scholarly journals Debris flow risk mitigation by the means of rigid and flexible barriers – experimental tests and impact analysis

2012 ◽  
Vol 12 (5) ◽  
pp. 1693-1699 ◽  
Author(s):  
L. Canelli ◽  
A. M. Ferrero ◽  
M. Migliazza ◽  
A. Segalini
Keyword(s):  
Debris Flow ◽  
Impact Analysis ◽  
Risk Mitigation ◽  
Experimental Tests ◽  
Detailed Knowledge ◽  
Different Types ◽  
Flexible Barriers ◽  
The Impact ◽  
Destructive Potential

Abstract. The impact of a debris flow on a structure can have disastrous effects because of the enormous destructive potential of this type of phenomenon. Although the introduction of risk mitigation structures such as the Sabo Dam, the filter dam and more recently flexible barriers is usual, there are very few methods that are universally recognized for the safe design of such structures. This study presents the results of experimental tests, conducted with the use of a specifically created flume, in order to obtain detailed knowledge of the mechanical aspects, and to analyze the dynamics of the impact of a debris flow on different types of structures. The analyses of the tests, together with the calculation of the thrust caused by the flow, have made it possible to analyze the dynamics of the impact, which has shown differing effects, on the basis of the type of barrier that has been installed.

The Effects of Upstream Flexible Barrier on the Debris Flow Entrainment and Impact Dynamics on a Terminal Barrier

2021 ◽  
Author(s):  
Hervé Vicari ◽  
C.W.W. Ng ◽  
Steinar Nordal ◽  
Vikas Thakur ◽  
W.A. Roanga K. De Silva ◽  
...  
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Impact Force ◽  
Dynamic Pressure ◽  
Pressure Coefficient ◽  
Flexible Barrier ◽  
Impact Forces ◽  
Flexible Barriers ◽  
The Impact ◽  
Bed Entrainment

The destructive nature of debris flows is mainly caused by flow bulking from entrainment of an erodible channel bed. To arrest these flows, multiple flexible barriers are commonly installed along the predicted flow path. Despite the importance of an erodible bed, its effects are generally ignored when designing barriers. In this study, three unique experiments were carried out in a 28 m-long flume to investigate the impact of a debris flow on both single and dual flexible barriers installed in a channel with a 6 m-long erodible soil bed. Initial debris volumes of 2.5 m<sup>3</sup> and 6 m<sup>3</sup> were modelled. For the test setting adopted, a small upstream flexible barrier before the erodible bed separates the flow into several surges via overflow. The smaller surges reduce bed entrainment by 70% and impact force on the terminal barrier by 94% compared to the case without an upstream flexible barrier. However, debris overflowing the deformed flexible upstream barrier induces a centrifugal force that results in a dynamic pressure coefficient that is up to 2.2 times higher than those recommended in guidelines. This suggests that although compact upstream flexible barriers can be effective for controlling bed entrainment, they should be carefully designed to withstand higher impact forces.

scholarly journals Experimental tests of the impact of selected parameters on the indentation rolling resistances

2018 ◽  
Vol 29 ◽  
pp. 00002 ◽  
Author(s):  
Dariusz Woźniak ◽  
Lech Gładysiewicz ◽  
Martyna Konieczna
Keyword(s):  
Main Part ◽  
Rolling Resistance ◽  
Experimental Tests ◽  
Conveyor Belt ◽  
Significant Component ◽  
Different Types ◽  
Indentation Rolling Resistance ◽  
Belt Conveyors ◽  
The Impact

Belt conveyors are main part of transporting systems in mines and in many other branches of industry. During conveyor belt works different types of resistances are generated. Indentation rolling resistance is the most significant component of the resistances from the perspective of energy losses and it cause the biggest costs as well. According to latest state of analyses and measurements it is well known that theoretical rolling resistance were underestimated in comparison with the measured in-situ one. In this paper new method for determination indentation rolling resistance is presented. The authors compared theoretically and experimentally established damping factors. The relation between these two values enabled to obtain more precise equation for damping function. This function is one of the most important component in calculation of the rolling resistance. In new theoretical model value of rolling resistance is nearly twice higher than this used so far.

Field evaluation of the performance of different irrigation emitter types using treated wastewater

2015 ◽  
Vol 50 (3) ◽  
pp. 240-251 ◽  
Author(s):  
Naji K. Al-Mefleh ◽  
Ibrahim Bashabsheh ◽  
Samer Talozi ◽  
Taha A. Al-Issa
Keyword(s):  
Fresh Water ◽  
Coefficient Of Variation ◽  
Chemical Properties ◽  
Experimental Tests ◽  
Field Evaluation ◽  
Treated Wastewater ◽  
Uniformity Coefficient ◽  
Different Types ◽  
The Impact ◽  
Emitter Discharge

Experimental tests are carried out to evaluate the impact of treated wastewater (TWW) on the discharge of five different types of emitters which are commonly used. Two water qualities, fresh water (FW) and treated wastewater, and five types of emitters, GR, Nein (NE), Edin (ED), Corona (CO), and Rain Bird (RB) are tested. The values of chemical properties for FW show mostly low clogging potential on emitter performance. The clogging potential for TWW varied from low to medium. The exception was for pH where there was severe clogging potential for both water types. The performance of emitters was tested by measuring the emitter discharge and estimating the average emitter discharge (Qavg), coefficient of variation (CV), emission uniformity coefficient (EU), and Christiansen uniformity coefficient (CU). The average discharges for different types of emitters were analyzed and compared at P ≤ 0.05. The CO and RB emitter types did not show any signs of clogging whereas the GR, NE, and ED emitter types showed signs of clogging. The results of CV, EU, and CU values showed that the performances of emitter types GR, NE, ED were classified as low or moderate clogging potential. In contrast, the CO and RB emitters were classified as moderate or high clogging potential.

Surface Structure of Asphalt Pavement Non-Nuclear Density Gauge Density Test Results the Impact Analysis

2012 ◽  
Vol 204-208 ◽  
pp. 1937-1940
Author(s):  
Hai Zhao
Keyword(s):  
Surface Texture ◽  
Impact Analysis ◽  
Asphalt Mixture ◽  
Nuclear Density ◽  
Test Results ◽  
Different Types ◽  
Surface Sand ◽  
Nuclear Density Gauge ◽  
Influence Degree ◽  
The Impact

In order to study the influence degree of the different asphalt mixture surface texture structure to the test of Non-nuclear density gauge(Pave Tracker™ Plus 2701-B). This thesis utilized non-nuclear density gauge and surface sanding method for different types of mixtures were compacted density and surface texture depth test. The results showed that: It can produce certain effect, and with it the inhomogeneity of the increases. This is mainly about mixture gradation type, among them SMA-13 affect the minimum, AC-20 take second place, ATB-25 maximum. However, using the surface sand can effective to reduce its impact. So, recommendations for ATB-25 type mixture can be used to detect the surface sand, and the SMA-13 and AC-20 are not used.

scholarly journals The Impact of Various Fuels on Particulate Emissions for a Compression Ignition Engine Equipped with a Diesel Particulate Filter

2021 ◽  
Vol 44 (4) ◽  
pp. 48-53
Author(s):  
Bogdan Manolin JURCHIȘ
Keyword(s):  
Engine Performance ◽  
Experimental Tests ◽  
Fuel Mixture ◽  
Particulate Filter ◽  
Particulate Emissions ◽  
Compression Ignition Engine ◽  
Smoke Emission ◽  
Particulate Filters ◽  
Different Types ◽  
The Impact

The aim of this research was to highlight the impact of using different types of fuels on particulate emissions and also on the operation on particulate filters on diesel engines. For all the results obtained from the experimental tests, comparative studies were performed to find the optimal fuel mixture that can be used in order to obtain the optimal performance of the particle filter, without affecting the engine performance. Following the initial tests performed without DPF, the case with the highest smoke emission value (2000 1/min) was identified. For this case, continuous measurement tests were then performed. For this reason, a more detailed analysis was made only for this case.

scholarly journals Finite element analysis for rockfall and debris flow mitigation works

2019 ◽  
Vol 56 (9) ◽  
pp. 1225-1250 ◽  
Author(s):  
Julian S.H. Kwan ◽  
Eric H.Y. Sze ◽  
Carlos Lam
Keyword(s):  
Finite Element ◽  
Debris Flow ◽  
Numerical Models ◽  
Pressure Coefficient ◽  
Hydrodynamic Pressure ◽  
Ethylene Vinyl Acetate ◽  
Element Analysis ◽  
Current Design ◽  
Flexible Barriers ◽  
The Impact

Landslide risks arising from boulder falls and debris flows are commonly mitigated using rigid and flexible barriers. Debris–barrier interaction is a complicated process, so current design methods rely on the use of the pseudo-static force approach. In addition to physical testing, numerical simulations can be used to provide insight into the impact mechanism. This paper presents the applications of numerical models to simulate rigid and flexible barriers subjected to rockfall and debris-flow impacts, respectively. For rigid barriers, rock-filled gabions, a recycled glass cullet, cellular glass aggregates, and ethylene-vinyl acetate (EVA) foam were assessed for their performance as cushioning materials. From the results, empirical equations were established for predicting the boulder impact forces and penetration into the cushion layer. Amongst the materials considered in this study, rock-filled gabions appear to be the most promising for use in practice. For flexible barriers, finite-element models, calibrated using documented case histories, were developed to simulate the debris–barrier interaction. The models were used to investigate the barriers’ behavior under debris impacts from both force and energy perspectives. From the results, the hydrodynamic pressure coefficient was found to be lower than the current recommended value whilst only a small amount of debris energy was transferred to the barrier.

Quota Women Are Threatening to Men

2017 ◽  
Vol 76 (3) ◽  
pp. 107-116 ◽  
Author(s):  
Klea Faniko ◽  
Till Burckhardt ◽  
Oriane Sarrasin ◽  
Fabio Lorenzi-Cioldi ◽  
Siri Øyslebø Sørensen ◽  
...  
Keyword(s):  
Decision Making ◽  
Organizational Performance ◽  
Gender Stereotypes ◽  
Perceived Threat ◽  
Preferential Treatment ◽  
Public Sector Employees ◽  
Different Types ◽  
Low Levels ◽  
Women In Decision Making ◽  
The Impact

Abstract. Two studies carried out among Albanian public-sector employees examined the impact of different types of affirmative action policies (AAPs) on (counter)stereotypical perceptions of women in decision-making positions. Study 1 (N = 178) revealed that participants – especially women – perceived women in decision-making positions as more masculine (i.e., agentic) than feminine (i.e., communal). Study 2 (N = 239) showed that different types of AA had different effects on the attribution of gender stereotypes to AAP beneficiaries: Women benefiting from a quota policy were perceived as being more communal than agentic, while those benefiting from weak preferential treatment were perceived as being more agentic than communal. Furthermore, we examined how the belief that AAPs threaten men’s access to decision-making positions influenced the attribution of these traits to AAP beneficiaries. The results showed that men who reported high levels of perceived threat, as compared to men who reported low levels of perceived threat, attributed more communal than agentic traits to the beneficiaries of quotas. These findings suggest that AAPs may have created a backlash against its beneficiaries by emphasizing gender-stereotypical or counterstereotypical traits. Thus, the framing of AAPs, for instance, as a matter of enhancing organizational performance, in the process of policy making and implementation, may be a crucial tool to countering potential backlash.

The Impact of a Potential Public/Private Initiative on a Defined Region of the South Suburban Chicago Metropolitan Area

2019 ◽  
pp. 14-32
Keyword(s):  
Supply Chain ◽  
Economic Impact ◽  
Impact Analysis ◽  
Census Data ◽  
Economic Benefits ◽  
Local Economy ◽  
Market Area ◽  
State And Local ◽  
The University ◽  
The Impact

The university is considered one of the engines of growth in a local economy or its market area, since its direct contributions consist of 1) employment of faculty and staff, 2) services to students, and supply chain links vendors, all of which define the University’s Market area. Indirect contributions consist of those agents associated with the university in terms of community and civic events. Each of these activities represent economic benefits to their host communities and can be classified as the economic impact a university has on its local economy and whose spatial market area includes each of the above agents. In addition are the critical links to the University, which can be considered part of its Demand and Supply chain. This paper contributes to the field of Public/Private Impact Analysis, which is used to substantiate the social and economic benefits of cooperating for economic resources. We use Census data on Output of Goods and Services, Labor Income on Salaries, Wages and Benefits, Indirect State and Local Taxes, Property Tax Revenue, Population, and Inter-Industry to measure economic impact (Implan, 2016).

Impact Analysis of the Mechanization Program for Tribal Paddy Farmers of Goa

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
MATHALA JULIET GUPTA ◽  
ASHISH M. PITRE ◽  
SUMATI CHAVAN PANDURNAG ◽  
SALONI SALIL VANJARI
Keyword(s):  
Impact Analysis ◽  
Field Capacity ◽  
Significant Saving ◽  
Manual Methods ◽  
Paddy Farmers ◽  
The Impact ◽  
And Training

This paper assessed the impact of the mechanization of the 8 tribal paddy farmers’ groups of Goa benefited in the year 2011 through the Tribal sub-plan program of ICAR-CCARI through results of surveys conducted in 2012 and 2015. Shift to mechanization among beneficiaries was significant in power tillers (64-100%) but less in power reapers(0-91%). Also significant saving in manpower (Power tillers:33.3% to 60%, power reapers: 33.3% to 83.3%), , time (field capacity increased (power tillers : 41.7% to141%, power reapers :58.1% to 912.8%) and cost(power tillers :44.7% to 59.1%, power reapers : 57.8% to 82.9%) was reportedthrough the use of equipment as compared to desi plough or manual methods of harvesting. Some constraints like lack of access roads and training in use and maintenance of the equipment were reported by the beneficiary farmers.

Situational Breakdowns

2019 ◽  
Author(s):  
Anne Nassauer
Keyword(s):  
United States ◽  
Large Scale ◽  
Contextual Factors ◽  
The United States ◽  
Social Outcomes ◽  
Dynamic Processes ◽  
Collective Decisions ◽  
Different Types ◽  
The Impact

This book provides an account of how and why routine interactions break down and how such situational breakdowns lead to protest violence and other types of surprising social outcomes. It takes a close-up look at the dynamic processes of how situations unfold and compares their role to that of motivations, strategies, and other contextual factors. The book discusses factors that can draw us into violent situations and describes how and why we make uncommon individual and collective decisions. Covering different types of surprise outcomes from protest marches and uprisings turning violent to robbers failing to rob a store at gunpoint, it shows how unfolding situations can override our motivations and strategies and how emotions and culture, as well as rational thinking, still play a part in these events. The first chapters study protest violence in Germany and the United States from 1960 until 2010, taking a detailed look at what happens between the start of a protest and the eruption of violence or its peaceful conclusion. They compare the impact of such dynamics to the role of police strategies and culture, protesters’ claims and violent motivations, the black bloc and agents provocateurs. The analysis shows how violence is triggered, what determines its intensity, and which measures can avoid its outbreak. The book explores whether we find similar situational patterns leading to surprising outcomes in other types of small- and large-scale events: uprisings turning violent, such as Ferguson in 2014 and Baltimore in 2015, and failed armed store robberies.

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