Coefficient of restitution and kinetic energy loss of rockfall impacts

Li, Liping; Sun, Shangqu; Li, Shucai; Zhang, Qian‐qing; Hu, Cong; Shi, Shaoshuai

doi:10.1007/s12205-015-0221-7

Cited by 29 publications

(8 citation statements)

References 14 publications

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“…e kinetic energy loss is small when the junction of slope and the accumulation area is a curved slope break; when the junction has sharp edges, the kinetic energy loss is larger [13,22]. Under the experimental conditions, in which slope height H and volume are constant, as the slope angle increases, energy loss also increases due to the collision of the flowslide and the horizontal plate at the slope break [43,44], which results in shorter distance of movement of the sliding body. e slope angle in the chalk flow area is too large, and the energy loss is excessive though the sliding path is lubricated by water beneath the accumulation area 1-2 m. e flowslides in Wenchuan affected by lubrication due to water are few.…”

Section: Advances In Civil Engineeringmentioning

confidence: 85%

An Analysis of Factors Affecting Flowslide Deposit Morphology Using Taguchi Method

Duan

Tang

et al. 2020

Advances in Civil Engineering

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Flowslides, as one type of landslides, are becoming a research hotspot due to their high speed and long runout distance, which can cause tremendous damage and economic loss. The scale of damage and deposit morphology of flowslide is closely related to factors like deposit volume, slope height, and slope angle. In order to assess the influence of these factors, a sandbox apparatus is developed, and the Taguchi method is used to design an experimental scheme to analyze the results of factors affecting the deposit morphology of flowslide. The results show that the factor that has the greatest impact on flowslide deposit morphology is slope angle, followed by the influence of volume and slope height. As slope angle increases, the maximum width, maximum length, area, and length-width ratio of the deposit first increase and then decrease. In addition, there should be a critical angle in the changes of deposit morphology that is between 60° and 70° under the experimental conditions. When the volume is 5.4 × 10−3 m3, the slope angle is 70°, the slope height is 0.90 m, and the changes of deposit morphology of the flowslide are the largest. In this study, considering the slope angle as a single variable, there is a single upheaval for a slope angle of 40° and 50° and a double upheaval at 60° and 70°. The formation mechanism of the upheaval is analyzed based on the Mohr-Coulomb criterion and considered properties of the material. The apparent friction coefficient of a flowslide is spatially and lithologically different and increases nonlinearly as the slope angle increases. The initial benchmark of the slope angle and apparent friction coefficient curve are affected by the friction coefficient of the material; the position of the inflection point at which the curve increases rapidly is affected by the coefficient of velocity restitution.

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Section: Advances In Civil Engineeringmentioning

confidence: 85%

An Analysis of Factors Affecting Flowslide Deposit Morphology Using Taguchi Method

Duan

Tang

et al. 2020

Advances in Civil Engineering

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“…(2) e objective function y � f x (z, m v ) in (11)fd11 is an uncertainty function, which was represented using the neural network model described in Section 2.3.1. (3) Using the historical rockfall data, the normal and tangential coefficients of restitution [33][34][35] and the friction angle of the Guanyindong Slope were determined using the theory of displacement back analysis (Figure 8) [32]. Based on the parameters, RocFall 2D software was used to simulate possible rockfall events for each cross profile and to obtain sample data for these rockfall events.…”

Section: Field Investigation Resultsmentioning

confidence: 99%

Engineering Application and Prediction of the Influence Area of the Rockfall Hazards

Liao

Wang

et al. 2020

Mathematical Problems in Engineering

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The identification of potential rockfall and the accurate prediction of its trajectory are critical in prevention and mitigation of rockfall hazard. It is an important precondition to assess the uncertainty of rockfall motion, study the effective identification technology of potential rockfall, predict the rockfall trajectory, and calculate the threatened area by rockfall hazards. In this study, field investigations and numerical simulations were carried out to identify potential rockfall on a weathered rock slope. As a case study, our calculations results show that the area of tensile stress concentration and plastic failure is the potential area where the rockmass will fall off the surface of the weathered rock slope. A mathematical model for calculating the rockfall influence area of the weathered rock slope was established based on the optimization theory, neural network technology, and genetic optimization algorithm. The rockfall influence area of the weathered rock slope was determined using maximum horizontal distance of rockfall in the specified slope cross sections and described on the topographic map using spline curves to form a closed possibly vulnerable area. As a case study, our calculations confirm that the distributions of the plastic failure and tensile stress areas obtained from the numerical simulations are consistent with the dangerous rock masses identified by field investigations at Guanyindong Slope that is a popular tourist scenic spot in Zhejiang Province, China. In this study, it has been indicated that the influence area can be used as the basis for the design of passive protection methods for rock slopes vulnerable to rockfall hazards.

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“…Essentially, the motion trajectories of the blocks are the external manifestation of their total kinetic energies. The total kinetic energy (including translational and rotational) can be increased owing to the transformation of gravitational potential energy during the downward movement of the block, or can be dissipated through collisions between the block and the slope, and among blocks (Li et al 2016;Zhu et al 2019). It can be said that the kinetic energy and motion trajectory are the main basis for determining the strength as well as the location and scale of rockfall protection structures.…”

Section: Introductionmentioning

confidence: 99%

Three-Dimensional Discontinuous Deformation Analysis of Failure Mechanisms and Movement Characteristics of Slope Rockfalls

Liu

2021

Rock Mech Rock Eng

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A rockfall is a typical dynamic problem of a discontinuous block system originating from a dangerous rock mass and always presents serious geo-hazards along highway slopes in mountainous areas. This study aims to investigate the failure mechanisms and movement characteristics of rockfalls through a three-dimensional discontinuous deformation analysis (3D DDA) method and attempts to comprehensively examine the complicated kinematic process of rockfall disasters. In terms of the initial failure and post-movement characteristics (i.e., motion trajectory and kinetic energy) of a rockfall, the effectiveness of 3D DDA is verified by comparing its results with those of laboratory experiments. Taking the K4580 typical high-steep slope undergoing rockfalls along the G318 national highway in Tibet as an example, the initiation and failure of a single boulder and a large-scale rock mass at the source area were simulated by 3D DDA. Then, the movement characteristics of the boulder and massive collapsing rocks along the slopes of different geometrical characteristics, i.e., the slopes before the landslide and after the shallow and deep landslides, were studied. The results show that the 3D DDA has significant advantages in analysing the failure mechanisms of slope rockfalls and can satisfactorily simulate the spatial movement (e.g., lateral deviation and deflection) of blocks by considering the 3D geometry of the slopes and blocks. The 3D DDA numerical simulation can predict the movement range, deposition position, and affected area of rockfall disasters, which can provide a basis for formulating disaster prevention countermeasures in actual projects.

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Coefficient of restitution and kinetic energy loss of rockfall impacts

Cited by 29 publications

References 14 publications

An Analysis of Factors Affecting Flowslide Deposit Morphology Using Taguchi Method

An Analysis of Factors Affecting Flowslide Deposit Morphology Using Taguchi Method

Engineering Application and Prediction of the Influence Area of the Rockfall Hazards

Three-Dimensional Discontinuous Deformation Analysis of Failure Mechanisms and Movement Characteristics of Slope Rockfalls

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