Experimental and Analytical Study of Water-Driven Debris Impact Forces on Structures1

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
H. R. Riggs ◽  
D. T. Cox ◽  
C. J. Naito ◽  
M. H. Kobayashi ◽  
P. Piran Aghl ◽  
...  
Keyword(s):  
Full Scale ◽  
State University ◽  
Large Wave ◽  
Substantial Impact ◽  
Wave Flume ◽  
Shipping Container ◽  
Lehigh University ◽  
Impact Forces ◽  
Utility Pole ◽  
The Impact

Water-driven debris generated during tsunamis and hurricanes can impose substantial impact forces on structures that are often not designed for such loads. This paper presents the design and results of an experimental and analytical program to quantify these potential impact forces. Two types of prototypical debris are considered: a wood log and a shipping container. Full-scale impact tests at Lehigh University (LU) were carried out with a wooden utility pole and a shipping container. The tests were carried out in-air. The purpose of these tests was to provide baseline, full-scale results. Because of size limitations, a 1:5 scale shipping container model was used for in-water tests in the Oregon State University (OSU) large wave flume. These tests were used to quantify the effect of the fluid on the impact forces. Results from both experimental programs are presented and compared with analytical predictions. The predictions are found to be in sufficient agreement such that they can be used for design. A fundamental finding is that the impact forces are dominated by the structural impact, with a secondary effect provided by the fluid. Both forces are quantified in the paper.

Water-Driven Debris Impact Forces on Structures: Experimental and Theoretical Program

2013 ◽  
Author(s):  
H. R. Riggs ◽  
D. T. Cox ◽  
C. J. Naito ◽  
M. H. Kobayashi ◽  
P. Piran Aghl ◽  
...  
Keyword(s):  
Full Scale ◽  
State University ◽  
Large Wave ◽  
Substantial Impact ◽  
Wave Flume ◽  
Shipping Container ◽  
Lehigh University ◽  
Impact Forces ◽  
Theoretical Predictions ◽  
The Impact

Water-driven debris generated during tsunamis and hurricanes can impose substantial impact forces on structures that are often not designed for such loads. This paper presents the design and results of an experimental and theoretical program to quantify these potential impact forces. Two types of prototypical debris are considered: a wood log and a shipping container. Full-scale impact tests at Lehigh University were carried out with a wooden utility pole and a shipping container. The tests were carried out in-air, and were designed to provide baseline, full-scale results. A 1:5 scale shipping container model was used for in-water tests in the Oregon State University large wave flume. These tests were used to quantify the effect of the fluid on the impact forces. Results from both experimental programs are presented and compared with theoretical predictions. The analytical predictions are found to be in sufficient agreement such that they can be used for design. A fundamental takeaway is that the impact forces are dominated by the structural impact, with a secondary affect provided by the fluid. Both forces are quantified in the paper.

scholarly journals FULL SCALE IMPACT TESTS OF AN OVERTOPPING BORE ON A VERTICAL WALL IN THE LARGE WAVE FLUME (GWK) IN HANNOVER

2012 ◽  
Vol 1 (33) ◽  
pp. 62 ◽  
Author(s):  
Julien De Rouck ◽  
Koen Van Doorslaer ◽  
Tom Versluys ◽  
Karunya Ramachandran ◽  
Stefan Schimmels ◽  
...  
Keyword(s):  
Return Period ◽  
Structural Design ◽  
Vertical Wall ◽  
Full Scale ◽  
Impact Loads ◽  
Flow Depth ◽  
Large Wave ◽  
Wave Flume ◽  
Hydraulic Process ◽  
The Impact

To meet up with the requirements of the Flemish Government, the Belgian coastline needs a protection to a storm with a return period of 1000 years. At well-chosen locations, storm walls will be built, and for the structural design of these walls the impact loadings need to be known. Tests have been carried out at full scale in the Grosser Wellen Kanal, to determine the impact loads by overtopping bores. Wave overtopping over the crest of the dike occurs, and the overtopping bore progresses along the horizontal crest of the dike before impacting the storm wall. It is of major importance that such a wall can withstand the impacts. This paper describes the hydraulic process on the crest of the dike, expressed with parameters such as flow depth and flow velocity, and links them to the impact measured on the storm wall. Both pressures and forces are measured, and compared to each other.

Nonlinear and Dissipative Characteristics of a Combined Random-Cnoidal Wave Field

2017 ◽  
Author(s):  
James M. Kaihatu ◽  
John T. Goertz ◽  
Samira Ardani ◽  
Alex Sheremet
Keyword(s):  
Wave Spectrum ◽  
Leading Edge ◽  
Dissipation Function ◽  
Indian Ocean Tsunami ◽  
Random Wave ◽  
Cnoidal Wave ◽  
State University ◽  
Large Wave ◽  
Wave Flume ◽  
Wave Trains

Images of the 2004 Indian Ocean tsunami at landfall shows a leading edge marked by short waves (“fission” waves). These waves appear to be cnoidal in shape and of a temporal and spatial scale in line with the longest swell present in the region, and may interact with the longer waves in the background random wave spectrum. As part of a comprehensive series of experiments, the Large Wave Flume at Oregon State University (USA) was used to generate and measure the properties of cnoidal, random, and combined cnoidal-random wave trains. Both the nonlinear energy transfer characteristics (via bispectral analysis) and dissipation characteristics (via a proxy dissipation function) are studied for all generated wave conditions. It is generally determined that the characteristics of the cnoidal wave dominate the combined cnoidal-random wave signals if the energy of the cnoidal wave is at least equal to that of the random wave.

EVALUATION OF THE OPERATIONAL WEAR OF THE SANDVIK CV117 CENTRIFUGAL CRUSHER

Tribologia ◽  
2020 ◽  
Vol 289 (1) ◽  
pp. 31-39
Author(s):  
Dominika GRYGIER
Keyword(s):  
Kinetic Energy ◽  
Structural Properties ◽  
Direct Contact ◽  
Operating Time ◽  
Full Scale ◽  
Impact Forces ◽  
The Impact ◽  
Macroscopic Analysis

The purpose of the study described in the work was to evaluate the operating wear of the SANDVIK CV117 centrifugal crusher working in the Melaphyre mine in Grzędy. The research was carried out on work elements, such as the lining assembly, rotor tips, shredder hammers, the directional bushing, and the distributor divider. All components had direct contact with the aggregate, and their operating time was about 1150 hours. The studies included a mine full scale observation, macroscopic analysis of the elements, and an assessment of the impact of exploitation on selected structural properties of the elements material. On the basis of the carried out analyses, it was concluded that the major problem faced by all the tested components is the simultaneous interaction of high friction and impact forces resulting from the kinetic energy of the accelerated grains of the material acquired from the rotor during operation of the crusher.

Experimental Investigation of Tsunami Bore Forces on Vertical Walls

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
I. N. Robertson ◽  
K. Paczkowski ◽  
H. R. Riggs ◽  
A. Mohamed
Keyword(s):  
Vertical Wall ◽  
State University ◽  
Flat Bottom ◽  
Large Wave ◽  
Wave Flume ◽  
Pressure Distributions ◽  
Vertical Walls ◽  
Series Of Experiments ◽  
Maximum Impact Force ◽  
Sloping Beach

A series of experiments have been carried out in the large wave flume (LWF) at Oregon State University to quantify tsunami bore forces on structures. These tests included “offshore” solitary waves, with heights up to 1.3 m, that traveled over a flat bottom, up a sloping beach, and breaking onto a flat reef. Standing water depths on the reef varied from 0.05 m to 0.3 m. Resulting bores on the reef measured up to approximately 0.8 m. After propagating along the reef, the bores struck a vertical wall. The resulting forces and pressures on the wall were measured. The test setup in the LWF is described, and the experimental results are reported. The results include forces and pressure distributions. Results show that the bores propagated with a Froude number of approximately 2 and that the forces follow Froude scaling. Finally, a design formula for the maximum impact force is given. The formula is shown to be an improvement over existing formulas found in the literature.

Impact of Biomechanics Research on Society

2012 ◽  
Vol 1 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Ronald F. Zernicke ◽  
Grant C. Goulet ◽  
Peter R. Cavanagh ◽  
Benno M. Nigg ◽  
James A. Ashton-Miller ◽  
...  
Keyword(s):  
Visual Arts ◽  
Pelvic Floor Dysfunction ◽  
Osteoporotic Fractures ◽  
Human Locomotion ◽  
Skeletal Growth ◽  
Musculoskeletal Health ◽  
Substantial Impact ◽  
The Past ◽  
Impact Forces ◽  
The Impact

As a field, biomechanics comprises research from the molecular and cellular levels, to tissues, to organs, to organisms and their movements. In the past 50 years, the impact of biomechanics research on society has been amplified dramatically. Here, we provide five brief summaries of exemplar biomechanics results that have had substantial impact on health and our society, namely 1) spaceflight and microgravitational effects on musculoskeletal health; 2) impact forces, soft tissue vibrations, and skeletal muscle tuning affecting human locomotion; 3) childbirth mechanics, injuries, and pelvic floor dysfunction; 4) prescriptive physical activity in childhood to enhance skeletal growth and development to prevent osteoporotic fractures in adulthood and aging; and 5) creative innovations in technology that have transformed the visual arts and entertainment.

scholarly journals WAVE LOADS ON EXPOSED JETTIES: DESCRIPTION OF LARGE SCALE EXPERIMENTS AND PRELIMINARY RESULTS

2011 ◽  
Vol 1 (32) ◽  
pp. 18 ◽  
Author(s):  
Luca Martinelli ◽  
Alberto Lamberti ◽  
Maria Gabriella Gaeta ◽  
Matteo Tirindelli ◽  
John Alderson ◽  
...  
Keyword(s):  
Large Scale ◽  
Research Team ◽  
Scale Effects ◽  
Wave Loads ◽  
Large Wave ◽  
Preliminary Results ◽  
Wave Flume ◽  
Air Content ◽  
Wave Induced ◽  
The Impact

The large scale experiments described in this paper were carried out at the Large Wave Flume (GWK, Große Wellenkanal) in Hanover (Germany). The research team included Universities of Bologna (IT), Edinburgh (UK), Southampton (UK), Plymouth (UK), HR Wallingford (UK) and Coast & Harbor Engineering Inc (USA). Wave-induced loads on close-to-prototype scale jetties were measured, with particular attention to scale effects due to air content in water. The aim of the paper is to present the tests, describe the impact process and give preliminary results concerning uplift loads.

The Impact of Competitive Quasi-Market on Service Delivery in Benue State University, Makurdi Nigeria

GIS Business ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 85-98
Author(s):  
Idoko Peter
Keyword(s):  
Service Delivery ◽  
A Priori ◽  
Least Square ◽  
Secondary Source ◽  
State University ◽  
Ordinary Least Square ◽  
Negative Effect ◽  
The Impact ◽  
The Relationship

This research the impact of competitive quasi market on service delivery in Benue State University, Makurdi Nigeria. Both primary and secondary source of data and information were used for the study and questionnaire was used to extract information from the purposively selected respondents. The population for this study is one hundred and seventy three (173) administrative staff of Benue State University selected at random. The statistical tools employed was the classical ordinary least square (OLS) and the probability value of the estimates was used to tests hypotheses of the study. The result of the study indicates that a positive relationship exist between Competitive quasi marketing in Benue State University, Makurdi Nigeria (CQM) and Transparency in the service delivery (TRSP) and the relationship is statistically significant (p<0.05). Competitive quasi marketing (CQM) has a negative effect on Observe Competence in Benue State University, Makurdi Nigeria (OBCP) and the relationship is not statistically significant (p>0.05). Competitive quasi marketing (CQM) has a positive effect on Innovation in Benue State University, Makurdi Nigeria (INVO) and the relationship is statistically significant (p<0.05) and in line with a priori expectation. This means that a unit increases in Competitive quasi marketing (CQM) will result to a corresponding increase in innovation in Benue State University, Makurdi Nigeria (INVO) by a margin of 22.5%. It was concluded that government monopoly in the provision of certain types of services has greatly affected the quality of service experience in the institution. It was recommended among others that the stakeholders in the market has to be transparent so that the system will be productive to serve the society effectively

The Digital Divide and K-12 Student Computer Use

10.28945/2926 ◽  
2005 ◽  
Author(s):  
James N. Morgan ◽  
Craig A. VanLengen
Keyword(s):  
Digital Divide ◽  
Computer Use ◽  
Census Data ◽  
Internet Access ◽  
Demographic Characteristics ◽  
The Internet ◽  
Substantial Impact ◽  
Limited Basis ◽  
K 12 ◽  
The Impact

The divide between those who have computer and Internet access and those who do not appears to be narrowing, however overall statistics may be misleading. Measures of computer availability in schools often include cases where computers are only available for administration or are available only on a very limited basis (Gootman, 2004). Access to a computer and the Internet outside of school helps to reinforce student learning and emphasize the importance of using technology. Recent U.S. statistics indicate that ethnic background and other demographic characteristics still have substantial impact on the availability and use of computers by students outside of the classroom. This paper examines recent census data to determine the impact of the household on student computer use outside of the classroom. Encouragingly, the findings of this study suggest that use of a computer at school substantially increases the chance that a student will use a computer outside of class. Additionally, this study suggests that computer use outside of the classroom is positively and significantly impacted by being in a household with adults who either use a computer at work or work in an industry where computers are extensively used.

Incentivizing Peace

2018 ◽  
Author(s):  
Jaroslav Tir ◽  
Johannes Karreth
Keyword(s):  
World War Ii ◽  
Civil Wars ◽  
Full Scale ◽  
Armed Conflicts ◽  
East Timor ◽  
Low Level ◽  
Self Interest ◽  
The World ◽  
Economic Tools ◽  
The Impact

Civil wars are one of the most pressing problems facing the world. Common approaches such as mediation, intervention, and peacekeeping have produced some results in managing ongoing civil wars, but they fall short in preventing civil wars in the first place. This book argues for considering civil wars from a developmental perspective to identify steps to assure that nascent, low-level armed conflicts do not escalate to full-scale civil wars. We show that highly structured intergovernmental organizations (IGOs, e.g. the World Bank or IMF) are particularly well positioned to engage in civil war prevention. Such organizations have both an enduring self-interest in member-state peace and stability and potent (economic) tools to incentivize peaceful conflict resolution. The book advances the hypothesis that countries that belong to a larger number of highly structured IGOs face a significantly lower risk that emerging low-level armed conflicts on their territories will escalate to full-scale civil wars. Systematic analyses of over 260 low-level armed conflicts that have occurred around the globe since World War II provide consistent and robust support for this hypothesis. The impact of a greater number of memberships in highly structured IGOs is substantial, cutting the risk of escalation by over one-half. Case evidence from Indonesia’s East Timor conflict, Ivory Coast’s post-2010 election crisis, and from the early stages of the conflict in Syria in 2011 provide additional evidence that memberships in highly structured IGOs are indeed key to understanding why some low-level armed conflicts escalate to civil wars and others do not.

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