为了解三峡工程坝下游河段控制节点演变的规律及护底试验效果, 针对宜昌枯水位的控制特点, 遴选出胭脂坝、南阳碛、芦家河浅滩等控制节点, 在原型观测资料的基础上分析了坝下游河段控制节点的演变趋势及其对宜昌枯水位的控制特性, 并对控制节点之一的胭脂坝节点护底保护试验工程进行了长期跟踪观测和分析研究, 认为采用抛石填槽、砼系结块软体排护底工程对河床防冲效果明显, 护底工程不仅很好地保护了河床, 同时对河段还有一定的加糙壅水作用, 从而在一定程度上抑制了宜昌枯水位的下降。

In the present paper, we analyzed the fluvial process and the effect of riverbed protection of key points in the downstream of Three Gorges Project. In line with the characteristics of low water level at Yichang station, we selected Yanzhiba, Nanyangji and Lujiahe as the key points for controlling, and analyzed their fluvial processes as well as their impact on the water level at Yichang station based on prototype observation. Moreover, we carried out long-term monitoring on the effect of riverbed protection at Yanzhiba. Results reveal that measures including blocking deep groove by dumping stones and protection with geosynthetics mattress with concrete block has apparent effect of protection and anti-erosion for riverbed, and at the same time roughens the riverbed for backwater effect, which somehow restrains the water level decreasing at Yichang station.