(1. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering，Hohai University，Nanjing，Jiangsu 210098，China；2. Geotechnical Research Institute，Hohai University，Nanjing，Jiangsu 210098，China)
Abstract：Discarding the dredged sludge in the yard as waste material occupied much land，the aeration vacuum rapid mud-water separating(AVMWS) technique is suitable for discard yard with high water content and high clay particle content sludge. This technique can quickly reduce the volume of the sludge and accelerate the turnover use of the yard. More important，the technique can solve the clogging problem when pumping water from high water-content，high-clay particle content dredged sludge. Using the AVMWS technique in laboratory model test device developed by the authors，the conclusion that AVMWS technique has drainage-promotion effect on the water in sludge is drawn through the comparison of AVMWS laboratory model test and natural standing sedimentation laboratory model test. This technique can pump out much water from the dredged sludge through the filter tubes very quickly，and make the generating speed of water on the surface of sludge faster than that in natural standing sedimentation test. AVMWS technique has two drainage surfaces，and pore water seepage flows between the soil particles. Seepage generates relative flow between the solid phase and liquid phase. The relative flow makes soil particles suffering a certain tow force，and the tow force and its direction are related to constant velocity interface of relative flow. The tow force produces the process of cement-fracture compression and the rarefy effect，which make the sludge frame¢s volume compression speed faster than the speed of pump-out volume of pore water. Thus the mechanism of drainage-promotion effect of AVMWS technique has been explained.
