Study On Physical Characteristic Parameters Of Cargoes In Group A Of IMSBC Code

Easily-fluidized cargo is a special type of marine solid bulk cargo.During marine transportation,it is possible to form free surface or solid-liquid two-phase flow under the influence of winds,waves and mechanical vibration,which can cause vessel instability or even capsize.International Marine Solid Bulk Code defined easily-fluidized cargo in Group A,but there is no such specific classification basis of Group A cargo.Based on the understanding that easily-fluidization is inherent property of cargos,this paper summarized and screened 6 basic physical properties of cargoes as objects of the study,and studied the influence and the importance degree of relevant parameters on the attribute of easily-fluidization,and determined the characteristic parameter of non-viscous cargos from the screened basic physical properties.Hope to conclude the theoretical foundation for classification of solid bulk cargoes.Firstly this paper explained the mechanism of fluidization of cargo according to effective strength theory.After summarized the basic soil parameters that affect the properties of easy-fluidization from the IMSBC code and liquefaction possibility criterion for soils,6 basic physical properties were screened as objects of the study-Then through analyzing the results of dynamic triaxial experiment,methods for further study were determined.In order to resolve the limitation in actual operation during experiment process in practice,this paper simplified Cambridge model appropriately.A finite element model was established for analyzing deformation and pore water pressure in ABAQUS software.Through the simulation of dynamic triaxial experiment,the reliability of model was verified.Based on the numerical model,the influence of the selected characteristic parameters on the fluidization attribute was analyzed,and the importance of characteristic parameters was given.According to the numerical simulation result,the formula for calculating the time required on the condition of dynamic triaxial experiment was concluded through regression analysis.