土石流流動過程中，湧浪前端往往夾帶大量泥水及大小不一的顆粒，顆粒與水之間的作用及顆粒與顆粒接觸產生的力量在高流動速度下具有相當大破壞性。當湧浪撞擊到結構物上，動水壓及顆粒所造成的損害往往是無法預想得到的，因此要如何在土石流流動過程中逐漸減緩其撞擊力，使結構體避免直接與土石流接觸，為當前防治土石流重要的一環。 本實驗分別對於水流碰撞、顆粒流碰撞及單顆粒碰撞進行一系列測試，水流碰撞及顆粒流碰撞部份主要以不同條件下潰壩實驗來進行，分別為不同潰壩初始水深及不同顆粒鋪設高度(相同潰壩初始水深)，得出不同初始水深下影響撞擊力、流動速度及流動厚度，且最大動水壓約初始水深兩倍；不同鋪設顆粒高度下，水量、顆粒多寡及顆粒間摩擦阻力會影響撞擊力、流動速度及湧浪形成。顆粒碰撞部份主要以單擺顆粒撞擊實驗進行，利用不同高度落下撞擊不同材質物體，分別為受力鋼板及木板，得出落下高度影響撞擊速度、接觸時間及撞擊力消減程度。實驗中木板撞擊力消減程度約在70-75% 之間，但隨高度增加，撞擊力消減程度會隨之降低。期待未來能進行更多材質之撞擊力消減測試，以提供現地參考採用。 ;In the process of debris-flow movement, the front surge consisting of muddy water and particles of varied sizes is most destructive due to its high velocity. When the surge impact upon the structure occurs, the dynamic water pressure and particle-wall collision may cause unpredictable damages. Both the response of dynamic water pressure and particle-wall collision for the surge-wall interaction are experimentally examined in the study. The dynamic water pressure upon wall by a surge was analyzed by performing the dam-break experiments with varied upstream water depths. While the particle-wall collisions was carried out by the pendulum- vertical plate collision with the load-cell measurement. The dimensionless peak-pressure distribution on the wall depends on the initial upstream water depth and the free-surface slope for the surge. The maximum dynamic pressure head is about two times of the upstream water depth. The collision force depends on the impact velocity and the wall – particle stiffness. The wood board adsorbs the impact force at the degree of approximately 70-75%. However, as the impact velocity increases, the reduction ratio of the impact force decreases.
