世界遗产元阳梯田加固田埂降雨侵蚀机理研究

STUDY ON MECHANISM OF RAINFALL EROSION REINFORCEMENT IN WORLD HERITAGE YUANYANG TERRACE FIELD

世界遗产元阳梯田老虎嘴观景台下方发生滑坡-泥石流地质灾害并冲毁梯田约9.79 hm~2。为了加固田埂、修复梯田,通过室内模型试验,分析模拟降雨条件下不同田埂注浆加固工况的梯田模型侵蚀发育情况和模型内部体积含水率、孔隙水压力、基质吸力、土压力变化规律及其坡面流速、产流产沙特征,以研究降雨条件下注浆固梗侵蚀机理。结果表明:注浆固梗增强了田埂截流作用,其具有减水减沙效益,并且对于细沟发育有调控作用。注浆固梗减缓梯田侵蚀发展速度,不改变其侵蚀发展模式。注浆固梗的减水减沙效益随雨强增大而减小。

The geological disaster of landslide-debris flow occurred beneath the viewing platform of the Yuanyang terrace, a world heritage site, resulting in the erosion and loss of 146.8 mu of terrace area. To reinforce the ridge and restore the terrace, an investigation was conducted on the grouting reinforcement mechanism under rainfall conditions through indoor model testing. This study analyzed the erosional development, variations in internal volumetric water content, pore water pressure, matrix suction, and soil pressure, characteristics of flow and sediment yield, as well as characteristics of overland velocity. The findings revealed that: grouting reinforcement enhances the blocking effect of the ridge, which has the benefit of reducing water and sediment, and has the regulation effect on the development of rill. The grouting and reinforcement of terraced fields slow down the erosion development speed and do not change the erosion development mode. The benefit of water and sediment reduction of the grouting and reinforcement decreases with the increase of rain intensity.