Study on energy dissipation mechanism of front-blocking structures for landslide surge in reservoir areas

Landslide disasters in reservoir areas are a common threat to reservoir safety, with secondary surges caused by landslide instability posing potential risks such as impacts on the dam body and overtopping. Traditional wave walls have limited capacity to withstand surge impacts, necessitating the exploration of wave-blocking pier arrays capable of effectively intercepting high-energy surge run-ups. Based on outdoor physical model tests, this study systematically investigates the energy dissipation mechanism of front-blocking structures for landslide surges, utilizing high-speed camera monitoring. The interaction between surges and blocking structures in front of the dam is analyzed, and the relationships and sensitivity coefficients between surge maximum run-up reduction rate and factors such as pier height, pier spacing, array layout position, and inter-row spacing in double-row pier arrays are obtained. The experimental results indicate that the relative height of piers is the primary factor affecting the maximum run-up reduction rate in single-row arrays, while in double-row arrays, the reduction rate is positively correlated with inter-row spacing. Finally, a calculation formula for the maximum surge run-up reduction rate under single-row arrays is derived through multiple nonlinear regression analysis, providing theoretical support for surge mitigation and prevention in reservoir areas affected by landslides.