Study On The Experiment And Numerical Simulation Of Solidification For Dredged Spoils In Pipeline Mixing System

The dredged spoils of high moisture content and low intensity will be engineering fill, which is a good way to solve conflicting issues of dredged mud and coastal engineering fill. This research studied about stabilized dredged spoils used for embankment by pneumatic flow mixing method, which mainly included hardener preparation, an in-pipe mixing test system research, indoor and field experiments, CFD numerical simulation and so on. The main content includes the hardener with cement, coal ash and quick lime is acquired through the matching experiments,and the pneumatic flow mixing method translating the dredged spoils is developed by plunger type in-pipe mixing process to solidify the dredged sediments for filling soil of construction engineering. Combined with the characteristics of dredged sediments and simplifying the construction process,a test system using plunger type mixing process is designed and obtained and will provide an important theoretical significance and engineering application value for the field operation.A test system using plunger type mixing process includes hardener matching, the test device research and field test. This thesis depending on field test carried out a research of mixed results in pipe and boundary conditions,and it mainly included: hardener matching experiments and results analysis,the type selection?assembly?field test? results acquisition of test device and the strength test of dredged spoils stabilization,then provided a reference for CFD simulations;After mathematical model was established, CFD numerical simulation was carried out to rely on the field tests results,which mainly provided appropriate methods for the test device optimization.CFD numerical simulations was carried out by 6 kinds of structures,which included adjusting hardener inlet angle, air inlet angle, the distance between air inlet and expand section, the shape of expand section, the diameter of pipe and exchanging the position between air inlet and expand section. Then the phase diagram of dredged spoils in the later cross section of expand section and the volume fraction variety of each phase in pipe was plotted by TECPLOT software, finally optimization schemes was come up with. While in the different air inlet pressures, the results obtained by CFD simulation were also carried out, such as the limit of air inlet pressure, the pressure in pipe and the volume fraction variety of each phase could be obtained, and the relationship between variety of inlet hardener flow and pressure could also be obtained too, all of that provided a useful reference for the development and promotion of the test device.