scholarly journals THE COMPARISON OF EMPIRICAL FORMULAE FOR THE PREDICTION OF MEAN WAVE OVERTOPPING RATE AT ARMORED SLOPED STRUCTURES

2020 ◽  
pp. 22
Author(s):  
Ali Koosheh ◽  
Amir Etemad-Shahidi ◽  
Nick Cartwright ◽  
Rodger Tomlinson ◽  
Shabnam Hosseinzadeh
Keyword(s):  
Detailed Comparison ◽  
Accurate Estimation ◽  
Hydraulic Parameters ◽  
Test Results ◽  
Laboratory Measurements ◽  
Coastal Structures ◽  
Structural Geometry ◽  
Wave Overtopping ◽  
Wave Characteristics ◽  
Potential Impact

Armored sloped structures are generally used to provide the safety of their lee side, i. e. harbours and coastal regions against wave attacks and storm surge. Recently, due to the potential impact of climate change, increasing emphasis has been placed on their hydraulic performance (e.g. Pillai et al. 2019). Thus, accurate estimation of wave overtopping rate, as the hydraulic response of coastal structures, has an important role in design. Wave overtopping is a complex phenomenon and depends on structural geometry and wave characteristics. Hence, empirical formulae are generally used for estimation of mean overtopping rate. These formulae have been derived from laboratory measurements in which the dimensionless measured overtopping rates are correlated with the dimensionless structural and hydraulic parameters through physical arguments. The most well-known formulae for wave overtopping prediction can be found in the Coastal Engineering Manual (2012) and European Overtopping Manual (EurOtop, 2018). The CLASH database as one of the most comprehensive datasets, was initially provided by De Rouck and Geeraerts (2005). This data base was recently updated by including more test results (EurOtop, 2018). However, a detailed comparison of formulae proposed for the estimation of overtopping rates at rubble mound sloped structures is not reported. The present paper aims to evaluate the performance of existing empirical formulae namely EurOtop 2018 (hereafter ET18), Owen (1982), van der Meer and Janssen (1995) (hereafter VMJ) and Jafari and Etemad-Shahidi (2012) (hereafter JES) against EurOtop database (updated CLASH database). The analysis includes structures with different armor types (rock, concrete cubes etc.) with both impermeable and permeable cores, to evaluate the capability of used formulae under different conditions.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/0TL5zFCf6GU

scholarly journals DISTRIBUTION OF INDIVIDUAL WAVE OVERTOPPING VOLUMES ON A SLOPING STRUCTURE WITH A PERMEABLE FORESHORE

2020 ◽  
pp. 54
Author(s):  
Md Salauddin ◽  
John O'Sullivan ◽  
Soroush Abolfathi ◽  
Shudhi Dong ◽  
Jonathan Pearson
Keyword(s):  
Weibull Distribution ◽  
Shape Factor ◽  
Shape Parameter ◽  
Accurate Estimation ◽  
Coastal Structures ◽  
Wave Overtopping ◽  
Scale Parameters ◽  
Distribution Shape ◽  
Individual Wave ◽  
Set Up

Maximum wave overtopping volumes on sea defences are an indicator for identifying risks to people and properties from wave hazards. The probability distribution of individual overtopping volumes can generally be described by a two-parameter Weibull distribution function (shape and scale parameters). Therefore, the reliable prediction of maximum individual wave overtopping volumes at coastal structures relies on an accurate estimation of the shape factor in the Weibull distribution. This study contributes to an improved understanding of the distribution of individual wave overtopping volumes at sloping structures by analysing the wave-by-wave overtopping volumes obtained from physical model experiments on a 1V:2H sloped impermeable structure with a permeable shingle foreshore of slope 1V:20H. Measurements of the permeable shingle foreshore were benchmarked against those from an identical experimental set-up with a smooth impermeable foreshore (1V:20H) of the same geometry. Results from both experimental set-ups were compared to commonly used empirical formulations, underpinned by the assumption that an impermeable foreshore exists in front of the sea structure. The effect on the shape factor in the Weibull distribution of incident wave steepness, relative crest freeboard, probability of overtopping waves and discharge are examined to determine the variation of individual overtopping volumes with respect to these key parameters. A key finding from the study is that no major differences in Weibull distribution shape parameter were observed for the tested impermeable and permeable sloped foreshores. Existing empirical formulae were also shown to predict reasonably well the Weibull distribution shape parameter, b, at sloping structures with both impermeable and permeable slopes.

scholarly journals A LABORATORY STUDY ON WAVE OVERTOPPING AT VERTICAL SEAWALLS WITH A SHINGLE FORESHORE

2018 ◽  
pp. 56 ◽  
Author(s):  
Md Salauddin ◽  
Jonathan Pearson
Keyword(s):  
Laboratory Study ◽  
Vertical Wall ◽  
Empirical Equations ◽  
Laboratory Measurements ◽  
Coastal Structures ◽  
Wave Overtopping ◽  
Empirical Prediction ◽  
Discharge Rates ◽  
Vertical Walls

The existing empirical prediction formulae to determine the wave overtopping characteristics are mainly based on the laboratory measurements with the use of an impermeable foreshore slope in front of the structure. Recently, EurOtop (2016), an updated version of previous overtopping manual has been published with revised empirical equations to estimate mean overtopping discharge rates at plain vertical walls with and without foreshore.As past studies were mostly carried out at vertical seawalls on a fixed impermeable bed, little knowledge is available on the performance of these processes at coastal structures on a permeable shingle beach. This study presents the baseline overtopping characteristics at a plain vertical wall on an impermeable 1:20 foreshore slope, and compares the results with existing empirical predictions (EurOtop, 2016). In this paper, only the results on mean overtopping discharge and mean sediment rate at vertical walls are reported.

IoT Based Bus Tracking System

2021 ◽  
Vol 9 (VI) ◽  
pp. 2889-2893
Author(s):  
Miss Payal W. Paratpure
Keyword(s):  
Tracking System ◽  
Cost Effective ◽  
Raspberry Pi ◽  
Accurate Estimation ◽  
Time Of Arrival ◽  
Test Results ◽  
Cloud Server ◽  
Bus Operator ◽  
Gps Device

Tracking of public bus location requires a GPS device to be installed, and lots of bus operators in developing countries don't have such an answer in situ to supply an accurate estimation of bus time of arrival (ETA). Without ETA information, it's very difficult for the overall public to plan their journey effectively. In this paper, implementation of an innovative IOT solution to trace the real time location of buses without requiring the deployment of a GPS device is discussed. It uses Bluetooth Low Energy (BLE) proximity beacon to trace the journey of a bus by deploying an Estimate location beacon on the bus. BLE detection devices (Raspberry Pi 4) are installed at selected bus stops along the path to detect the arrival of buses. Once detected, the situation of the bus is submitted to a cloud server to compute the bus ETAs. A field trial is currently being conducted in Johor, Malaysia together with an area bus operator on one single path. Our test results showed that the detection of BLE beacons is extremely accurate and it's feasible to trace the situation of buses without employing a GPS device during a cost-effective way.

scholarly journals IRREGULAR WAVE OVERTOPPING RATES

1984 ◽  
Vol 1 (19) ◽  
pp. 22 ◽  
Author(s):  
Scott L. Douglass
Keyword(s):  
Shallow Water ◽  
Shore Protection ◽  
Coastal Structures ◽  
Wave Overtopping ◽  
Manual Method ◽  
Irregular Wave ◽  
Order Of Magnitude

Methods for estimating wave overtopping of coastal structures are reviewed and compared with the very limited available data and with each other. The different methods yield results which can vary more than an order-of-magnitude. For vertical seawalls, the U. S. Army Engineer Shore Protection Manual method estimates more overtopping than Goda's method except in very shallow water. For sloped structures, the Shore Protection Manual method usually estimates less overtopping than Battjes' method and Owen's method. However, data for adequately evaluating how well these methods predict overtopping has not been published.

scholarly journals ABOUT SOME UNCERTAINTIES IN THE PHYSICAL AND NUMERICAL MODELING OF WAVE OVERTOPPING OVER COASTAL STRUCTURES

2014 ◽  
Vol 1 (34) ◽  
pp. 71 ◽  
Author(s):  
Alessandro Romano ◽  
Hannah Elisabeth Williams ◽  
Giorgio Bellotti ◽  
Riccardo Briganti ◽  
Nicholas Dodd ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Coastal Structures ◽  
Wave Overtopping

scholarly journals Extraction and Filter Algorithm of Roll Angular Rate for High Spinning Projectiles

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Hui Zhao ◽  
Zhong Su ◽  
Fuchao Liu ◽  
Chao Li ◽  
Qing Li ◽  
...  
Keyword(s):  
Measurement Problem ◽  
Frequency Estimation ◽  
Angular Rate ◽  
Estimation Accuracy ◽  
Signal Frequency ◽  
Average Error ◽  
Accurate Estimation ◽  
Test Results ◽  
Narrowband Signal ◽  
Spinning Projectile

The accurate measurement of roll angular rate for high spinning projectile has long been a challenging problem. Aiming to obtain the accurate roll angular rate of high spinning projectile, a novel extraction and filter algorithm, BSCZT-KF, is proposed in this paper. Firstly, a compound angular motion model of high spinning projectile is established. According to the model, we translate the roll angular rate measurement problem into a frequency estimation problem. Then the improved CZT algorithm, BSCZT, was employed to realize an accurate estimation of the narrowband signal frequency. Combined with the peak detection method, the BSCZT-KF algorithm is presented to further enhance the frequency estimation accuracy and the real-time performance. Finally, two sets of actual flight tests were conducted to verify the effectiveness and accuracy of the algorithm. The test results show that the average error of estimated roll angular rate is about 0.095% of the maximum of roll angular rate. Compared with the existing methods, the BSCZT-KF has the highest frequency estimation accuracy for narrowband signal.

scholarly journals VERTICAL SEA WALL CREST MODIFICATIONS FOR OVERTOPPING

2018 ◽  
pp. 71
Author(s):  
Dogan Kisacik ◽  
Gulizar Ozyurt Tarakcioglu ◽  
Cuneyt Baykal ◽  
Gokhan Kaboglu
Keyword(s):  
Urban Areas ◽  
Vertical Wall ◽  
Breaking Wave ◽  
Limited Information ◽  
Coastal Structures ◽  
Wave Overtopping ◽  
Wave Basin ◽  
First Results ◽  
Set Up ◽  
Sea Wall

Crest modifications such as a storm wall, parapet or a bullnose are widely used to reduce the wave overtopping over coastal structures where spatial and visual demands restrict the crest heights, especially in urban areas. Although reduction factors of these modifications have been studied for sloped structures in EurOtop Manual (2016), there is limited information regarding the vertical structures. This paper presents the experimental set-up and first results of wave overtopping tests for a vertical wall with several different super structure types: a) seaward storm wall, b) sloping promenade, c) landward storm wall, d) stilling wave basin (SWB), e) seaward storm wall with parapet, f) landward storm wall on the horizontal promenade with parapet, g) landward storm wall with parapet, h) stilling wave basin (SWB) with parapet, under breaking wave conditions. The SWB is made up of a seaward storm wall (may be a double shifted rows) , a sloping promenade (basin) and a landward storm wall. The seaward storm wall is partially permeable to allow the evacuation of the water in the basin.

MECHANISM AND COUNTERMEASURES OF WAVE OVERTOPPING FOR LONG-PERIOD SWELL IN COMPLEX BATHYMETRY

2012 ◽  
Vol 1 (33) ◽  
pp. 45
Author(s):  
Hiroaki Kashima ◽  
Katsuya Hirayama
Keyword(s):  
Deep Water ◽  
Wave Energy ◽  
Spatial Relationship ◽  
Wave Transformation ◽  
Wave Overtopping ◽  
Long Period ◽  
Wave Characteristics ◽  
Water Region ◽  
Wave Heights ◽  
Shallow Water Region

Recently, coastal disasters due to long-period swells induced by heavy storms and catastrophic typhoons have increased at Japanese coasts and harbors. Long-period swells are more susceptible to the bottom bathymetry of the offshore deep water region and their wave heights locally increase due to the concentration of wave energy caused by the complex bottom bathymetry in the relatively shallow water region. In addition, the wave overtopping rate may increase due to the long waves in front of the seawall induced by the long-period swells. However, the spatial relationship between wave characteristics and wave overtopping discharges in the complex bathymetry are not well known owing to a lack of detailed measurements. In this study, model experiments were conducted by using a large basin to investigate the spatial characteristics of wave transformation and wave overtopping focusing on the heavy wave overtopping damages caused by the arrivals of long-period swells at the Shimoniikawa Coast in 2008. Effective countermeasures against wave overtopping are also discussed based on their characteristics.

Wave overtopping at coastal structures: prediction tools and related hazard analysis

2007 ◽  
Vol 15 (16) ◽  
pp. 1514-1521 ◽  
Author(s):  
J. Geeraerts ◽  
P. Troch ◽  
J. De Rouck ◽  
H. Verhaeghe ◽  
J.J. Bouma
Keyword(s):  
Hazard Analysis ◽  
Coastal Structures ◽  
Wave Overtopping ◽  
Prediction Tools

scholarly journals Complete Proceedings - Single PDF Download

1988 ◽  
Vol 1 (21) ◽  
Author(s):  
Billy L. Edge
Keyword(s):  
Civil Engineer ◽  
Case Studies ◽  
Wind Waves ◽  
Coastal Engineering ◽  
Coastal Processes ◽  
Ship Motions ◽  
Coastal Structures ◽  
Wave Characteristics ◽  
The Individual ◽  
Engineering Projects

This book contains over 220 papers presented at the 21st International Conference on Coastal Engineering. The book is divided into six parts: theoretical and observed wave characteristics; coastal processes and sediment transport; coastal structures and related problems; coastal, estuarine and environmental problems; case studies; and ship motions. The individual papers include such topics as the effects of wind, waves, storms and currents, erosion, sedimentation, and beach nourishment. Special emphasis is given to case studies of completed engineering projects. With the inclusion of both the theoretical and the practical, these papers provide the civil engineer with a broad range of information on coastal engineering.

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