自航耙吸挖泥船耙头模型试验研究

为了提高自航耙吸挖泥船耙头疏浚饱和硬质土时的效率,根据模型相似的原理推导了耙头的局部模型试验方法,并通过该方法试验了不同位置高压冲水辅助下的挖掘效果,分析了垂直高压冲水和耙齿内高压冲水在耙齿挖掘中的作用,并根据两种高压冲水的作用机理,提出了沿齿面冲水的辅助挖掘新型式,进一步提高了耙头的挖掘能力和疏浚效率,同时降低了耙头的挖掘阻力.研究了耙齿对地压力、耙头吸腔密封度等因素的影响,并做出了调整和改进.结果表明,改进后的模型耙头疏浚坚硬的黄骅港密实砂质粉土时,泥浆密度换算到原型耙头可达1.19t/m3,相对于国内现有耙头同类土质下的施工密度1.10 t/m3已有大幅提高.

Model Experiments of Draghead on Training Suction Hopper Dredger

In order to improve the dredging efficiency of drag-heads on trailing suction hopper dredgers(TSHD),especially for excavating saturated stiff clay,a partial model experiment was introduced by authors based on the theory of simila-rity.With the model,they tested the excavating effects with the assistance of high pressure jets at different positions,and the function of vertical jets and jets inside the drag-teeth during dredging was analyzed.According to functional mechanism of these jets,authors put forward a new jet,which flushed along drag-teeth,improved both excavating capability and dredging efficiency,and also reduced cutting resistance.In addition,the influence of drag-teeth's pressure against riverbed and sealed degree of the draghead were also tested,and some adjustments and improvements were made.The results showed that when dredging fine hard compacted sand from Huang-Hua harbor,the improved model draghead could achieve a high slurry concentration of 1.19 t/m3,which was significantly enhanced compared to using most domestic draghead used nowadays.