Analysis of waves generated by Gongjiafang landslide in Wu Gorge, three Gorges reservoir, on November 23, 2008

Vast expanse of land in northwest China is covered by loess. Because of the characteristics of loess, mud flow disasters can be induced in this area easily. Worse still, due to the mud flow gully transformation and the environmental changes in recent decades, mud flow disasters are increasing. In order to know more about gullyshaped mud flow, the field investigation of more than 60 gullies and the similarity principle were applied to determine the test parameters and a physical model of gully was made for mud flow. During the tests, the motion characteristics (velocity, acceleration and intermittent debris flow) and deposition parameters (length, width, area, aspect ratio, distribution, shape and thickness) of mud flow in the model were collected and analyzed. The instantaneous velocities of the mud flow fluctuated. Discharge exerts a maximum impact on the velocity; second is unit weight and minimum slope angle. In the transportation zone, the mud flow flows and forms the bed firstly; then the intermittent debris flow occurs which is affected by discharge and unit weight. The length, width and area of deposition have a certain linear rule and distribution pattern greatly relates to the first accumulation. The stacking thickness is decreasing from the center to the edge.

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“…1, v i?1 is the realtime velocity in the period i ? 1, and a is the acceleration during the interval Huang et al 2012). …”

Section: Test Resultsmentioning

confidence: 99%

Experimental study on gully-shaped mud flow in the loess area

et al. 2015

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“…Impulse waves are usually generated in reservoirs, rivers, lakes, and seas as rock/soil masses impact water, resulting in huge economic losses and casualties (Wang et al, 1986;Fritz 2001;Scheffers and Kelletat, 2003;Alvarez-Cedrón et al, 2009;Silvia et al, 2011;Huang et al, 2012). This fact urges people to pay attention to landslide-induced impulse waves, which is an interdisciplinary study related to rock/soil mechanics and fluid mechanics.…”

Section: Introductionmentioning

confidence: 99%

“…In the single simulation method for a landslide-induced impulse wave, the phase of landslide movement and granular masswater body interaction is regarded as the formation of the initial impulse wave, and generally the motion of the sliding mass is considered to the motion of a rigid block. Therefore, various kinematic formulas, such as Newton's laws of motion, are applied to calculate the motion of the sliding mass (Heller, 2009;Huang et al, 2012Huang et al, , 2016. Then, various empirical or experimental formulas of landslide-induced impulse waves are adopted to calculate the characteristics of the initial impulse wave caused by the landslide (Walder et al, 2003;Tappin et al, 2008;AtaieAshtiani and Malek Mohammadi, 2007).…”

Section: Introductionmentioning

confidence: 99%

Analysis of the Tangjiaxi landslide-generated waves in the Zhexi Reservoir, China, by a granular flow coupling model

Huang

Yin

Wang

et al. 2017

Nat. Hazards Earth Syst. Sci.

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Abstract. A rocky granular flow is commonly formed after the failure of rocky bank slopes. An impulse wave disaster may also be initiated if the rocky granular flow rushes into a river with a high velocity. Currently, the granular masswater body coupling study is an important trend in the field of landslide-induced impulse waves. In this paper, a full coupling numerical model for landslide-induced impulse waves is developed based on a non-coherent granular flow equation, i.e., the Mih equation. In this model, the Mih equation for continuous non-coherent granular flow controls movements of sliding mass, the two-phase flow equation regulates the interaction between sliding mass and water, and the renormalization group (RNG) turbulence model governs the movement of the water body. The proposed model is validated and applied for the 2014 Tangjiaxi landslide of the Zhexi Reservoir located in Hunan Province, China, to analyze the characteristics of both landslide motion and its following impulse waves. On 16 July 2014, a rocky debris flow was formed after the failure of the Tangjiaxi landslide, damming the Tangjiaxi stream and causing an impulse wave disaster with three dead and nine missing bodies. Based on the full coupling numerical analysis, the granular flow impacts the water with a maximum velocity of about 22.5 m s −1 . Moreover, the propagation velocity of the generated waves reaches up to 12 m s −1 . The maximum calculated run-up of 21.8 m is close enough to the real value of 22.7 m. The predicted landslide final deposit and wave run-up heights are in a good agreement with the field survey data. These facts verify the ability of the proposed model for simulating the real impulse wave generated by rocky granular flow events.

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“…As previous stated, the maximum velocity of the slide mass is 11.65m/s. According to the study by Huang (2012), the slide mass had experienced two phases of movement. In the first step, the slide mass accelerated to 11.65m/s in about 13s.…”

Section: Kinematics Of the Landslidementioning

confidence: 99%

“…Although the failure firstly occurred in the foot part of the slope, but the entire rock mass still kept intact and moved at the same time. The maximum velocity of the slide mass was estimated to be 11.65m/s (Huang et al 2012). The profile of the slope before and after the failure has been depicted in Fig.5.…”

Section: Gongjiafang Landslidementioning

confidence: 99%

Modeling of landslide generated waves in Three Gorges Reservoir, China using SPH method

Wang

Chen

Yin

et al. 2016

JGS Special Publication

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To investigate the wave characteristics generated by subaerial landside in Three Gorges Reservoir, China, a large laboratory physical experiment was conducted. Specially, the channel of Baishuihe landslide in the reservoir was selected as prototype and reproduced with scale of 1:200 under the similarity conditions. A series of test with different collocation of parameters were performed. Empirical equations were derived by the means of dimensionless analysis and multiple nonlinear regression. The proposed equations were then used to quickly predict the wave features (maximum wave amplitude, runup, and wave attenuation) of Gongjiafang landslide in the Wu Gorge. Numerical simulation of waves generated by Gongjiafang landslide was carried out using DualSphysics which is a SPH method based application. Comparison between the wave features derived from the numerical simulation and the prediction equations was looked insight. Results show better agreements of both methods either in maximum wave amplitude and runup. In Addition, wave characteristics (wave length, velocity and period) were well analyzed using the wave gauges' data in the numerical simulation. It can be concluded that the modeling work using SPH method should be well adopted in investigating the problems of landslide generated waves in detail, while the equations derived from the experiment enable a quick basis in the prediction of the main wave features. Combination of both methods will be an excellent way in analyzing the practical case and thus provides significant means for hazard assessment and prevention.

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Analysis of waves generated by Gongjiafang landslide in Wu Gorge, three Gorges reservoir, on November 23, 2008

Cited by 95 publications

References 9 publications

Experimental study on gully-shaped mud flow in the loess area

Experimental study on gully-shaped mud flow in the loess area

Analysis of the Tangjiaxi landslide-generated waves in the Zhexi Reservoir, China, by a granular flow coupling model

Modeling of landslide generated waves in Three Gorges Reservoir, China using SPH method

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