(1.Hubei Key Laboratory of Disaster Prevention and Mitigation，Yichang，Hubei 443002，China；2. College of Civil Engineering and Architecture，China Three Gorges University，Yichang，Hubei 443002，China；3. China Geological Environment Monitoring Institute，Beijing 100081，China；4. China Three Gorges Corporation，Chengdu，Sichuan 443002，China)
Abstract：A large number of reservoir-induced landslides caused disasters in the form of impulse waves in western China. If all landslides that may generate waves are prevented and controlled by current specification，the economic cost is huge. This paper taking Shuipingzi 1# landslide in Baihetan reservoir as an example to carry out application demonstration，a three-dimensional physical prototype model experiment was constructed with a geometric scale of 1∶150，and landslide energy reduction and wave descent experiments were carried out to find more economical landslide-induced impulse wave risk reduction solution. Physical test showed that under extreme conditions of the impounding water level with 825 m above sea level combined with a VIII-degree earthquake，the landslide would slide into Baihetan reservoir with the maximum speed of 7.37 m/s，and the maximum generated wave amplitude would be 7.59m. The maximum runup around Xiangbiling community was about 3.5 m above the ground，which would seriously threaten the safety of the riverway with the length of more than 4.5 km and the safety of Xiangbiling community. As the removal volume increases from 10×104 m3 to 47.9×104 m3，the effect of reducing energy and wave becomes evident. Wave making energy transmitted from landslide decreased by about 94.8%，the maximum wave amplitude and the maximum runup around the Xiangbiling decreased to 4.35 m and 1.73 m，respectively. The area with the impulse wave larger than 1 m was only distributed in the landslide course and the opposite bank of Jinsha River，and the risk of landslide-induced impulse wave decreased sharply. Based on this，this study proposes and discusses the feedback design mentality and the realization method of the safety margin of landslide-induced impulse wave risk reduction engineering design，which using the hazard degree of landslide-induce impulse wave as a measurement indicator，and recommends a risk reduction design scheme that can greatly reduce the economic cost of Shuipingzi 1 #landslide treatment. The design mentality of risk reduction prevention for landslide-induced impulse wave is a useful supplement of landslide control specification，which has yet to be further developed and promoted.
