Three-dimensional geomechanics experimental investigation on potential impulse waves generated by Wangjiashan landslide in Baihetan Reservoir, China

Landslides and the associated secondary disasters in reservoir areas are typically abrupt and catastrophic in nature. To address this challenge, prototype physical model experiments have been demonstrated to be effective tools for simulating these geological disasters. Following the impoundment of the Baihetan Hydroelectric Reservoir on the Jinsha River, the deformation and damage to the Wangjiashan (WJS) landslide intensified significantly. The Xiangbiling (XBL) residential area, along with the surrounding villages on the opposite bank, faces a significant risk of surge waves. This study, based on the WJS landslide, constructed a large-scale three-dimensional physical model (at a 1:150 scale) that integrates landslide, river, and residential area interactions. The model dimensions are 65 × 40 × 3 m3. Physical model experiments on landslide-generated surge waves were conducted under the conditions of an 825 m water level and seismic activity to explore the temporal and spatial evolution of the entire life cycle of the surge waves from the WJS landslide. Experimental results indicate that the XBL residential area was completely submerged under the wave impact. To mitigate the risk of surge wave disasters, the study proposed controlling surge wave size as an indicator for assessing landslide surge wave risk prevention and control. Through slope reduction and load-reduction engineering measures, the threat in the 4.5 km stretch of the reservoir's upstream and downstream channels was eliminated. The findings provide crucial experimental data and theoretical support for understanding the physical mechanisms underlying landslide-generated surge waves, as well as for early warning and disaster prevention.