通过自行研制的模型试验装置,进行了16组不同控制条件下的透气真空排水室内模型试验,得出了采用透气真空排水法各试验的淤泥试样表面水层厚度.在相同试验容器内进行相同初始含水率疏浚淤泥的自然静置沉降试验,对比了自然静置沉降试验与透气真空排水试验的表面水排出率.结果表明:透气真空排水试验的表面水层厚度大于自然静置沉降试验中的表面水层厚度;透气真空排水法能够促进淤泥向上表面排出水分.通过排水面和淤泥颗粒受力分析,从颗粒絮凝的“絮凝一断裂”沉降过程以及下部支撑淤泥层的“抽空”效应解释了透气真空排水法促进表面水排出的机理.
By use of the self-development test devices, 16 groups of laboratory aeration vacuum dewatering model tests were conducted under different control conditions. The thickness of surface water layer of each aeration vacuum dewatering test was obtained. The natural sediment tests were conducted for the dredged sludge with the same initial conditions by means of the same test devices. The dewatering efficiency of surface water of the natural sediment tests was compared with that of the aeration vacuum dewatering tests. The test results indicated that the thickness of the surface water of the aeration vacuum dewatering method is larger than that of the natural sediment tests. The aeration vacuum dewatering method can promote the water in the dredged sludge to dewater from the upper surface. Through the analysis of drainage interfaces and the stresses acting on the particles, the mechanism of promoting dewatering of the surface water by the aeration vacuum dewatering method is explained from the aspects of the "flocculation-breaking" sediment process of particle flecculation and the "pump-empty" effect of the subjacent layers.