L51461 Random Seas on Pipeline Stability Vol I Wave-Soil Simulations and Simplified Design Methods

There are many ways to produce pseudo-random computer simulations of random functions correlated in space and/or time. The simulation mathematics may be performed in time and space domains or in the corresponding frequency domains. In either case, the computations may be based on the development of correlated Gaussian variables directly or on random-phase or other statistical models which are asymptotically Gaussian and which introduce the proper physical model in natural ways. The specific application to a submarine pipeline, which may move from time to time, introduces further choices. These include such approaches as a time-domain simulation just along the particular location of the pipeline, a simulation on a fixed space time grid followed by some interpolation scheme, or a Volterra integral representation of the random space-time functions involved.

The computer simulation of realistic ocean wave and sea floor soil behavior is the first part of the overall study of submarine pipeline motion under storms with random directional wave action. The second part of the study is the development and testing of finite element procedures that predict the pipeline response. The third part of the study is the development of simplifications in the system, which will allow abbreviated design guides and procedures. Most of the project effort was expended in program development and in making every effort to locate and remove computer “bugs” from the programs.