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Yin Y.-P.,China Institute for Geo Environment Monitoring
Landslides | Year: 2015

The Qianjiangping landslide occurred on July 13, 2003 when water level in the Three Gorges Reservoir in China reached 135 m a.s.l. for about 1 month. Thirteen people on the slope and 11 fishermen on boats in the nearby area were killed by this landslide and its wave. As a typical case, the Qianjiangping landslide is researched extensively, but the wave itself was studied much less. In this paper, a fluid–solid coupling model based on general moving objects (GMO) collision model and renormalisation group (RNG) turbulent model were employed, simplifying the sliding motion of the Qianjiangping landslide as a rigid body circular motion whose validity was verified by comparing with actual survey conditions related. Numerical simulation analysis shows that in the Qianjiangping landslide event, the solid–fluid energy-transferring rate was 5.97 %, while the motion of sliding mass could push and raise water body. The maximum-modelled wave run-up generated by the Qianjiangping landslide was 40.4 m (up to 175.4 m a.s.l.), while the maximal observed one was 39 m. It was the solitary wave, and the wave celerity was 32∼36 m/s or so. The hazardous river length of impulse wave was estimated to be 12.6 km, where wave height was more than 1 m high. The fluid–solid coupling numerical model employed by this paper can provide important reference for wave generated by other landslides around the world. Research of the landslide-generated wave is very significant in landslide hazard reduction and prevention. © 2015, Springer-Verlag Berlin Heidelberg.

Yin Y.,China Institute for Geo Environment Monitoring | du C.,Chongqing Institute of geological disaster prevention and control
Landslides | Year: 2016

On June 24, 2015, Hongyanzi slope located in Wushan County of the Three Gorges Reservoir collapsed, generating 5–6-m-high impulse waves, which overturned 13 boats, killed 2 persons, and injured 4 persons. It is the second incident of landslide-generated impulse waves since the 175-m experimental impoundment in 2008. The emergency investigation shows that Hongyanzi landslide is a bedding soil landslide with a volume of 23 × 104 m3 induced by a series of triggering factors such as rainfall, flooding upstream, and reservoir drawdown. The nonlinear Boussinesq water wave model is used to reproduce the impulse waves generated by the landslide of June 24th. The numerical simulation results suggest that the wave propagation process was influenced by the T-shaped geomorphic conditions of river valley, and the coastal areas in the county seat were the major wave-affected areas, which is opposite to the landslide. The numerical wave process accord well with the observed incident, and the investigation values were in good agreement with the calculated values. Moreover, the worst-case scenario of the 7 × 104 m3 deformation mass beside Hongyanzi landslide is potential to generate impulse waves, which was predicted with the same numerical model. This adjacent deformation mass will probably generate impulse waves with maximum height and run-up of 2.2 and 2.0 m, respectively, and only a very few areas in the water course had waves rising to a height of 1 m or above. The research results provide a technical basis for emergency disposal to Hongyanzi landslide and navigation restriction in Wushan waterway. More importantly, it pushes the risk management of the navigation based on the impulse wave generated by landslide. It is advised that the Three Gorges Reservoir and other reservoirs around the world should put more efforts in performing special surveys and studies on the potential hazards associated with landslide-generated impulse waves. © 2016 Springer-Verlag Berlin Heidelberg

Huang B.,Hubei Engineering University | Yin Y.,Hubei Engineering University | Yin Y.,China Institute for Geo environment Monitoring
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2013

Impulsive wave generated by landslide is a complex and dynamic process, wave propagation overly extended the dangerous range of landslide. Landslide impulsive wave simulation adopted wave dynamic model is hot in relative field in foreign, which can efficiently simulate long wave propagation problems. In this paper, the authors introduce wave dynamic model and form fast assessing system for tsunamis generated by geo-hazard(FAST) supported by GIS technology. FAST is made up of pre-processing module, simulation module, and post processing module, which can calculate impulsive wave according to the type of landslide failure, and can intuitively display water elevation change condition of point, line, surface and volume. It has characteristics of manageability, high efficiency and visibility. The paper takes Maocaopo landslide in Wu Gorge of Three Gorges Reservoir for example, and forecast impulsive wave generated by this landslide, verifying the feasibility and utility of FAST. The simulation result shows that the maximum wave amplitude is 25 m, the maximum run-up height is 12.5 m, and after landslide failure 444.5 s, a 2.5 m run-up wave will arrive in Wushan County. This soft offer a new analysis method and visualization platform for early warning and risk assessment work on geo-hazard impulsive wave in reservoir.

Huang B.,Hubei Engineering University | Yin Y.,Hubei Engineering University | Yin Y.,China Institute for Geo Environment Monitoring | Jiang Z.,Yangtze River Scientific Research Institute
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2013

Impulsive wave events generated by landslides have the sudden and catastrophic characteristics, for which investigation information is very limited; so prototype physical experiment study is a good method in this condition. Taking impulsive wave event of Gongjiafang slump mass in Three Gorge reservoir area for the prototype, a big physical similarity model with the length of 24 m, width of 8 m, height of 1.3 m, is established, which is the first prototype model on main stream after the reservoir impounding. The model similarity ratio is 1:200. Marble grit(d50 = 1.47 mm) is used to simulate cataclastic rockmass in the test, using 15 wave gauges, high-speed cameras and run-up instruments to monitor wave process; and six sets of impulsive wave tests with the variable of impulse velocity into water in the front of the landslide are conducted. The comparison between test results and investigation results show that the test method can be used to study or forecast impulsive wave generated by similar cataclastic rockmass failure. After analyzing a series of test data, waves interactive process is showed firstly with the help of the gauge data, for example, wave chasing, superposition and reflection wave superposition. The data also finely portrait the wave propagation and run-up decay ratio in the riverway. Through this prototype model test, the improvement direction of the experiment on impulsive wave generated by cataclastic rockmass failure is discussed. The method used in this paper can offer references for impulsive wave generated by cataclastic rockmass failure, and the results obtained can provide great technical support for forecasting impulsive wave generated by other similar slopes of Three Gorges reservoir area.

Huang B.,Wuhan University | Yin Y.,Wuhan University | Yin Y.,China Institute for Geo Environment Monitoring | Jiang Z.,Changjiang River Science Research Institute | Liu J.,University of Wisconsin - Madison
Landslides | Year: 2014

Landslide-related impulse waves are catastrophic but accidental, so limited data on field measurements are available; scaled physical experiment is therefore a functional method to simulate and analyze this phenomenon. A large-scale physical Froude-similar model to produce impulse waves was constructed based on the Chinese Gongjiafang landslide, which occurred on the main stream of Three Gorges after the impounding in the reservoir in China. With a scale of 1:200, the model had the dimensions of 24, 8, and 1.3 m. Four water levels, 145, 156, 172.8, and 175 m, were modeled for the experiments, and marble coarse sands were used to imitate the actual cataclastic rock mass. Wave height gauges, high-speed cameras, and run-up measuring instruments were used to monitor wave fluctuations in the model. Among the experiments, the ones modeled using a water level of 172.8 m best confirmed the actual conditions in the Gongjiafang landslide, representing a good validation of the experiments. This study obtained, for the first time, specific data on the reproduced impulse waves' convergence and superposition during propagation, and of the energy change between impulse waves and reflected waves. The test data describe a rapid decaying and gradual decaying rule for the wave heights and run-ups. The Froude-similar experiments presented in this article help us to understand the whole procedure of impulsive wave generated by cataclastic rock mass failure, and the results acquired contribute to studies of impulse waves caused by similar bank destabilizations worldwide. © 2013 Springer-Verlag Berlin Heidelberg.

Yin Y.,China Institute for Geo Environment Monitoring
Environmental Earth Sciences | Year: 2015

An impulse wave generated by landslide is a major detriment to waterway safety in reservoirs. Thick-bedded pillar-shaped rockmass is one of the principal potential tsunami generators in the Three Gorges Reservoir and other reservoirs around the world. However, the impulse wave generated by a pillar-shaped rockmass was seldom studied in the past. The Jianchuandong dangerous rockmass lies on the left bank of Yangtze River in the Wu Gorge of the Three Gorges Reservoir with a total volume of 36 × 104 m3 or so, standing as a serious threat to the safety of the waterway, a renowned “expressway”. Along with the deterioration of the base mass, the Jianchuandong rockmass is likely to either slide or topple due to instability. A solid–fluid coupled computational fluid dynamic model is built to calculate the potential impulse wave induced by the Jianchuandong dangerous rockmass. The potential impulse waves under four working conditions with two failure modes and two water levels are discussed. Numerical simulation results show that the potential maximum wave height and maximum run-up are 47.1 and 27.2 m, respectively. Based on the integrated calculation results, we deduce a 15 km channel segment likely to be affected by the Jianchuandong rockmass-induced impulse wave for early warning purpose. By engineering geological analogy, the calculation results are verified with the instance data of two impulse wave events generated by landslides in the Three Gorges Reservoir. The purpose of this study is to provide a technical support for early warning, prevention and control of hazards associated with the Jianchuandong dangerous rockmass and to serve as a reference for researches on impulse wave generated by pillar-shaped rockmass collapse around the world. © 2015, Springer-Verlag Berlin Heidelberg.

Huang B.,Wuhan University | Yin Y.,China Institute for Geo Environment Monitoring
Landslides | Year: 2012

At 4:40p. m. on November 23, 2008, the Gongjiafang slope collapsed on the north bank of Yangtze River in Wu Gorge of Three Gorges Reservoir. The 380,000-m 3 sliding mass consisted mainly of cataclastic rock. A video record of the major sliding incident was analyzed using the general laws of physical motion. The analysis indicated that the maximum speed and maximum acceleration of the sliding mass were 11. 65 m/s and 2. 23 m/s 2, respectively, and that the maximum amplitude and the propagation velocity of the water wave near the landslide were 31. 8 m and 18. 36 m/s, respectively. Wave run-up investigation indicated that the maximum run-up on shore was 13. 1 m, which declined to 1. 1 m at Wushan dock 4 km away. The incident causes no casualties, but did result in economic losses of RMB five million. The numerical simulation model GEOWAVE was used to simulate and reproduced the impulse wave generated by the landslide; the results were in good agreement with the observed incident. The numerical simulation data were then applied to analyze the decay and amplification effects of the landslide wave in the river course. The field investigations and witness information provide valuable materials for the studies of landslide kinematics and impulse waves generated by landslides. In addition, the research results provide a useful reference for future similar waves generated by landslides in reservoirs. © 2012 Springer-Verlag.

Zhang Z.,208 Geological Team of Chongqing City | Yin Y.,China Institute for Geo environment Monitoring | Fei M.,Chongqing Three Gorges University
Quarterly Journal of Engineering Geology and Hydrogeology | Year: 2016

Pillar-shaped rock masses are widely developed throughout the world with some standing firm for thousands of years. Unstable pillar-shaped rock masses display different failure modes and it is often difficult to determine in advance the specific failure mode of a complex rock mass. For example, the displacement deformation of the Jianchuandong rock mass(JRM) in the Three Gorges Reservoir Area has been about 20 mm over the last 2 years. With a volume of 360 000 m3, this unstable pillar-shaped rock mass stands on the bank of the Yangtze River's Wu Gorge, threatening the safety of the waterway and the residents of neighbouring areas. Developing Hungr's quantitative discriminant on the rock collapse and rock slump modes, several cases are used to verify its validity. The failure mode of the JRM is judged to be rock collapse. This judgement matches well with the actual field survey and monitoring data. For pillar-shaped unstable rock masses with a rock collapse failure mode, this paper develops a new slope stability calculation mode by deeming the intact pillar-shaped rock mass to be the load. The result of such a stability calculation shows that the JRM is basically stable at present, but the safety margin is extremely narrow. Prevention work should be carried out as soon as possible for better results at a lower investment before the JRM experiences large-scale deformation and failure. © 2016 The Author(s).

Huang B.,Hubei Engineering University | Yin Y.,Hubei Engineering University | Yin Y.,China Institute for Geo Environment Monitoring
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2014

Physical prototype test can be used to verify the validity and accuracy of numerical simulation result. The authors compare Gongjiafang landslide physical prototype model test with numerical simulation result, which is based on water wave dynamic theory. This research suggests that the simulation can reproduce the water wave interaction phenomena in the physical test, and the water level process lines match well. There are some errors between the values from physical test and numerical simulation, which is rooted in the tsunami source model. Numerical simualation based on water wave dynamic theory has the character of validity and accuracy. This method can offer scientific basis to assess impulse wave hazard generated by landslides in long distance and large region valley, which would be the hot issue in this field in the future. This result will benefit to popularize and apply numerical simulation method based on wave dynamics.

Liu C.-Z.,China Institute for Geo Environment Monitoring | Miao T.-B.,Gansu Bureau of Surveying and Mapping | Chen H.-Q.,China Institute for Geo Environment Monitoring | Dong K.-J.,Gansu Institute for Geo Environment Monitoring | And 2 more authors.
Geological Bulletin of China | Year: 2011

The Zhouqu event happened at 0:12 of Aug. 8, 2010 in Zhouqu County of Gansu Province of China. It is an oversize mountain torrent-debris flow disaster which brought about momentous casualty and loss of belongings. It is finished with Aug. 30. There are 1467 death and 298 lost having been discovered in this disaster. It is calculated for that total volume of the solid deposits are 181×104m3 which rush out from Sanyanyu and Luojiayu gullies through grid calculation. The movement time from two mountains to Zhouqu County is separately 2.1 minutes for Sanyanyu and 4.3 minutes for Luojiayu on velocity calculation of the mountain torrent head in different sections in this disaster. The distances from two mountains to Zhouqu County are all about 2km in Sanyanyu and Luojiayu. The causes of formation about Zhouqu tragedy involved Sanyanyu being a debris flow gully of high frequency in history, the northern mountainous area producing strong potential energy impulsion, a rich of loosing rock or soil body in the gullies, rockmass loosing and cracking derived from many times of historical earthquakes, a long period of drought in this region since 2010 made in rock/soil body crack opening, the maximum rainfall to cause this calamity in the area at Aug. 7, the mountain torrent-debris being of concealment in gestation, abruptness in happening and truculency in destruction, etc. Moreover, some buildings occupy and use partly the routeway in which a torrent-debris flows into Bailongjiang River in Zhouqu County in rapid urbanization.

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