Experimental Study On Mechanical Properities Of Dredged Sludge Under Vacuum Preloading And Heating

The combination of vacuum preloading and heating is an effective technique to accelerate the consolidation rate of soil.However,the effect of soil reinforcement is not obvious at lower temperature,and the higher temperature will consume a lot of energy.In the process of vacuum preloading treatment,because the dredge is mainly composed of fine soil particles,with the development of time,fine soil particles gradually gather towards the drainage plate,making the permeability around the drainage plate decrease.In view of the above problems,this paper further studies and discusses the treatment of dredged silt by vacuum preloading combined with heating on the basis of predecessors.The main research is as follows:(1)Through the thermal consolidation test and the permeability test,the soil volume has an irreversible volume contraction under the thermal consolidation test,while the permeability test under heating has a linear relationship between the pore ratio and the logarithm of the soil permeability coefficient,and the decrease of the soil permeability coefficient is only related to the viscosity of water with the increase of temperature.(2)Reclamation silt reinforcement effect under different heating ways of study,carried out in laboratory model test,under the vacuum preloading,by adopting different heating mode(constant temperature heating and heating mode),based on the different pore pressure,settlement of soil under constant temperature,water content,strength index and energy consumption were analyzed,the optimal strengthening temperature of 75 ℃.(3)Study on the effect of dredging silt reinforcement under different cycle paths.The optimal heating path is 30℃-75 ℃-30 ℃ by changing different cycle paths.(4)The higher the heating rate is,the larger volume shrinkage and drainage will occur during the early heating process,but the rate of soil consolidation slows down in the later stage.When the heating rate is low,the soil consolidation rate is slow in the early stage,but accelerated in the later stage.