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长江航道整治工程广泛采用软体排护滩,简称护滩带,当护滩带边缘压载结构不同时,边缘外的局部冲刷会发生变化。采用水槽试验的方法,研究了不同压载体护滩带边缘的局部冲刷规律。研究发现,护滩带边缘冲刷深度随水流流速与泥沙起动流速之比的增加而增大;当排体外不铺设压载体时,排体上压载体透水率越大,局部冲刷深度也越大;当排体外铺设压载体时,局部冲刷深度随压载体铺设宽度的增大呈先减小,后变化不大的特点;当排体上压载体结构和排体外压载宽度相同时,排体外压载体透水率越大,局部冲刷深度也越大。依据试验资料,选取反映水流、河床及压载结构条件的因子,建立了具有一定精度的计算排体护滩带边缘局部冲刷深度的经验公式。
The soft-shelled beach, or the beach belt, is widely used in the regulation works of the Yangtze River channel. When the ballast structure at the edge of the beach belt is different, the local erosion outside the edge will change. The method of sink test was used to study the local erosion rules of the edge of the belt with different pressure carriers. The results show that the edge washout depth of the beach belt increases with the increase of the ratio of flow velocity to sediment flow rate. When the pressure-bearing body is not laid outside, the greater the water permeability of the pressure-bearing body and the greater the local erosion depth When the paving body is laid outside the body, the local scouring depth decreases with the increase of the width of the ballast laying body first, and does not change much afterwards. When the structure of the ballast body and the ballast width of the body are the same, The greater the hydraulic conductivity of the ballast, the greater the depth of partial scour. Based on the experimental data, the factors that reflect the water flow, riverbed and ballast structure are selected to establish an empirical formula for calculating the local scour depth of the edge of the bank of a bank with a certain accuracy.