Numerical Simulation of Vacuum Preloading for Chemically Conditioned Municipal Sludge

Municipal sludge is a sedimentation waste produced during the wastewater process in sewage treatment plants. Among recent studies, pilot and field tests showed that chemical conditioning combined with vacuum preloading can effectively treat municipal sludge. To further understand drainage consolidation characteristics of preloading, large deformation nonlinear numerical simulation model based on equal strain condition was developed to simulate analyze tests, whereas results were not satisfactory. The analysis test predicted degree greater than measured by which attributed relatively low permeability layer formed prefabricated vertical drain. better reflect conditioned sludge, simplified method considering around drain proposed. initial coefficient determined via simulations using finite difference method. settlement curve good agreement results, indicated ferric chloride-conditioning preloading.