Application And Numerical Simulation Of Vacuum Preload Reinforcement Technology For Municipal Sludge Landfill

With the improvement of urban drainage system in China,the scale of urban sewage treatment is getting larger and larger.Sludge production volume in sewage treatment plants has also increased significantly.Sludge treatment and disposal have become an important part of the operation of wastewater treatment plants.At present,conventional sludge disposal methods include sanitary landfill,sludge land use,sludge incineration or incineration power generation,and sludge landfill disposal has been widely adopted at home and abroad due to its low investment cost and wide disposal flexibility.However,with the operation of landfills,the capacity of many landfills is almost saturated.In addition,most of the landfill and sludge landfills are operated under extensive management,which results in the sludge landfill being infiltrated by rainfall or surface water,which increases the moisture content of the sludge in the sludge landfill and decreases the shear strength of the solids,resulting in sludge.The stability of the foundation of the bulk or sludge interception dam presents potential safety hazards in the landfill area of the sludge.Therefore,the local or integral reinforcement of urban sludge landfill sites has become an emergency project for many solid sanitary landfills.This article first through literature research and field investigation,analysis and comparison of common sludge treatment and disposal techniques,sludge landfill reinforcement technology characteristics and applicability,analysis of the physical and mechanical properties of solid materials in the sludge landfill,from the technology The principle and feasibility of applying the vacuum preloading method to the sludge landfill site are comparatively studied.The thesis expounds the principle of vacuum preloading method and the theory of consolidation.Based on the emergency engineering of a sludge filling plant in Chengdu,a finite element model of vacuum preloading method was established.Numerical simulation was performed using ABAQUS software and vacuum preloading was studied.Strengthen the effect of sludge disposal landfills.Simultaneously,the effects of changes in sludge properties,changes in the applied vacuum load,and changes in the condition of drainage slabs on the consolidation and settlement of sludge were compared and analyzed.The results show that the vertical settlement of the sludge in the reinforcement area increases with the permeability coefficient of the sludge.With a significant increase,with the increase in the depth of the plastic drainage board increases,reducing the spacing of the plastic drainage board for consolidation of the consolidation zone sludge limited effect,under a variety of conditions when the vacuum load caused by the settlement of the sludge accounted for At 80%of the total settling,the sludge settlement caused by the vacuum load caused 15%of the total settlement.The change of vacuum degree has little effect on the settlement and consolidation of sludge,but it has a positive effect on the consolidation rate of sludge.The conclusions drawn by the research institute in this paper can provide some reference for the reinforcement project of urban sludge landfill and provide reference for related engineering design.