
Venetian Lagoon ◽  
A Minor ◽  
Minor Extent

According to the management of the Mo.S.E. system, the water level in the Venetian lagoon is maintained below a certain threshold, that however does not guarantee the complete defense of the main Piazza. Flooding of the Piazza is presently tolerated, although limitedly to a minor extent, and can/will be avoided only thanks to additional adaptation works. One of the possible flooding mechanisms is the wave overtopping, and this note investigates the efficiency, as possible mitigation option, of a small temporary barrier placed along the S. Marco quay.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/wiSF2B81wIM

scholarly journals PORT RESONANCE MITIGATION MODELED INTRODUCING ARJ-R STRUCTURES

2020 ◽  
pp. 38
Author(s):  
Jose A. GONZALEZ-ESCRIVA ◽  
Josep R. MEDINA ◽  
Joaquin M. GARRIDO
Keyword(s):  
Reflection Coefficient ◽  
Physical Model ◽  
Large Scale ◽  
Low Frequency ◽  
Model Tests ◽  
Wave Interference ◽  
Low Frequency Oscillations ◽  
Physical Model Tests ◽  
Similar Cost ◽  
Interference Mechanism

ARJ-R caissons are based on the "long-circuit" concept (Medina et al, 2016) that allows the extension of the destructive wave interference mechanism to mitigate low frequency oscillations without enlarging the width of the caisson. The performance of the ARJ-R caissons is referred to its reflection coefficient (Cr) which was obtained through large-scale physical model tests (Gonzalez-Escriva et al, 2018). In this paper, the effectiveness of Anti-Reflective Jarlan-type structures for Port Resonance mitigation (ARJ-R) has been assessed numerically for the port of Denia (Spain). ARJ-R structures are constructible, with similar dimensions as conventional vertical quay caissons and with a similar cost (15percent more than conventional vertical caisson).Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/LomQEVpvjik

scholarly journals OPTIMIZATION OF THE WAVECAT WAVE ENERGY CONVERTER

2012 ◽  
Vol 1 (33) ◽  
pp. 5 ◽  
Author(s):  
Hernan Fernandez ◽  
Gregorio Iglesias ◽  
Rodrigo Carballo ◽  
Alberte Castro ◽  
Marcos Sánchez ◽  
...  
Keyword(s):  
Physical Model ◽  
Wave Energy ◽  
Model Tests ◽  
Irregular Waves ◽  
Intermediate Water ◽  
Plan View ◽  
Santiago De Compostela ◽  
Wave Energy Converters ◽  
Physical Model Tests ◽  
The Difference

The development of efficient, reliable Wave Energy Converters (WECs) is a prerequisite for wave energy to become a commercially viable energy source. Intensive research is currently under way on a number of WECs, among which WaveCat©—a new WEC recently patented by the University of Santiago de Compostela. In this sense, this paper describes the WaveCat concept and its ongoing development and optimization. WaveCat is a floating WEC intended for operation in intermediate water depths (50–100 m). Like a catamaran, it consists of two hulls—from which it derives its name. The difference with a conventional catamaran is that the hulls are not parallel but convergent; they are joined at the stern, forming a wedge in plan view. Physical model tests of a 1:30 model were conducted in a wave tank using both regular and irregular waves. In addition to the waves and overtopping rates, the model displacements were monitored using a non-intrusive system. The results of the physical model tests will be used to validate the 3D numerical model, which in turn will be used to optimize the design of WaveCat for best performance under a given set of wave conditions.

scholarly journals LARGE AND SMALL SCALE WAVE OVERTOPPING MEASUREMENTS FOR AFSLUITDIJK REHABILITATION PROJECT

2020 ◽  
pp. 15
Author(s):  
Wouter Ockeloen ◽  
Coen Kuiper ◽  
Sjoerd van den Steen
Keyword(s):  
Water Management ◽  
Physical Model ◽  
Large Scale ◽  
Wadden Sea ◽  
Model Tests ◽  
Small Scale ◽  
Water Safety ◽  
Wave Overtopping ◽  
Physical Model Tests ◽  
Large Scale Tests

The 'Afsluitdijk' is a 32 km enclosure dam which separates the Wadden sea and the Lake IJssel. The dam currently undergoes a major rehabilitation to meet the requirements with regard to water safety. The Dutch Ministry of infrastructure and Water Management (Rijkswaterstaat division) has commissioned Levvel, a consortium of BAM, Van Oord and Rebel, to prepare the design and carry out the reconstruction of the dam including sluices and highway. The project includes reinforcement of the armour layers and wave overtopping reduction. As part of the contract Rijkswaterstaat prescribed the contractor (Levvel) to verify the design with large scale physical model tests (min. 1:3 scale). These tests were carried out in the Delta Flume of Deltares. Prior to the large scale tests, smaller scale tests (1:20) have been carried out to optimize the design with regard to armour stability and wave overtopping. The research described here focuses on the wave overtopping.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/kPga0wVCCIE

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