Local/global homogenization (LGH) applied to sound reflection from a flexible barrier with impedance discontinuities

2002 ◽  
Vol 111 (5) ◽  
pp. 2473
Author(s):  
Donald Bliss ◽  
Linda Franzoni ◽  
Pavel Danilov
Keyword(s):  
Flexible Barrier ◽  
Sound Reflection

Debris flow impact on a flexible barrier: laboratory flume experiments and force-based mechanical model validation

2021 ◽  
Vol 106 (1) ◽  
pp. 735-756
Author(s):  
R. Brighenti ◽  
L. Spaggiari ◽  
A. Segalini ◽  
R. Savi ◽  
G. Capparelli
Keyword(s):  
Debris Flow ◽  
Model Validation ◽  
Mechanical Model ◽  
Flume Experiments ◽  
Flexible Barrier ◽  
Laboratory Flume

Underwater Sound Reflection from Layered Media

1964 ◽  
Vol 36 (11) ◽  
pp. 2119-2123 ◽  
Author(s):  
G. R. Barnard ◽  
J. L. Bardin ◽  
W. B. Hempkins
Keyword(s):  
Layered Media ◽  
Underwater Sound ◽  
Sound Reflection

Problems of sound reflection in rooms

1975 ◽  
Vol 8 (3) ◽  
pp. 157-172 ◽  
Author(s):  
Zyun-iti Maekawa
Keyword(s):  
Sound Reflection

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 Investigations of the Rockfall Impacts on the Flexible Protective Barriers under Seismic Loading

2021 ◽  
Author(s):  
Ziwei Ge ◽  
Hongyan Liu
Keyword(s):  
Field Test ◽  
Seismic Waves ◽  
Maximum Shear Stress ◽  
Seismic Loading ◽  
Maximum Elongation ◽  
Protective Barrier ◽  
Flexible Barrier ◽  
Novel Approach ◽  
Simulation Results ◽  
Deformation Area

Abstract Rockfall triggered by earthquakes can cause severe infrastructure losses and even fatalities. The flexible protective barrier is an efficient rockfall protection system that has been widely used against rockfall. This studyproposed a novel approach to simulate a field test of rockfall impacting the flexible barrier, and the simulation results showed an excellent match with the field test results. Based on this approach, the seismic loading was applied to the numerical model, and four types of seismic loading were adopted, e.g., non-seismic, x-directional seismic, y-directional seismic, and z-directional seismic. This study aims at investigating the dynamic behavior of the flexible protective barrier under different seismic loading during the rockfall impact process. The following findings can be obtained from the simulation results. First of all, the seismic loading can increase the maximum elongation and decrease the final elongation of the flexible protective barrier comparing to non-seismic loading. Second, the largest deformation area of the protective barrier is at the diagonal position when x-directional seismic loading was applied, which is at the vertical bisector position when y-directional and z-directional seismic loading was applied. Third, the maximum elongation of the protective barrier decreased with the increasing seismic wave period. But in general, the amplitude and period of seismic waves have negligible effects on the elongation, maximum normal stress, and maximum shear stress of the flexible protective barrier.

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