Preliminary Research On Virtual Safety System For Submarine Pipeline

Virtual Safety System for Submarine Pipeline is an integrated desktop application aiming at safety analyzing and simulating of submarine pipelines. In the first place, the paper introduces the basic frame of Virtual Safety System for Submarine Pipeline. The concept and idea of the system are explained in terms of technology compositions, data requirement, functional modules, conceptual models and developing approaches. The data standardization method is involved in describing the data clearly, enhancing the sharing ability and improving the intercommunion with other systems. Then, the data standardization system including data element programming, metadata model constructing and information classifying and coding is established. According to the submarine pipeline data characteristics, the information of submarine pipeline is divided into two parts, spatial information and attribute information. The problem of how to store spatial information in the relational database is solved. Spatial information and attribute information are connected by identifiers. Combined with relational database technology and GIS technology, a PODS-based data model with topology rules is established.On-bottom stability analysis of submarine pipelines and vibration simulation of free span pipelines are the critical functions of the system. Two mathematical models are established for these two functions, and the corresponding computer programs are developed separately. The model for on-bottom stability analysis of submarine pipelines is established on the basis of a DNV recommended practice, which includes two methods, simplified method and generalized method, and both methods can be used for both clay and sand. Using FEM, Gauss elimination, Newmark integral etc., assuming that the soil is linear springs, the vibration simulation model of free span pipelines is established to simulate the mode, static response, and dynamic response of the free span pipelines. Finally, the simulation validity of the paper is verified by comparing with the one of the ANSYS nonlinear soil spring supporting model.