Treatment Technology And Reinforcement Effect Evaluation Of Dredger Fill Subgrade

Land reclamation with dredger fill has become an important way to solve the shortage of land resources in coastal cities. Due to the general poor performance of dredger fill carrying capacity, land-based processing of dredger fill is one of the important issues in the field of geotechnical engineering. Because ofgood dispose effect, low expensive and sophisticated construction technology,it has become an important choice to process dredger fill subgrade with vacuum preloading method. After treatment,dredger fill subgrade is generally used as a building foundation. When used as a highway roadbed,because the settlement and differential settlement are more stringent,if it is to meet the engineering requirements to process dredger fill subgrade with vacuum preloading method,still requires a further examination in construction techniques and the treatment effect combined with engineering.In order to verify the feasibility of dredger fill subgrade treatment technology and test its disposition effect, this paper relies on the foundation process of Tianjin Harbor Industrial Zone at Weiliu Road as a project. It has a more detailed study on the Construction technology and construction requirements of vacuum preloading method for processing dredger fill subgrade, and tests and evaluates its disposition effect. Combined with engineering, this paper provides a brief commentary on subgrade structural design. The following is the main conclusions:(1) Construction technology research on highway foundation processing with vacuum preloading method. According to the basic design information of the engineering, the key parameters and construction technology of vacuum preloading method are designed and implemented. For the key parameters, the vacuum degree under membrane is required to maintain stability and not less than 85 kPa, the effective vacuum for a few days less than 90 days.(2) Engineering quality inspectionon highway foundation processing with vacuum preloading method. According to a long-term monitoring on soil mass nature, pore water pressure, settlement and so on, the disposition effect of vacuum preloading method is evaluated by the monitoring data. The monitoring results show that the settling volume during vacuum preloading is to meet the design requirements of unloading. The detection of the vane shear results and the physical and mechanical properties of soil before and after the treatment show that the physical and mechanical properties of soil horizon after reinforcement is improved significantly, and soil shear strength index increases markedly, achieving the purpose of the foundation treatment.(3)Structural design of dredger fill subgrade. Because the schedule may be tight, road construction needs to start after a very short timecompletingreclamation and preloading. Reclamation parts are still in poor degree of density and large water content. According to the distance between the surface and the design road after vacuum preloading,the subgradestructureis designed.In general, after vacuum preloading, dredger fill subgrade can meet the quality control requirements of highway projects, as long as design and construction closely according to engineering.