Abstract

In this paper, a new approach is adopted to prevent channel incision and the consequent water level lowering, which aims to maintain the water depth in navigation channel. By pavement of gravels on the channel bed in certain locations, not only the roughness of the channel is increased but also the channel bed is prevent from erosion for the function of bed armoring, thus, the process of water level lowering will be stopped and water stage even will be elevated by roughness increment. Theoretical analysis shows that the effectiveness of the measure is closely related to the diameter of the roughness material to be used. Stability of the works, increase of water depth, variations of hydraulic gradient and velocity distribution in navigation channel after increasing of roughness must be comprehensively studied to prevent from harmful influences on navigation. This engineering measure is applied to solve the problem of insufficient water depth of navigation channel probably occurred to the ship lock of the Gezhouba Project when the Three Gorges Project is put into operation.

Keywords: channel incision; water depth deficiency; increasing roughness; increase of water depth