scholarly journals Insights from the particle impact model into the high frequency seismic signature of debris flows

2020 ◽  
Author(s):  
Zhen Zhang ◽  
Fabian Walter ◽  
Brian W. McArdell ◽  
Michaela Wenner ◽  
Małgorzata Chmiel ◽  
...  
Keyword(s):  
High Frequency ◽  
Debris Flows ◽  
Particle Impact ◽  
Impact Model ◽  
Seismic Signature

Analyzing bulk flow characteristics of debris flows using their high frequency seismic signature

2021 ◽  
Author(s):  
Zhen Zhang ◽  
Fabian Walter ◽  
Brian W. McArdell ◽  
Tjalling Haas ◽  
Michaela Wenner ◽  
...  
Keyword(s):  
High Frequency ◽  
Debris Flows ◽  
Flow Characteristics ◽  
Bulk Flow ◽  
Seismic Signature

scholarly journals Analysis of the ground vibration generated by debris flows and other torrential processes at the Rebaixader monitoring site (Central Pyrenees, Spain)

2014 ◽  
Vol 14 (4) ◽  
pp. 929-943 ◽  
Author(s):  
C. Abancó ◽  
M. Hürlimann ◽  
J. Moya
Keyword(s):  
High Frequency ◽  
Debris Flows ◽  
Low Frequency ◽  
Ground Vibration ◽  
Monitoring Site ◽  
Velocity Signal ◽  
Vibration Sensors ◽  
Definition Of ◽  
Flow Detection ◽  
Central Pyrenees

Abstract. Monitoring of debris flows using ground vibration sensors has increased in the last two decades. However, the correct interpretation of the signals still presents ambiguity. In the Rebaixader monitoring site (Central Pyrenees, Spain) two different ground vibration stations are installed. At the first station the ground velocity signal is transformed into an impulses-per-second signal (low frequency, 1 Hz). The analysis of the data recorded at this station show that the shape of the impulses signal is one of the key parameters to describe the evolution of the event. At the second station the ground velocity signal is directly recorded at high frequency (250 Hz). The results achieved at this station show that the differences in time series and spectral analysis are helpful to describe the temporal evolution of the events. In addition, some general outcomes were obtained: the attenuation of the signal with the distance has been identified as linear to exponential; and the assembly of the geophones to the terrain has an important effect on the amplification of the signal. All these results highlight that the definition of ground vibration thresholds for debris-flow detection or warning purposes is a difficult task; and that influence of site-specific conditions is notable.

scholarly journals Landslides distribution at tributaries with different evolution stages in Jiangjia Gully, southwestern China

2019 ◽  
Author(s):  
Xia Fei Tian ◽  
Yong Li ◽  
Quan Yan Tian ◽  
Feng Huan Su
Keyword(s):  
High Frequency ◽  
Debris Flows ◽  
Satellite Image ◽  
Flow Regimes ◽  
Southwestern China ◽  
Grid Cells ◽  
Jiangjia Gully ◽  
Material Sources ◽  
Main Material

Abstract. Jiangjia Gully (JJG) is known for its high frequency and variety of debris flows, especially the intermittent surges of various flow regimes and materials. Observation indicates that the surges come from various tributaries with different landslides activities. In this study, 81 tributaries of JJG are taken from DEM with 10 m grid cells, and the hypsometric curves are used to characterize their evolution stages; five stages are identified by the evolution index (EI, the integral of the hypsometric curves) and most tributaries are in relative youth stage with EI between 0.5 and 0.6. Then 908 landslides are interpreted from Quickbird satellite image of 0.61 m resolution, and it is found that LD (LD = landslides number in a tributary/the tributary area) increases exponentially with EI, while LAp (LAp = landslides area in a tributary/the tributary area) fluctuates with EI, meaning that landslides are inclined to occur in tributaries with EI between 0.5 and 0.6, and thus these tributaries are the main material sources supplying for debris flows.

Finite element analysis on the dynamic erosion process using multiple-particle impact model

2017 ◽  
Vol 315 ◽  
pp. 163-170 ◽  
Author(s):  
Chao Zheng ◽  
Yonghong Liu ◽  
Cheng Chen ◽  
Jie Qin ◽  
Shihong Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Particle Impact ◽  
Impact Model ◽  
Erosion Process ◽  
Element Analysis ◽  
Multiple Particle

scholarly journals A physical model of the high‐frequency seismic signal generated by debris flows

2019 ◽  
Vol 44 (13) ◽  
pp. 2529-2543 ◽  
Author(s):  
Maxime Farin ◽  
Victor C. Tsai ◽  
Michael P. Lamb ◽  
Kate E. Allstadt
Keyword(s):  
Physical Model ◽  
High Frequency ◽  
Debris Flows ◽  
Seismic Signal

scholarly journals A single particle impact model for motion in avalanches

2009 ◽  
Vol 238 (18) ◽  
pp. 1897-1908 ◽  
Author(s):  
J.J.P. Veerman ◽  
D. Daescu ◽  
M.J. Romero-Vallés ◽  
P.J. Torres
Keyword(s):  
Single Particle ◽  
Particle Impact ◽  
Impact Model ◽  
Single Particle Impact

scholarly journals The Seismic Signature of Debris Flows: Flow Mechanics and Early Warning at Montecito, California

2018 ◽  
Vol 45 (11) ◽  
pp. 5528-5535 ◽  
Author(s):  
Voon Hui Lai ◽  
Victor C. Tsai ◽  
Michael P. Lamb ◽  
Thomas P. Ulizio ◽  
Alexander R. Beer
Keyword(s):  
Early Warning ◽  
Debris Flows ◽  
Seismic Signature

An Improved Particle Impact Model by Accounting for Rate of Strain and Stochastic Rebound

2018 ◽  
Author(s):  
Steven M. Whitaker ◽  
Jeffrey P. Bons
Keyword(s):  
Experimental Data ◽  
Yield Strength ◽  
High Speed ◽  
Computational Simulation ◽  
Particle Impact ◽  
Impact Model ◽  
Model Predictions ◽  
Effective Yield ◽  
Improved Model ◽  
Deposition Models

A methodology for informing physics-based impact and deposition models through the use of novel experimental and analysis techniques is presented. Coefficient of Restitution (CoR) data were obtained for Arizona Road Dust (ARD), AFRL02 dust, and each component of AFRL02 impacting a Hastelloy X plate at a variety of flow temperatures (295–866 K), surface temperatures (295–1255 K), particle velocities (0–100 m/s), and impact angles (0–90 degrees). High speed Particle Shadow Velocimetry (PSV) allowed individual impact data to be obtained for more than 8 million particles overall, corresponding to 20 combinations of particle composition, flow temperature, and surface temperature. The experimental data were applied to an existing physics-based particle impact model to assess its ability to accurately capture the physics of particle impact dynamics. Using the experimental data and model predictions, two improvements to the model were proposed. The first defined a velocity-dependent effective yield strength, designed to account for the effects of strain hardening and strain rate during impact. The second introduces statistical spread to the model output, accounting for the effect of randomizing variables such as particle shape and rotation. Both improvements were demonstrated to improve the model predictions significantly. Applying the improved model to the experimental data sets, along with known temperature-dependent material properties such as the elastic modulus and particle density, allowed the temperature dependence of the effective yield strength to be determined. It was found that the effective yield strength is not a function of temperature over the range studied, suggesting that changes in other properties are responsible for differences in rebound behavior. The improved model was incorporated into a computational simulation of an impinging flow to assess the effect of the model improvements on deposition predictions, with the improved model obtaining deposition trends that more closely match what has been observed in previous experiments. The work performed serves as a stepping stone towards further improvement of physics-based impact and deposition models through refinement of other modeled physical processes.

scholarly journals Ground vibrations and airborne sounds generated by motion of rock in a river bed

2008 ◽  
Vol 8 (5) ◽  
pp. 1139-1147 ◽  
Author(s):  
C.-J. Huang ◽  
C.-H. Yeh ◽  
C.-Y. Chen ◽  
S.-T. Chang
Keyword(s):  
Decay Rate ◽  
High Frequency ◽  
Debris Flows ◽  
Spatial Decay ◽  
High Frequency Band ◽  
Ground Vibrations ◽  
Time Frequency ◽  
River Bed ◽  
Frequency Domains ◽  
The Impact

Abstract. This study investigates how ground vibrations (underground sounds) and airborne sounds that are produced by rocks in a river bed differ from each other. Airborne and underground sounds were simultaneously received at three microphones and three geophones, respectively. These sound signals were then analyzed using both the Fast Fourier Transform and the Gabor Transform to represent them in both the frequency and time-frequency domains. Experimental data indicate that the frequency of both airborne and underground sounds produced by the impact of rocks against the river bed is in the range 10–150 Hz. Furthermore, the high-frequency band of underground sounds decays much more rapidly than that of airborne sounds. The spatial decay rate of airborne sounds was also determined and compared with theoretical values. The lower spatial decay rate of airborne sounds than that of underground sounds suggests that monitoring of airborne sounds may be more efficient in the detection of debris flows or other natural hazards that generate both airborne and underground sounds.

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